ISO 26824:2022 粒子系の粒子特性 - 用語、語彙 | ページ 6

3.1.1

粒子

物理的な境界が定義された微小な物質

注記 1物理的境界は、インタフェースとして記述することもできます。

注記2:粒子はユニットとして移動できる。

注記 3:この一般的な粒子の定義は、 ナノオブジェクト (3.1.7) に 適用されます。

[出典:ISO 26824:2013, 1.1]

3.1.2

凝集する

結果として得られる外部表面積が個々の構成要素の表面積の合計に類似する、弱くまたは中程度に強く結合した 粒子（3.1.1） の集合。

注記 1:凝集物を一緒に保持する力は弱い力であり、例えば、ファン デル ワールス力や単純な物理的絡み合いなどです。

注記2凝集体は二次粒子とも呼ばれ，元の粒子は 一次粒子と呼ばれる（3.1.4） 。

[出典:ISO 26824:2013, 1.2]

3.1.3

骨材

得られた外部表面積が個々の成分の表面積の合計よりも著しく小さい、強力に結合または融合した粒子を含む 粒子（3.1.1） 。

注記1集合体を一緒に保持する力は，例えば共有結合，焼結や複雑な物理的絡み合い，あるいは以前の 一次粒子の結合によるものなどの強い力である (3.1.4) 。

注記2集合体は二次粒子とも呼ばれ，元の粒子は 一次粒子と呼ばれる(3.1.4) 。

[出典:ISO 26824:2013, 1.3]

3.1.4

一次粒子

凝集体（3.1.2） or 凝集体（3.1.3） の元の 粒子（3.1.1） またはその 2 つの混合物。

注記1 凝集体(3.1.2) or 凝集体(3.1.3) の 構成粒子(3.1.5) は，ある実際の状態で一次粒子となり得るが，多くの場合，構成成分は凝集体である。

注記2 凝集体（3.1.2） 及び 凝集体（3.1.3） は二次粒子とも呼ばれる。

[出典:ISO 26824:2013, 1.4]

3.1.5

構成粒子

より大きな 粒子（3.1.1） の識別可能な不可欠な成分。

注記1構成粒子構造は， 一次粒子（3.1.4） or 凝集体（3.1.3） であってもよい。

注記 2:図 1 を参照。

[出典:ISO/TS 80004-2:2015, 3.3, 修正 — 図 1 が追加され、注 1 が修正され、注 2 と 3 が追加された]

3.1.6

ナノスケール

約 1 nm から 100 nm までの長さの範囲

注記 1:より大きなサイズからの外挿ではない特性は、主にこの長さの範囲で示されます。

[出典:ISO/TS 80004-1:2015, 2.1]

3.1.7

ナノオブジェクト

ナノスケール（3.1.6） で 1 つ、2 つ、または 3 つの外形寸法を持つ個別の材料片

注記2 番目と 3 番目の外形寸法は，1 番目の寸法と互いに直交している。

[出典:ISO/TS 80004-1:2015, 2.5]

3.1.8

ナノマテリアル

ナノスケール（3.1.6） の外部寸法を持つ材料、またはナノスケールの内部構造または表面構造を持つ材料

[出典:ISO/TS 80004‑1:2015, 2.4]

3.1.9

粒子サイズ

x

d

特定の測定方法及び特定の測定条件下で決定される 粒子（3.1.1） の直線寸法。

注記1:さまざまな分析方法は、さまざまな物理的特性の測定に基づいています。実際に測定された粒子の特性とは無関係に、粒子サイズは直線 寸法 として報告されます。

注記2サイズ記述子の例は，ふるいの目開きまたは画像解析によって測定されたフェレ径などの統計的直径に基づくものである。

注記 3: ISO 9276 では、記号「 x 」を使用して粒子サイズを表します。ただし、記号「 d 」もこれらの値を示すために広く使用されていることが認識されています。したがって、記号 ' x ' は ' d ' に置き換えることができます。 [ISO 9276-1:1998, 3.1]

[出典:ISO 9276-1:1998, 4.2, modified – text reformated]

3.1.10

等価直径

球相当径

測定対象の 粒子（3.1.1） によって生成された応答と同等の、特定の粒子サイズ法による応答を生成する球の直径。

注記 1等価直径が参照する物理的性質は、適切な添え字を使用して示される [ISO 9276-1:1998

注記2:個別の粒子計数、光散乱装置については、同等の光学直径が使用されます。

注記 3:粒子の密度などの他の材料定数は、ストークス直径または沈降等価直径などの等価直径の計算に使用されます。計算に使用される材料定数も報告する必要があります。

注記4慣性計器については，空気力学的直径が使用される。空気力学的直径は、不規則粒子と同じ沈降速度を持つ密度 1 000 kg m ^-3の球の直径です。

[出典:ISO/TS 80004‑6:2021, 4.1.5]

3.1.11

量の種類

r

分布、 累積（3.1.13） または密度測定 （3.1.14） の量の仕様。

[出典:ISO 9276-1:1998, 4.3]

3.1.12

粒度分布

粒子サイズ（3.1.9） の関数としての 粒子（3.1.1） の分布

注記1粒度分布は 累積分布（3.1.13） または 分布密度（3.1.14） （あるサイズクラスの材料の割合をそのクラスの幅で割った分布）として表すことができる。

[出典:ISO/TS 80004‑6:2013, 3.1.2]

3.1.13

累積分布

Q _r ( x )

所定の 粒子サイズ（3.1.9） よりも小さい（アンダーサイズの）物質の割合の分布。

注記 3累積オーバーサイズ分布は 1 − Q _r ( x ) で与えられる。

[出典:ISO 9276-1:1998, 5.2]

3.1.14

分布密度

q _r ( x )

そのクラスの幅で割ったサイズ クラスの材料の割合の分布

注記2より一般的な「密度分布」という用語は、沈降法の文脈では誤解される可能性があるため、別の方法が採用されています。

注記3:微分分布は、統計では「確率または頻度の密度」とも呼ばれます。

[出典:ISO 9276-1:1998, 5.3, 修正 – 「密度分布」を「分布密度」に置き換え]

3.1.15

対数横軸の分布密度

q * _r ( x )

対数横座標に変換された 分布密度 (3.1.14)

注記 2自然対数を 10 を底とする対数に置き換えた場合にも、この等式は成り立つ。

[出典:ISO 9276-1:1998, 6.2]

3.1.16

ヒストグラム

[出典:ISO 9276-1:1998, 5.1]

3.1.17

濃度分布密度

そのクラスの幅で割ったサイズ クラスの材料の濃度の分布

注記 1:エアロゾル測定では、例えば、粒子数濃度の分布密度は、粒子サイズの関数として表されます。

注記2濃度分布密度は， 粒子径（3.1.9） の 分布密度（3.1.14） 関数に測定濃度を乗じて算出することができる。

3.1.18

分析カットサイズ

x_a

置き忘れた材料を同量含む粗い材料と細かい材料のカット サイズ

注記1分類プロセスによって決定される微細な材料の相対質量は、飼料中のサイズの小さい材料の相対質量、つまりQ_3,s ( x )に等しいと見なされるため、分析カットこの定義に対応するサイズxを見つける必要があります。

[出典:ISO 9276-4:2001, 4.3.2]

3.1.19

等確率カットサイズ

x_e

等級効率 (3.1.20) 曲線の中央値を表すカットサイズT ( x_e ) = 0.5

注記1細粒分と粗粒分の加重分布密度曲線は，等確率カットサイズx_eで交差する。他の 粒子サイズ (3.1.9) とは無関係に、このサイズの粒子は、細かい部分と粗い部分に分類される確率が等しくなります。

[出典:ISO 9276-4:2001, 3.3.2]

3.1.20

等級効率

T ( x )

等級効率 (トロンプ曲線、部分分級効率) は、特定の 粒子サイズ (3.1.9) x 原料に最初に存在する同じサイズの量に対する、粗い材料に存在する材料の量の比率を表します。

[出典:ISO 9276-4:2001, 4.4]

注記1：集塵分野では、この効率を部分分離効率と呼んでいます。

3.1.21

参考資料

rm

1つ以上の指定された特性に関して十分に均質で安定しており、測定プロセスでの使用目的に適合することが確立されている材料。

注記1 RMは総称である。

注記2:特性は、物質または種の同一性など、量的または質的である場合があります。

注記3：用途には、測定システムの較正、測定手順の評価、他の材料への値の割り当て、および品質管理が含まれる場合があります。

注記 4: ISO/IEC Guide 99:2007 にも同様の定義がありますが、「測定」という用語を定量的な値に適用するように制限しています。ただし、ISO/IEC Guide 99:2007, 5.13, 注 3 (VIM) には、「公称特性」と呼ばれる定性的特性が具体的に含まれています。

[出典:ISO Guide 35:2017, 3.1]

3.1.22

認定標準物質

CRM

参照物質（3.1.21） 。特定の特性の価値、関連する不確かさ、及び計量トレーサビリティの記述を提供する RM 証明書を伴う、1 つ以上の特定の特性に対する計量学的に有効な手順によって特徴付けられる。

注記1価値の概念には，同一性や順序などの名目上の特性または質的属性が含まれる。そのような属性の不確実性は、確率または信頼レベルとして表される場合があります。

注記 2 RM の製造と認証のための計量学的に有効な手順は、特に ISO 17034 と ISO Guide 35 に記載されています。

注記 3: ISO Guide 31 は、RM 証明書の内容に関するガイダンスを提供します。

注記 4: ISO/IEC Guide 99:2007, 5.14 には類似の定義があります。

[出典:ISO Guide 35:2017, 3.2]

3.1.23

正確さ

試験結果または測定結果と 真の値（3.1.26） との間の一致の近さ。

注記1実際には，受け入れられた参照値が 真の値に置き換えられる（3.1.26） 。

注記2: 「精度」という用語は、一連の試験または測定結果に適用される場合、ランダム成分と一般的な系統誤差またはバイアス成分の組み合わせを含みます。

注記3精度とは， 真度（3.1.25） と 精度（3.1.24 ）の組み合わせをいう。

[出典:ISO 3534-2:2006, 3.3.1]

3.1.24

精度

規定された条件下で得られた独立した試験/測定結果間の一致度

注記1精度はランダム誤差の分布のみに依存し， 真の値（3.1.26） または指定された値とは関係ありません。

注記2精度の尺度は通常、不正確さで表され、試験結果または測定結果の標準偏差として計算されます。精度が低いと、標準偏差が大きくなります。

注記3:精度の定量的尺度は規定された条件に決定的に依存する.再現 性条件 (3.1.28) および再現性条件は、規定された極端な条件の特定のセットです。

[出典:ISO 3534-2:2006, 3.3.4]

3.1.25

真実

試験結果又は測定結果の期待値と 真の値（3.1.26） との間の一致の近さ。

注記1真実性の尺度は通常，偏りによって表現される。

注記2真偽は「平均値の正確さ」と呼ばれることがある。この使用法はお勧めしません。

注記3実際には、受け入れられた参照値が真の値に置き換えられます。

[出典:ISO 3534-2:2006, 3.3.3]

3.1.26

真価

量または量的特性が考慮されるときに存在する条件で完全に定義された量または量的特性を特徴付ける値

注記 1量または量的特性の真の値は理論上の概念であり、一般に正確に知ることはできません。

注記 2 「量」という用語の説明については、ISO 3534-2:2006, 3.2.1 の注 1 を参照してください。

[出典:ISO 3534-2:2006, 3.2.5]

3.1.27

再現性

再現性条件下での精度 (3.1.28)

注記1:再現性は、結果の分散特性に関して定量的に表すことができます。

[出典:ISO 13320:2020, 3.1.20]

3.1.28

再現性条件

同一の試験・測定施設内の同一の試験・測定項目について、同一の操作者が同一の機器を使用し、同一の方法で短時間に独立した試験・測定結果が得られる観測条件

[出典:ISO 3534-2:2006, 3.3.6]

3.1.29

メソッドの再現性

同じ測定者が同じ機器を使用して同じ条件で短時間に実行した、サンプルの異なるアリコートでの特定の特性の複数の測定結果間の一致度。

注記 1:変動性には，サブサンプリング技術，サンプリングされた物質の変動性及び機器の変動性が含まれる。

[出典:ISO 13320:2020, 3.1.22]

3.2.1

particle shape

external geometric form of a particle (3.1.1)

Note 1 to entry: Macroshape is a description of the overall form of a particle (3.1.1) defined in terms of the geometrical proportions of the particle. In general, simple geometrical descriptors calculated from size measurements made on the particle silhouette are used.

Note 2 to entry: Mesoshape description provides information about details of the particle shape and/or surface structure that are in a size range not much smaller than the particle proportions.

Note 3 to entry: Microshape determines the roughness of shape boundaries using fractal dimension or higher-order Fourier coefficients for surface-textural analysis.

[SOURCE:ISO/TS 80004‑6: 2021, 4.1.3, modified — Notes 1 to 3 have been added from ISO 9276-6:2008, 5.2]

3.2.2

Legendre ellipse of inertia

ellipse with its centre at the particle’s centroid and with the same geometrical moments of inertia, up to the second order, as the original particle area

Note 1 to entry: The ellipse can be characterized by its major and minor diameters, the position of its centre of gravity and its orientation.

Note 2 to entry: Macroshape descriptor, geometrical descriptor

[SOURCE:ISO 9276-6:2008, 8.1.2]

3.2.3

geodesic length and thickness

x_lg and x_E

Note 1 to entry: Macroshape descriptor, geometrical descriptor

[SOURCE:ISO 9276-6:2008, 8.1.2]

3.2.4

ellipse ratio

ratio of the lengths of the axes of the Legendre ellipse of inertia (3.2.3)

Note 1 to entry: Macroshape descriptor, proportion descriptor

[SOURCE:ISO 9276-6:2008, 8.1.3]

3.2.5

Feret diameter

x_F

distance between two parallel tangents on opposite sides of the image of a particle (3.1.1)

[SOURCE:ISO 13322-1:2014, 3.1.5]

3.2.6

aspect ratio

ratio of the minimum Feret diameter to the maximum Feret diameter (3.2.5)

Note 1 to entry: For not very elongated particles (approximately smaller than 1:3)

Note 2 to entry: Macroshape descriptor, proportion descriptor

[SOURCE:ISO 9276-6:2008, 8.1.3, modified — 'Feret diameter' is inserted after 'minimum.']

3.2.7

elongation

ratio of the geodesic thickness to the geodesic length (3.2.3)

Note 1 to entry: For very elongated particles (approximately greater than 1:3), such as fibres

Note 2 to entry: Macroshape descriptor, proportion descriptor

[SOURCE:ISO 9276-6:2008, 8.1.3]

3.2.8

straightness

ratio of the maximum Feret diameter (3.2.5) to the geodesic length (3.2.3)

Note 1 to entry: For very elongated particles (reciprocal of curl)

Note 2 to entry: Macroshape descriptor, proportion descriptor

[SOURCE:ISO 9276-6:2008, 8.1.3]

3.2.9

irregularity

ratio of the diameter of the maximum inscribed circle d_imax and that of the minimum circumscribed circle d_cmin

Note 1 to entry: Macroshape descriptor, proportion descriptor, (modification ratio)

[SOURCE:ISO 9276-6:2008, 8.1.3]

3.2.10

compactness

s

Note 1 to entry: Macroshape descriptor, proportion descriptor

[SOURCE:ISO 9276-6:2008, 8.1.3]

3.2.11

box ratio

ratio of the Feret box area to the projected area A

Note 1 to entry: Macroshape descriptor, proportion descriptor

[SOURCE:ISO 9276-6:2008, 8.1.3]

3.2.12

sphericity

Ψ

Note 1 to entry: Wadell’s sphericity Ψ , also derived from surface area S

Note 2 to entry: Mesoshape descriptor

[SOURCE:ISO 9276-6:2008, 8.2]

3.2.13

circularity

C

Note 1 to entry: Mesoshape descriptor, also derived from the area equivalent diameter x_A to the perimeter equivalent diameter x_P

[SOURCE:ISO 9276-6:2008, 8.2]

3.2.14

solidity

S_l

Note 1 to entry: Measure of the overall concavity of a particle

Note 2 to entry: Mesoshape descriptor

[SOURCE:ISO 9276-6:2008, 8.2]

3.3.1

molecular cross-sectional area

molecular area of the adsorbate, i.e. the area occupied by an adsorbate molecule in the complete monolayer

[SOURCE:ISO 9277:2010, 3.10]

3.3.2

free space

volume of the sample holder not occupied by the sample

Note 1 to entry: also called head space, dead space, or dead volume

[SOURCE:ISO 9277:2010, 3.14]

3.3.3

specific surface area

absolute surface area of the sample divided by sample mass

[SOURCE:ISO 9277:2010, 3.15]

3.3.4

blind pore

dead end pore

open pore having a single connection with an external surface

Note 1 to entry: also called dead-end-pore

[SOURCE:ISO 15901-2:2006, 3.6]

3.3.5

closed pore

pore totally enclosed by its walls and hence not interconnecting with other pores and not accessible to fluids

[SOURCE:ISO 15901-1:2016, 3.10]

3.3.6

open pore

pore not totally enclosed by its walls and open to the surface either directly or by interconnecting with other pores and therefore accessible to fluid

[SOURCE:ISO 15901-1:2016, 3.11]

3.3.7

open porosity

ratio of the volume of open pores and voids to the total volume occupied by the solid

[SOURCE:ISO 15901-2:2006, 3.17]

3.3.8

contact angle

angle at which a liquid/vapour interface meets the surface of a solid material

[SOURCE:ISO 15901-1:2016, 3.32]

3.3.9

ink bottle pore

narrow necked open pore

[SOURCE:ISO 15901-1:2016, 3.12]

3.3.10

interconnected pore

pore which communicates with one or more other pores

[SOURCE:ISO 15901-2:2006, 3.9]

3.3.11

intraparticle porosity

ratio of the volume of open pores inside the individual particles of a particulate or divided solid sample to the bulk volume occupied by the sample

[SOURCE:ISO 15901-1:2016, 3.29]

3.3.12

interparticle porosity

ratio of the volume of void space between the individual particles to the bulk volume of the particles or powder

[SOURCE:ISO 15901-1:2016, 3.28]

3.3.13

macropore

pore of internal width greater than 50 nm

[SOURCE:ISO 15901-1:2016, 3.7]

3.3.14

mesopore

pore of internal width between 2 nm and 50 nm

[SOURCE:ISO 15901-1:2016, 3.8]

3.3.15

micropore

pore of internal width less than 2 nm

[SOURCE:ISO 15901-1:2016, 3.9]

3.3.16

supermicropore

pore with width of approximately 0,7 nm – 2 nm

[SOURCE:ISO 15901-2:2022, 3.14]

3.3.17

ultramicropore

pore with width of approximately < 0,7 nm

[SOURCE:ISO 15901-2:2022, 3.15]

3.3.18

nanopore

pore with width of 100 nm or less

Note 1 to entry: The concept of nanopore overlaps all three traditionally defined major pore size ranges with micropore (pore with width of about 2 nm or less), mesopore (pore with width between approximately 2 nm and 50 nm), and macropore (pore with width greater than about 50 nm) and therefore is not based on sorption behavior or principles. See also Reference [16].

[SOURCE:ISO 15901-2:2022, 3.10, modified — Note 1 has been added]

3.3.19

pore size

internal pore width (e.g. the diameter of a cylindrical pore or the distance between the opposite walls of a slit) which is a representative value of various sizes of vacant space inside a porous material

[SOURCE:ISO 15901-1:2016, 3.13]

3.3.20

pore volume

volume of open pores unless otherwise stated

[SOURCE:ISO 15901-1:2016, 3.14]

3.3.21

porosimeter

instrument for measuring pore volume and pore size distribution

[SOURCE:ISO 15901-1:2016, 3.1]

3.3.22

porosimetry

methods for the estimation of pore volume, pore size distribution, and porosity

[SOURCE:ISO 15901-1:2016, 3.2]

3.3.23

porosity

ratio of the volume of the accessible pores and voids to the bulk volume occupied by an amount of the solid

[SOURCE:ISO 15901-1:2016, 3.27]

3.3.24

porous solid

solid with cavities or channels which are deeper than they are wide

[SOURCE:ISO 15901-1:2016, 3.3]

3.3.25

surface area

extent of accessible surface area as determined by a given method under stated conditions

[SOURCE:ISO 15901-1:2016, 3.30]

3.3.26

surface tension

work required to increase a surface area divided by that area.

[SOURCE:ISO 15901-1:2016, 3.31]

3.3.27

through pore

pore which passes all the way through the sample

[SOURCE:ISO 15901-1:2005, 3.27]

3.3.28

void

interstice

space between particles, i.e. an interparticle pore

[SOURCE:ISO 15901-1:2016, 3.6]

3.3.29

adsorbate

adsorbed gas

[SOURCE:ISO 15901-2:2022, 3.1]

3.3.30

adsorbed amount

amount of gas adsorbed at a given pressure, p, and temperature, T

[SOURCE:ISO 15901-2:2022, 3.6]

3.3.31

adsorbent

solid material on which adsorption occurs

[SOURCE:ISO 15901-2:2022, 3.4]

3.3.32

adsorption

enrichment of the adsorptive gas at the external and accessible internal surfaces of a solid material

[SOURCE:ISO 15901-2:2022, 3.2]

3.3.33

adsorptive

gas or vapour to be adsorbed

[SOURCE:ISO 15901-2:2022, 3.3]

3.3.34

equilibrium adsorption pressure

pressure of the adsorptive gas in equilibrium with the adsorbate

[SOURCE:ISO 15901-2:2022, 3.7]

3.3.35

adsorption isotherm

relationship between the amount of gas adsorbed and the equilibrium pressure of the gas, at constant temperature

[SOURCE:ISO 15901-2:2022, 3.5]

3.3.36

monolayer amount

amount of the adsorbate that forms a monomolecular layer over the surface of the adsorbent

[SOURCE:ISO 15901-2:2022, 3.8]

3.3.37

monolayer capacity

volumetric equivalent of monolayer amount expressed as gas at standard conditions of temperature and pressure (STP)

[SOURCE:ISO 15901-2:2022, 3.9]

3.3.38

relative pressure

ratio of the equilibrium adsorption pressure, p, to the saturation vapour pressure, p₀, at analysis temperature

[SOURCE:ISO 15901-2:2022, 3.19]

3.3.39

right cylindrical pore

cylindrical pore perpendicular to the surface

[SOURCE:ISO 15901-2:2022, 3.19]

3.3.40

saturation vapour pressure

vapour pressure of the bulk liquefied adsorptive gas at the temperature of adsorption

[SOURCE:ISO 15901-2:2022, 3.20]

3.3.41

volume adsorbed

volumetric equivalent of the amount adsorbed, expressed as gas at standard conditions of temperature and pressure (STP), or expressed as the adsorbed liquid volume of the adsorbate

[SOURCE:ISO 15901-2:2022, 3.21]

3.3.42

physisorption

weak bonding of the adsorbate, reversible by small changes in pressure or temperature

[SOURCE:ISO 15901-2:2022, 3.16]

3.3.43

powder

porous or nonporous solid composed of discrete particles with maximum dimension less than about 1 mm, powders with a particle size below about 1 μm are often referred to as fine powders

[SOURCE:ISO 15901-1:2016, 3.4]

3.3.44

pore

cavity or channel which is deeper than it is wide, otherwise it is part of the material’s roughness

[SOURCE:ISO 15901-1:2016, 3.5]

3.3.45

pore diameter

diameter of a pore in a model in which the pores typically are assumed to be cylindrical in shape and which is calculated from data obtained by a specified procedure

[SOURCE:ISO 15901-1:2016, 3.15]

3.3.46

median pore diameter

diameter that corresponds to the 50th percentile of pore volume, i.e. the diameter for which one half of the pore volume is found to be in larger pores and one half is found to be in smaller pores

[SOURCE:ISO 15901-1:2016, 3.16]

3.3.47

modal pore diameter

mode

pore diameter of the maximum in a differential pore size distribution curve

[SOURCE:ISO 15901-1:2016, 3.17]

3.3.48

hydraulic pore diameter

average pore diameter, calculated as the ratio of pore volume multiplied by four to pore area

[SOURCE:ISO 15901-1:2016, 3.18]

3.3.49

density

ratio of the mass of a certain amount of a sample to the volume occupied by that mass

[SOURCE:ISO 12154:2014, 3.1]

3.3.50

true solid state density

ratio of the sample mass to the volume of the compact solid skeleton of the sample which excludes the volume of open and closed pores or internal voids and also interparticle voids as in the case of granulated or highly dispersed samples

[SOURCE:ISO 12154:2014, 3.2]

3.3.51

bulk volume

volume of powder or solids, including all pores (open and closed) and interstitial spaces between particles

[SOURCE:ISO 15901-1:2016, 3.19]

3.3.52

bulk density

ratio of sample mass to bulk volume

[SOURCE:ISO 15901-1:2016, 3.20]

3.3.53

skeleton volume

volume of the sample including the volume of closed pores (if present) but excluding the volumes of open pores as well as that of void spaces between particles within the bulk sample

[SOURCE:ISO 15901-1:2016, 3.21]

3.3.54

skeleton density

ratio of sample mass to skeleton volume (3.3.53)

[SOURCE:ISO 15901-1:2016, 3.22; ISO 12154:2014, 3.3]

3.3.55

apparent volume

total volume of the solid constituents of the sample including closed pores and pores inaccessible or not detectable by the stated method

[SOURCE:ISO 15901-1:2016, 3.23]

3.3.56

apparent density

ratio of sample mass to apparent volume

[SOURCE:ISO 15901-1:2016, 3.24]

3.3.57

envelope volume

total volume of the particle, including closed and open pores, but excluding void space between the individual particles

[SOURCE:ISO 15901-1:2016, 3.25]

3.3.58

envelope density

ratio of sample mass to envelope volume (3.3.57)

[SOURCE:ISO 15901-1:2016, 3.26]

3.4.1

sedimentation

directional motion of particles in a viscous liquid under the action of gravity or centrifugal fields

Note 1 to entry: For a positive density contrast, sedimentation occurs in the direction of gravitational acceleration; it is counter directed to this acceleration for a negative density contrast.

Note 2 to entry: A downward motion under gravity is also called settling or falling.

Note 3 to entry: An upward motion under gravity is also called creaming (for liquid particles) or more general rising and floating.

[SOURCE:ISO 13317-1:— ¹ , 3.1]

3.4.2

migration

directional motion of particles in a viscous liquid under the action of a force field

Note 1 to entry: For a positive density contrast, migration occurs in the direction of gravity or centrifugal acceleration; it is counter directed to this acceleration for a negative density contrast.

[SOURCE:ISO 13317-1:—, 3.2]

3.4.3

terminal sedimentation velocity

sedimentation velocity in case that gravity or centrifugal force is completely balanced by buoyancy and drag force

[SOURCE:ISO 13317-1:—, 3.3]

3.4.4

Stokes diameter

equivalent diameter of a sphere that has the same buoyant density (3.4.12) and terminal sedimentation velocity (3.4.3) as the real particle in the same liquid under creeping flow (3.4.15) conditions

Note 1 to entry: The general rule that the buoyant density (3.4.12) is used for calculating the Stokes diameter applies also to coated particles or multiconstituent particles (such as droplets in multiple emulsion). The buoyant density (3.4.12) can be approximated with the skeletal density (3.4.10) for monoconstituent particles.

Note 2 to entry: For porous particles, it is common use to compute particle size based on the apparent particle density (3.4.11) . This approach considers the stagnant liquid in the open pores as intrinsic constituent of the dispersed phase. Thus obtained size values are hydrodynamic equivalent diameters.

Note 3 to entry: For closed-packed agglomerates or aggregates, the buoyant density (3.4.12) can be replaced by the apparent particle density (3.4.11) – with particle referring to the agglomerate/aggregate – in order to get the hydrodynamic equivalent diameter.

[SOURCE:ISO 13317-1:—, 3.4]

3.4.5

shape correction factor

<sedimentation analysis> ratio of the sedimentation velocity of a non-spherical particle to the one of a spherical particle of the same volume and density

[SOURCE:ISO 13317-1:—, 3.5]

3.4.6

hindrance function

ratio of the terminal sedimentation velocity (3.4.3) of a particle placed in well-mixed dispersion divided by its sedimentation velocity in an infinite vessel for the absence of other particles

[SOURCE:ISO 13317-1:—, 3.6]

3.4.7

dynamic viscosity

characteristic of flow resistance for Newtonian liquids which is calculated as ratio of the shear stress to the rate of shear for laminar flow exposed to a pre-set shear stress or strain

[SOURCE:ISO 13317-1:—, 3.11]

3.4.8

apparent viscosity

viscosity value for non-Newtonian liquids under a defined shear stress or strain, calculated as ratio between the shear stress and the rate of shear

[SOURCE:ISO 13317-1:—, 3.12]

3.4.9

true density of the dispersed phase

ratio of mass to volume for a body solely consisting of the dispersed phase without pores, voids, inclusions or surface fissures

[SOURCE:ISO 13317-1:—, 3.13]

3.4.10

skeletal density

<sedimentation analysis> ratio of mass to volume for a monoconstituent body defined by its external surface

Note 1 to entry: The skeletal density of a monoconstituent particle refers to the volume occupied by the dispersed phase including internal voids (i.e. closed pores (3.3.5) ), whereas open pores (3.3.6) and surface fissures are not counted.

[SOURCE:ISO 13317-1:—, 3.14, ISO 18747-1:2018, modified - to be applicable to non-solid particles]

3.4.11

apparent particle density

effective particle density

ratio of mass to volume for a particle including particulate inclusions, entrapped stagnant liquid and gas in pores, voids and surface fissures as well as surfaces layers and coatings

Note 1 to entry: The a. p. d. is the density of a migrating entity and is calculated as weighted average of its constituents.

Note 2 to entry: The a. p. d. depends on wettability of open pores and the kinetics of wetting or replacement of pore liquid. Therefore, it is affected by sample preparation.

Note 3 to entry: The a. p. d. is not identical with the buoyant density (3.4.12) . They deviate from each other in particular for porous particles and particle agglomerates.

[SOURCE:ISO 13317-1:—, 3.15]

3.4.12

buoyant density

ratio of mass to volume for a particle including particulate inclusions, liquid and gas in closed pores and voids as well as surfaces layers and coatings but excluding the liquid continuous phase that penetrates open pores

Note 1 to entry: The buoyant density equals the (hypothetical) density of the continuous phase for which the gravitational force acting on the immersed particle is counterbalanced by buoyancy.

Note 2 to entry: The buoyant density of a particle can be experimentally determined (ISO 18747-1, ISO 18747-2)

Note 3 to entry: The buoyant density. of monoconstituent particles can be approximated with their skeletal density (3.4.10) .

Note 4 to entry: The buoyant density of multiconstituent particles (e.g. coated pigments, droplets of multiple emulsions) can be approximated with the averaged skeletal densities of the single constituents.

Note 5 to entry: The buoyant density is affected by the adsorption of dissolved species at the particle surface and therefore depends on the solvent and its composition.

Note 6 to entry: The buoyant density is not identical with the apparent particle density (3.4.11) . This holds particularly true for porous particles and particle agglomerates.

[SOURCE:ISO 13317-1:—, 3.16]

3.4.13

density contrast

difference between the buoyant density of the dispersed phase and the density of the continuous phase

[SOURCE:ISO 13317-1:—, 3.17]

3.4.14

particle Reynolds number

dimensionless characteristic (number) for the flow behaviour of moving particles defined as the ratio of inertial force to viscous force

Note 1 to entry: The particle Reynolds number is based on the volume equivalent diameter.

Note 2 to entry: In other contexts, the definition of the p.R.n. may refer to different equivalent diameters or to the equivalent radii.

[SOURCE:ISO 13317-1:—, 3.18]

3.4.15

creeping flow

type of flow that is solely governed by viscous forces and not affected by inertial effects

Note 1 to entry: For moving particles or for the flow past a particle, the creeping flow condition holds approximately true if the particle Reynolds number (3.4.14) is well below 0,25.

[SOURCE:ISO 13317-1:—, 3.19]

3.4.16

Brownian motion

random motion of particles caused by collisions with the molecules or atoms of the surrounding continuous phase

Note 1 to entry: The trajectory of Brownian motion is not differentiable.

Note 2 to entry: Brownian motion results on a macroscopic level in mass transport of the dispersed phase; e. g. in case of diffusion, thermophoresis or photophoresis.

[SOURCE:ISO 13317-1:—, 3.20]

3.4.17

sensitivity

change of instrument response with respect to changes in concentration or absolute quantity of particles in a specified size class

Note 1 to entry: Concentration or quantity can be given in relative or absolute values in dependence on the detection aim.

Note 2 to entry: Sensitivity depends on the type of quantity (3.1.11) .

Note 3 to entry: Sensitivity is a function of size.

[SOURCE:ISO 13317-1:—, 3.24]

3.4.18

limit of quantity detection

smallest quantity of specified particle size class, for which the instrument response can be distinguished from the background

Note 1 to entry: It depends on the size range, on precision, noise level, smoothing algorithms etc.

Note 2 to entry: It affects the lower and upper size limit.

[SOURCE:ISO 13317-1:—, 3.25]

3.5.1

dead time

time during which the electronics are not able to detect particles due to the signal processing of a previous pulse

[SOURCE:ISO 13319-1:2021, 3.1]

3.5.2

aperture

orifice

small-diameter hole through which suspension is drawn

[SOURCE:ISO 13319-1:2021, 3.2, modified – orifice has been added]

3.5.3

analysis volume

volume of suspension that is analysed

[SOURCE:ISO 13319-1:2021, 3.4]

3.5.4

sensing zone

volume of electrolyte solution within, and around, the aperture in which a particle is detected

[SOURCE:ISO 13319-1:2021, 3.3]

3.5.5

size bin

size interval to distinguish particle size for size distribution measurement

[SOURCE:ISO 13319-1:2021, 3.5]

3.5.6

envelope size

external size of a particle as seen in a microscope

[SOURCE:ISO 13319-1:2021, 3.6]

3.5.7

envelope volume

<electrical sensing zone methods> volume of the envelope given by the three-dimensional boundary of the particle to the surrounding medium

[SOURCE:ISO 13319-1:2021, 3.7, modified — domain has been included before the definition.]

3.6.1

absorption

<optics> reduction of intensity of a light beam not due to scattering

[SOURCE:ISO 13320:2020, 3.1.1]

3.6.2

complex refractive index

n_p

refractive index of a particle, consisting of a real and an imaginary (absorption) part

Note 2 to entry: In contrast to ISO 80000-7, this document follows the convention of adding a minus sign to the imaginary part of the refractive index.

Note 3 to entry: Imaginary (absorption) part can also represent conversion to other radiation loss of energy, see e.g. F A Jenkins H E White, Fundamentals of Optics, Third Edition; McGraw-Hill (1957), page 544

[SOURCE:ISO 13320:2020, 3.1.5, modified — note 3 has been added]

3.6.3

relative refractive index

m_rel

ratio of the complex refractive index of a particle to the real part of the dispersion medium

[SOURCE:ISO 24235:2007, 3.3, modified — “absolute refractive index” has been replaced by “complex refractive index” and “the sample” has been replaced by “a particle”.]

Note 1 to entry: In many applications, the medium is transparent and, thus, its refractive index has a negligible imaginary part.

[SOURCE:ISO 13320:2020, 3.1.19]

3.6.4

deconvolution

<laser diffraction particle size analysis> mathematical procedure whereby the size distribution of an ensemble of particles is inferred from measurements of their scattering pattern

[SOURCE:ISO 13320:2020, 3.1.6]

3.6.5

diffraction

<laser diffraction particle size analysis> scattering of light around the contour of a particle, observed at a substantial distance (in the ‘far field’)

[SOURCE:ISO 13320:2020, 3.1.7]

3.6.6

extinction

<laser diffraction particle size analysis> attenuation of a light beam traversing a medium through absorption and scattering

[SOURCE:ISO 13320:2020, 3.1.9]

3.6.7

intermediate precision

<laser diffraction particle size analysis > accuracy and precision under intermediate precision conditions (3.6.8)

[SOURCE:ISO 3534-2:2006, 3.3.15, modified — field of application <laser diffraction> has been added.]

3.6.8

intermediate precision conditions

<laser diffraction particle size analysis > conditions where test results or measurement results are obtained on different laser diffraction instruments and with different operators using the same prescribed method

Note 1 to entry: There are four elements to the operating condition: time, calibration, operator and equipment.

[SOURCE:ISO 13220:2020, 3.1.11]

3.6.9

multiple scattering

consecutive scattering of light by more than one particle, causing a scattering pattern that is no longer the sum of the patterns from all individual particles

[SOURCE:ISO 13320:2020, 3.1.12]

3.6.10

obscuration

fraction of incident light that is attenuated due to extinction (scattering and/or absorption) by particles

Note 1 to entry: Obscuration can be expressed as a percentage.

Note 2 to entry: When expressed as fractions, obscuration plus transmission (3.6.19) equal unity.

[SOURCE:ISO 13320:2020, 3.1.13]

3.6.11

optical model

theoretical model used for computing the model matrix for optically homogeneous and isotropic spheres with, if necessary, a specified complex refractive index

[SOURCE:ISO 13320:2020, 3.1.14]

3.6.12

reflection

<laser diffraction particle size analysis> change of direction of a light wave at a surface without a change in wavelength or frequency

[SOURCE:ISO 13320:2020, 3.1.17]

3.6.13

refraction

process by which the direction of a radiation is changed as a result of changes in its velocity of propagation in passing through an optically non-homogeneous medium, or in crossing a surface separating different media

[SOURCE:ISO 13320:2020, 3.1.18]

3.6.14

scattering

change in propagation of light at the interface of two media having different optical properties

[SOURCE:ISO 13320:2020, 3.1.23]

3.6.15

scattering angle

angle between the principal axis of the incident light beam and the scattered light

[SOURCE:ISO 13320:2020, 3.1.24]

3.6.16

scattering pattern

angular pattern of light intensity, I(θ ), or spatial pattern of light intensity, I(r), originating from scattering, or the related energy values taking into account the sensitivity and the geometry of the detector elements

[SOURCE:ISO 13320:2020, 3.1.25]

3.6.17

single scattering

scattering whereby the contribution of a single member of a particle population to the total scattering pattern remains independent of the other members of the population

[SOURCE:ISO 13320:2020, 3.1.26]

3.6.18

single shot

sample for an analysis, for which the entire content of a test sample container is used

[SOURCE:ISO 13320:2020, 3.1.27]

3.6.19

transmission

<laser diffraction particle size analysis> fraction of incident light that remains un-attenuated by the particles

Note 1 to entry: Transmission can be expressed as a percentage.

Note 2 to entry: When expressed as fractions, obscuration (3.6.10) plus transmission equal unity.

[SOURCE:ISO 13320:2020, 3.1.29]

3.7.1

average hydrodynamic diameter

hydrodynamic diameter (3.7.9) that reflects the central value of the underlying particle size distribution

Note 1 to entry: The average particle diameter is either directly determined without calculation of the particle size distribution, or calculated from the computed intensity-, volume- or number-weighted particle size distribution or from its fitted (transformed) density function. The exact nature of the average particle diameter depends on the evaluation algorithm.

Note 2 to entry: The cumulants method yields a scattered light intensity-weighted harmonic mean particle diameter, which is sometimes also referred to as the “z-average diameter.”

Note 3 to entry: Arithmetic, geometric and harmonic mean values can be calculated from the particle size distribution according to ISO 9276-2.

Note 4 to entry: Mean values calculated from density functions (linear abscissa) and transformed density functions (logarithmic abscissa) may significantly differ (ISO 9276-1).

Note 5 to entry: also depends on the particle shape and the scattering vector (and thus on the angle of observation, laser wavelength and refractive index of the suspension medium).

[SOURCE:ISO 22412:2017, 3.2]

3.7.2

polydispersity index

pi

dimensionless measure of the broadness of the size distribution

Note 1 to entry: The PI typically has values less than 0,07 for a monodisperse test sample of spherical particles..

[SOURCE:ISO 22412:2017, 3.3]

3.7.3

qualification

proof with reference material that an instrument is operating in agreement with its specifications

[SOURCE:ISO 22412:2017, 3.10]

3.7.4

scattering volume

volume defined by the intersection of the incident laser beam and the scattered light intercepted by the detector

[SOURCE:ISO 22412:2017, 3.4]

3.7.5

scattered intensity

intensity of the light scattered by the particles in the scattering volume

[SOURCE:ISO 22412:2017, 3.5]

3.7.6

validation

proof with reference material that a procedure is acceptable for all elements of its scope

Note 1 to entry: Evaluation of trueness requires a certified reference material (3.1.22) .

[SOURCE:ISO 22412:2017, 3.7]

3.7.7

count rate

photocurrent

I_s

number of photon pulses per unit time

Note 1 to entry: It is also a photodetector current which is proportional to the scattered intensity as measured by a detector.

[SOURCE:ISO 22412:2017, 3.6]

3.7.8

light scattering

change in propagation of light at the interface of two media having different optical properties

[SOURCE:ISO 13320:2009, 3.1.17]

3.7.9

hydrodynamic diameter

equivalent spherical diameter of a particle in a liquid having the same diffusion coefficient as the real particle in that liquid

[SOURCE:ISO/TS 80004‑6:2013, 3.2.6]

3.7.10

particle tracking analysis

PTA

method in which particles (3.1.1) undergoing Brownian and/or gravitational motion in a suspension are illuminated by a laser and the change in position of individual particles is used to determine particle size (3.1.9)

Note 1 to entry: Analysis of the time-dependent particle position yields translational diffusion coefficient and hence the particle size as hydrodynamic diameter (3.7.9) using the Stokes-Einstein relationship.

Note 2 to entry: The analysis is applicable to nanoparticles as the size of particles detected is typically in the range 10 nm to 2 000 nm. The lower limit requires particles with high refractive index and the upper limit is due to limited Brownian motion and sedimentation.

Note 3 to entry: Nanoparticle tracking analysis NTA is often used to describe PTA. NTA is a subset of PTA since PTA covers larger range of particle sizes than nanoscale (3.1.6) .

[SOURCE:ISO/TS 80004‑6:2021, 4.2.8, modified — Nanoparticle tracking analysis has been removed from the term, and Note 3 has been modified]

3.8.1

area equivalent diameter

diameter of a circle having the same area as the projected image of the particle

Note 1 to entry: It is also known as the Heywood diameter or as the equivalent circular diameter.

[SOURCE:ISO 13322-1:2014, 3.1.1]

3.8.2

binary image

digitized image consisting of an array of pixels, each of which has a value of 0 or 1, whose values are normally represented by dark and bright regions on the display screen or by the use of two distinct colours

[SOURCE:ISO 13322-1:2014, 3.1.2]

3.8.3

contrast (of an image

<image analysis particle size analysis> difference between the intensity of the particle image with respect to the background near to the particle

[SOURCE:ISO 13322-1:2014, 3.1.3]

3.8.4

edge detection

methods used to detect transition between objects and background

Note 1 to entry: See segmentation method (3.8.13)

[SOURCE:ISO 13322-1:2014, 3.1.4]

3.8.5

frame coverage

<dynamic image analysis> fraction of the image area that is obscured by the projection area of all segmented particles (3.1.1) counted in the image

Note 1 to entry: Frame coverage can be expressed as a part or percentage of image area.

[SOURCE:ISO 13322-2:2021, 3.1.5]

3.8.6

field of view

field which is viewed by the viewing device

3.9.1

border zone error

particle sizing error that occurs when particles pass through the optical border of the sensing zone

[SOURCE:ISO 21501-1:2009, 2.10]

3.9.2

coincidence error

probability of the presence of more than one particle inside the sensing zone simultaneously

Note 1 to entry: Coincidence error is related to particle number concentration, flow velocity through the sensing zone and size of sensing zone.

[SOURCE:ISO 27891:2015, 3.9]

3.9.3

counting efficiency

relation of the concentration determined from the counting rate of the measuring instrument and the real concentration of the aerosol at the inlet of the instrument

[SOURCE:ISO 21501-1:2009, 2.9]

3.9.4

light scattering equivalent particle diameter

x_sca

equivalent diameter of a homogeneous sphere of a reference substance (e.g. latex) which scatters defined incident light with the same radiation efficiency into a defined solid angle element

[SOURCE:ISO 21501-1:2009, 2.5]

3.9.5

number concentration distribution density

distribution density (frequency) of the particle number concentration represented as a function of the particle size

[SOURCE:ISO 21501-1:2009, 2.6, modified — the entry 'number concentration density distribution' has been modified to 'number concentration distribution density.]

3.9.6

particle concentration

ratio of particle quantity to the volume of the carrier gas or liquid

Note 1 to entry: Quantities can be particle number, surface, volume or mass

Note 2 to entry: For the exact concentration measurement in aerosols, information on the gaseous condition (temperature and pressure) or the reference to a standard volume is necessary.

[SOURCE:ISO 21501-1:2009, 2.7, modified — 'indication’ has been changed to ‘ratio’ and examples of quantity have been replaced by ‘quantity’ ]

3.9.7

calibration particles

monodisperse spherical particles with a known mean particle size, e.g. polystyrene latex (PSL) particles, where the certified size is traceable to the International System of Units (IS), a relative standard uncertainty equals to or less than 2,5 %, and a refractive index that is approximately 1,59 at the wave length of 589 nm (sodium D line)

Note 1 to entry: For spherical particles, the particle size is equal to the diameter.

[SOURCE:ISO 21501-2:2019, 3.1; ISO 21501-3:2019, 3.1; ISO 21501-4:2018, 3.1]

3.9.8

counting efficiency

<LSLPC> ratio of the number concentration measured by a light scattering liquid-borne particle counter (3.9.10) to that measured by a reference instrument for the same sample

[SOURCE:ISO 21501-2:2019, 3.2, modified — <LSLPC> has been added to show the domain.]

3.9.9

false count

<LSLPC> apparent count per unit volume of sample liquid when a sample liquid containing no measurable particles is measured by the light scattering liquid-borne particle counter (3.9.10)

[SOURCE:ISO 21501-2:2019, 3.3, modified — <LSLPC> has been added to show the domain.]

3.9.10

LSLPC

light scattering liquid-borne particle counter

instrument that measures liquid-borne particle numbers by counting the pulses as the particles pass through the sensing volume, as well as particle size by scattered light intensity

Note 1 to entry: The optical particle size measured by the LSLPC is the light scattering equivalent particle size and not the geometrical size.

[SOURCE:ISO 21501-2:2019, 3.4]

3.9.11

PHA

pulse height analyser

instrument that analyses the distribution of pulse heights

[SOURCE:ISO 21501-2:2019, 3.5; ISO 21501-3:2019, 3.4; ISO 21501-4:2018, 3.5]

3.9.12

size resolution

measure of the ability of an instrument to distinguish between particles of different sizes

[SOURCE:ISO 21501-2:2019, 3.6; ISO 21501-3:2019, 3.5; ISO 21501-4:2019, 3.6]

3.9.13

coincidence loss

reduction of particle count caused by multiple particles passing simultaneously through the sensing volume and/or by the finite processing time of the electronic system

[SOURCE:ISO 21501-2:2019, 3.7; ISO 21501-3:2019, 3.6; ISO 21501-4:2018, 3.7]

3.9.14

MPE

maximum permissible error

limit of error

extreme value of measurement error, with respect to a known reference quantity value, permitted by specifications or regulations for a given measurement, measuring instrument, or measuring system

Note 1 to entry: This document uses decimal numbers for the requirements to MPEs to avoid confusions that may arise when relative uncertainties of test results are reported in percent figures.

[SOURCE:ISO 21501-2:2019, 3.8; ISO 21501-3:2019, 3.8; ISO 21501-4:2018, 3.9]

3.9.15

LELPC counting efficiency

ratio of the particle number concentration measured by a light extinction liquid-borne particle counter (3.9.16) of a certified reference material (3.1.22) for particle number concentration to the certified value of the CRM

[SOURCE:ISO 21501-3:2019, 3.2, modified — <LELPC> has been added to show the domain.]

3.9.16

LELPC

light extinction liquid-borne particle counter

instrument that measures liquid-borne particle numbers by counting the pulses as the particles pass through the sensing volume, as well as particle size by the attenuation of light

Note 1 to entry: The optical particle size measured by the LELPC is the light extinction equivalent particle size and not the geometrical size.

[SOURCE:ISO 21501-3:2019, 3.3]

3.9.17

false count

<LSAPC> apparent count per unit volume when a sample air containing no measurable particles is measured by the light scattering airborne particle counter (LSAPC) (3.9.18)

[SOURCE:ISO 21501-4:2018, 3.3, modified — <LSAPC> has been added to show the domain.]

3.9.18

LSAPC

light scattering airborne particle counter

instrument that measures airborne particle numbers by counting the pulses as the particles pass through the sensing volume, and also particle size by scattered light intensity

Note 1 to entry: The optical particle size measured by the LSAPC is the light scattering equivalent particle size and not the geometrical size.

[SOURCE:ISO 21501-4:2018, 3.4]

3.9.19

test aerosol

aerosol to be used for calibration or testing of a light scattering airborne particle counter (LSAPC) (3.9.18) that is composed of calibration particles (3.9.7) suspended in clean air

[SOURCE:ISO 21501-4:2018, 3.8]

3.10.1

small angle X-ray scattering

method in which the elastically scattered intensity of X-rays is measured for small-angle deflections

Note 1 to entry: The scattering is typically measured in the angular range up to 5°. This provides structural information about inhomogeneities in materials with characteristic lengths typically ranging from 1 nm to 100 nm. Under certain conditions the limit of 100 nm can be significantly extended.

[SOURCE:ISO 18115-1:2013, 3.18, modified — Notes 2 and 3 to entry have been deleted.]

3.10.2

radius of gyration

R_g

square root of the ratio of the moment of inertia to the particle mass

Note 1 to entry: Guinier radius (i.e. radius of gyration) is expressed in nanometres. Typical average radii are in the range of 1 nm to 50 nm.

[SOURCE:ISO 17867:2020, 3.3]

3.11.1

clump

assemblage of particles which are either rigidly joined or loosely coherent

[SOURCE:ISO 14887:2000, 3.3]

3.11.2

critical micelle concentration

CMC

concentration of dispersing agent above which micelles will form

[SOURCE:ISO 14887:2000, 3.4]

3.11.3

Tyndall effect

light scattered perpendicular to a beam of light passing through a liquid that contains particles

[SOURCE:ISO 14887:2000, 3.8]

3.11.4

bias

estimate of a systematic measurement error

[SOURCE:ISO/IEC Guide 99:2007, 2.18]

3.11.5

error

measured quantity value minus a reference quantity value

Note 1 to entry: Errors may have a random or a systematic nature.

[SOURCE:ISO/IEC Guide 99:2007, 2.16]

3.11.6

grab sample

sample that has not been taken under well-defined conditions

[SOURCE:ISO 14488:2007, 3.5]

3.11.7

gross sample

primary sample, composed of several sample increments

[SOURCE:ISO 14488:2007, 3.4]

3.11.8

primary sample

sample (single or composed) taken from a defined bulk product

[SOURCE:ISO 14488:2007, 3.6]

3.11.9

representative sample

sample that has the same properties as a defined batch of material and represents the bulk material, within a defined confidence limit

[SOURCE:ISO 14488:2007, 3.7]

3.11.10

sample

part of a defined bulk product taken for the purpose of characterization

[SOURCE:ISO 14488:2007, 3.8]

3.11.11

sample increment

single sample, taken from any of a defined set of locations in a bulk product or at any of a defined set of times from a production/ transportation line, to be mixed with other increments to form a gross sample

[SOURCE:ISO 14488:2007, 3.9]

3.11.12

sampling sequence

sequence of sampling, sample division and combination steps that result in a test sample for a defined bulk product

[SOURCE:ISO 14488:2007, 3.10]

3.11.13

spot sample

sample, taken at a defined location or production time, from a batch of material

[SOURCE:ISO 14488:2007, 3.11]

3.11.14

test sample

sample that is entirely used for a property characterization

[SOURCE:ISO 14488:2007, 3.12]

3.11.15

hydrostatic balance

method to measure particle density based on particle dynamic sedimentation velocity with known fluid density and viscosity condition

[SOURCE:ISO/TS 14411‑1:2017, 3.1.4]

3.11.16

nominal value

designated diameter in terms of a target value in a given specification

Note 1 to entry: The nominal value is the target diameter for an individual picket as calculated from the upper and lower size of the picket fence distribution (3.11.17) , the number of pickets and the requirement of equal spacing of pickets on a lognormal scale. Actual values may differ from the nominal ones due to the availability of suitable material

[SOURCE:ISO/TS 14411-1:2017, 3.1.7]

3.11.17

picket fence distribution

mixture of several monodisperse particle fractions (pickets)

[SOURCE:ISO/TS 14411-1:2017, 3.1.8]

3.12.1

aerosol

system of solid and/or liquid particles suspended in gas

[SOURCE:ISO 15900:2020, 3.1; ISO 27891:2015, 3.1]

3.12.2

attachment coefficient

attachment probability of ions and aerosol particles

[SOURCE:ISO 15900:2020, 3.2]

3.12.3

condensation particle counter

CPC

instrument that measures the particle number concentration of an aerosol

Note 1 to entry: The sizes of particles detected are usually smaller than several hundred nanometres and larger than a few nanometres.

Note 2 to entry: A CPC is one possible detector for use with a DEMC.

Note 3 to entry: In some cases, a condensation particle counter may be called a condensation nucleus counter (CNC).

[SOURCE:ISO 15900:2020, 3.8]

3.12.4

critical mobility

instrument parameter of a DEMC that defines the electrical mobility of aerosol particles that exit the DEMC in aerosol form, which may be defined by the geometry, aerosol and sheath air flow rates, and electrical field intensity

Note 1 to entry: Particles larger or smaller than the critical mobility migrate to an electrode or exit with the excess flow and do not exit from the DEMC in aerosol form.

[SOURCE:ISO 15900:2020, 3.10]

3.12.5

differential electrical mobility classifier

DEMC

classifier that is able to select aerosol particles according to their electrical mobility and pass them to its exit

Note 1 to entry: A DEMC classifies aerosol particles by balancing the electrical force on each particle with its aerodynamic drag force in an electrical field. Classified particles are in a narrow range of electrical mobility determined by the operating conditions and physical dimensions of the DEMC, while they can have different sizes due to difference in the number of charges that they have.

[SOURCE:ISO 15900:2020, 3.11]

3.12.6

differential mobility analysing system

DMAS

system to measure the size distribution of submicrometre aerosol particles consisting of a charge conditioner, a DEMC, flow meters, a particle detector, interconnecting plumbing, a computer and suitable software

Note 1 to entry: Another common acronym for the DMAS is MPSS (mobility particle size spectrometer).

[SOURCE:ISO 15900:2020, 3.12]

3.12.7

electrical mobility

ratio of migration velocity (3.12.10) to electrical field for particles and ions in a gas

[SOURCE:ISO 15900:2020, 3.13]

3.12.8

Knudsen number

kn

ratio of gas molecular mean free path to the radius of the particle, which is an indicator of free molecular flow versus continuum gas flow

[SOURCE:ISO 15900:2020, 3.16]

3.12.9

laminar flow

gas flow with no temporally or spatially irregular activity or turbulent eddy flow

[SOURCE:ISO 15900:2020, 3.17; ISO 27891:2015, 3.20]

3.12.10

migration velocity

<aerosol particles> steady-state velocity of a charged airborne particle within an externally applied electric field

[SOURCE:ISO 15900:2020, 3.18]

3.12.11

Reynolds number

Re

dimensionless number expressed as the ratio of the inertial force to the viscous force

Note 1 to entry: For example, applied to an aerosol particle or a tube carrying aerosol particles

[SOURCE:ISO 15900:2020, 3.21]

3.12.12

slip correction

S_c

dimensionless factor that is used to correct the drag force acting on a particle for non-continuum effects that become important when the particle size is comparable to or smaller than the mean free path of the gas molecules

[SOURCE:ISO 15900:2020, 3.22]

3.12.13

Stokes' drag

drag force acting on a particle that is moving relative to a continuum fluid in the creeping flow limit (low Reynolds number)

[SOURCE:ISO 15900:2020, 3.23]

3.12.14

transfer function

ratio of particle concentration at the outlet of a DEMC to the particle concentration at the inlet of the DEMC

Note 1 to entry: It is normally expressed as a function of electrical mobility.

[SOURCE:ISO 15900:2020, 3.24]

3.12.15

electrometer

device that measures electrical current of about 1 femtoampere (fA) and higher

[SOURCE:ISO 27891:2015, 3.15]

3.12.16

Faraday-cup aerosol electrometer

FCAE

electrometer designed for the measurement of electrical charge concentration carried by an aerosol

Note 1 to entry: An FCAE consists of an electrically conducting and electrically grounded cup as a guard to cover the sensing element that includes aerosol filtering media to capture charged aerosol particles, an electrical connection between the sensing element and an electrometer circuit, and a flow meter. An FCAE measures electrical current ranging from about one femtoampere (fA) to about ten picoamperes (pA).

[SOURCE:ISO 15900:2020, 3.15]

3.12.17

calibration

operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties and, in a second step, uses this information to establish a relation for obtaining a measurement result from an indication

Note 1 to entry: A calibration may be expressed by a statement, calibration function, calibration diagram, calibration curve, or calibration table. In some cases, it may consist of an additive or multiplicative correction of the indication with associated measurement uncertainty.

Note 2 to entry: Calibration should not be confused with adjustment of a measuring system, often mistakenly called “self-calibration”, nor with verification of calibration.

Note 3 to entry: Often, the first step alone in the above definition is perceived as being calibration.

[SOURCE:ISO 27891:2015, 3.3]

3.12.18

calibration aerosol

charge conditioned and size classified primary aerosol with particle number concentration adjusted for the calibration measurement, as delivered by the flow splitter

[SOURCE:ISO 27891:2015, 3.4]

3.12.19

calibration particle material

material of the particles of the calibration aerosol

[SOURCE:ISO 27891:2015, 3.5]

3.12.20

detection efficiency

η

ratio of the concentration reported by an instrument to the actual concentration at the inlet of the instrument

[SOURCE:ISO 27891:2015, 3.11]

3.12.21

diffusion loss

reduction of particle number concentration due to thermal (or Brownian) and turbulent diffusion transport (e.g. to the walls of a transport tube)

[SOURCE:ISO 27891:2015, 3.14]

3.12.22

flow rate

quantity (volume or mass to be specified) of a fluid crossing the transverse plane of a flow path per unit time

Note 1 to entry: For the exact flow rate indication of gases, information on the gaseous condition (temperature and pressure) or the reference to a standard volume indication is necessary.

[SOURCE:ISO 27891:2015, 3.18]

3.12.23

GSD

acronym used in this International Standard for geometric standard deviation

[SOURCE:ISO 27891:2015, 3.19]

3.12.24

lower limit of the plateau efficiency

d_min,ref

lower size limit for which a reference CPC can be applied for the calibration of a test CPC

Note 1 to entry: This size limit depends on the CPC itself, but also to some extent on experimental conditions and on the particle type.

[SOURCE:ISO 27891:2015, 3.21]

3.12.25

monodisperse aerosol

aerosol with a narrow particle size distribution

Note 1 to entry: Monodispersity can be quantified by the geometric standard deviation (GSD) of the size distribution.

Note 2 to entry: In this International Standard, the term “monodisperse” is used for the GSD less than or equal to 1,15.

[SOURCE:ISO 27891:2015, 3.22]

3.12.26

particle number concentration

C

number of particles related to the unit volume of the carrier gas

Note 1 to entry: For the exact particle number concentration indication, information on the gaseous condition (temperature and pressure) or the reference to a standard volume indication is necessary.

[SOURCE:ISO 27891:2015, 3.25]

3.12.27

particle type

several particle properties like chemical composition of the particle material (especially chemical surface composition), physical particle shape and morphology (e.g. an agglomerate or aggregate)

Note 1 to entry: The CPC detection efficiency at low particle sizes will depend on the chemical affinity between the particle and the working fluid.

Note 2 to entry: Much of the underlying theory assumes that the particles are solid spheres. Non-sphericity can affect the size selection by the DEMC, the fraction of multiply charged particles, and the condensation of working fluid on the particle surface.

[SOURCE:ISO 27891:2015, 3.26]

3.12.28

plateau detection efficiency

mean detection efficiency of a CPC in the size range which is not biased by particle size

[SOURCE:ISO 15900:2020, 3.20]

3.12.29

primary aerosol

aerosol generated and conditioned in the primary aerosol source section of the calibration setup

[SOURCE:ISO 27891:2015, 3.28]

3.12.30

single particle counting mode

measurement mode of a particle number or number concentration measurement device (e.g. a CPC) in which every detected particle is counted to obtain the measurement result

[SOURCE:ISO 27891:2015, 3.29]

3.12.31

size distribution

distribution of particle concentration as a function of particle size

Note 1 to entry: In ISO 27891:2015, this term is used in the sense “particle number concentration represented as function of the particle diameter”.

Note 2 to entry: ISO 9276-1 can be applied for the representation of results of particle size distribution analysis.

[SOURCE:ISO 27891:2015, 3.30, modified — Note 1 has been adapted.]

3.12.32

turbulent flow

gas flow with temporally or spatially irregular activity or turbulent eddy flow

[SOURCE:ISO 27891:2015, 3.31]

3.13.1

charging

processes that leave aerosol particles with size dependent specific distributions of unipolar or bipolar electrical charges

[SOURCE:ISO 15900:2020, 3.5]

3.13.2

charge distribution function

mathematical and/or empirical description of a conditioned particle size dependent charge distribution

[SOURCE:ISO 15900:2020, 3.7]

3.13.3

conditioned charge distribution

distribution of unipolar or bipolar electrical charges on aerosol particles defined by a charge distribution function, which is in a steady state for a sufficiently long period of time in an aerosol instrument downstream of a unipolar or bipolar charge conditioner

[SOURCE:ISO 15900:2020, 3.9]

3.13.4

charge concentration

concentration of the net electrical charges per unit volume

Note 1 to entry: Charge concentration is the measurand of the FCAE.

[SOURCE:ISO 27891:2015, 3.6]

3.13.5

charge conditioning

process that establishes a steady state charge distribution on the sampled aerosol

[SOURCE:ISO 27891:2015, 3.7]

3.13.6

charge conditioner

device (or component of a DMAS) which establishes a known conditioned size dependent charge distribution on aerosol particles which are passed through it

[SOURCE:ISO 15900:2020, 3.6]

3.13.7

unipolar charger

particle charge conditioner that expose aerosol particles to either positive or negative ions within the device

[SOURCE:ISO 27891:2015, 3.32]

3.13.8

unipolar charge conditioner

device which attains a conditioned charge distribution of either positive or negative charges on aerosol particles

[SOURCE:ISO 15900:2020, 3.25]

3.13.9

unipolar charging

process which attains a conditioned charge distribution of positive or negative charges on aerosol particles

[SOURCE:ISO 15900:2020, 3.26]

3.13.10

bipolar charger

particle charge conditioner to attain the equilibrium, known size-dependent charge distribution by exposing aerosol particles to both positive and negative ions within the device

Note 1 to entry: Exposing aerosol particles to an electrically neutral cloud of positive and negative gas charges with sufficiently high charge concentration and for a sufficiently long period of time leads to an equilibrium with the net charge of the aerosol nearly zero (also known as charge neutralization).

[SOURCE:ISO 27891:2015, 3.2]

3.13.11

bipolar charging

process which attains a conditioned charge distribution of both positive and negative charges on aerosol particles

[SOURCE:ISO 15900:2020, 3.3]

3.13.12

bipolar charge conditioner

device which attains a conditioned charge distribution of both positive and negative charges on aerosol particles

[SOURCE:ISO 15900:2020, 3.4]

3.14.1

absorption

<ultrasonic particle size analysis> direct reduction of incident ultrasonic energy by means other than scattering

[SOURCE:ISO 20998-1:2006, 2.1]

3.14.2

attenuation

extinction

<ultrasonic particle size analysis> total reduction of incident ultrasonic energy, including both scattering and absorption

Note 1 to entry: The recommended measurement unit is the decibel (dB), which is defined as 10 times the common (base 10) logarithm of the ratio of incident intensity to transmitted intensity, or equivalently 20 times the common logarithm of the ratio of incident amplitude to transmitted amplitude. The Neper (Np) is a permitted alternative measurement unit based on the natural logarithm rather than the common logarithm. The conversion factor is 1 Np = 8,686 dB

[SOURCE:ISO 20998-1:2006, 2.2]

3.14.3

attenuation coefficient

extinction coefficient

attenuation (extinction) per unit length of ultrasonic propagation through a material, measured in units of dB/cm or Np/cm

Note 1 to entry: Attenuation coefficients are sometimes scaled by frequency, or frequency-squared, to identify the dominant attenuation mechanism. For clarity, in this part of ISO 20998, only the attenuation per unit length (in dB/cm) is considered.

[SOURCE:ISO 20998-1:2006, 2.3]

3.14.4

attenuation spectrum

attenuation coefficient measured as a function of frequency

[SOURCE:ISO 20998-1:2006, 2.4]

3.14.5

bandwidth

range of frequencies contained in an ultrasonic signal, typically measured as the frequency difference between the -3 dB points on a spectrum analyzer

[SOURCE:ISO 20998-1:2006, 2.5]

3.14.6

broadband

characterized as having a bandwidth that is equal to at least half of the centre frequency

[SOURCE:ISO 20998-1:2006, 2.6]

3.14.7

digitisation

act of generating a digital (quantized) representation of a continuous signal

Note 1 to entry: The number of bits determines the resolution (fidelity), and the sampling rate determines the bandwidth (Nyquist criterion).

[SOURCE:ISO 20998-1:2006, 2.7]

3.14.8

excess attenuation

incremental attenuation caused by the presence of particles in the continuous phase

[SOURCE:ISO 20998-1:2006, 2.8]

3.14.9

Fourier transform

mathematical transform that converts a time-varying signal into its frequency components, which is often implemented in computers as a Fast Fourier Transform (FFT) algorithm

[SOURCE:ISO 20998-1:2006, 2.9]

3.14.10

interference

wave phenomenon of cancellation or enhancement observed when two or more waves overlap

[SOURCE:ISO 20998-1:2006, 2.10]

3.14.11

intrinsic response

frequency-dependent response of the ultrasonic spectrometer itself

Note 1 to entry: This is not to be confused with the intrinsic absorption of the sample component materials.

[SOURCE:ISO 20998-1:2006, 2.11]

3.14.12

path length

distance traversed by the ultrasonic wave between the emitting transducer and the receiver

[SOURCE:ISO 20998-1:2006, 2.12]

3.14.13

pulse

wave of sufficiently short duration to contain broadband Fourier components

[SOURCE:ISO 20998-1:2006, 2.13]

3.14.14

reflection

<ultrasonic particle size analysis> return of an ultrasonic wave at an interface or surface

[SOURCE:ISO 20998-1:2006, 2.14]

3.14.15

scattering

<ultrasonic particle size analysis> removal of ultrasonic energy from the incident wave by redirection

[SOURCE:ISO 20998-1:2006, 2.15]

3.14.16

spectrum

frequency components of a signal, typically arranged as magnitude versus frequency

[SOURCE:ISO 20998-1:2006, 2.16]

3.14.17

tone-burst

short duration of a few cycles of a sinusoidal wave

Note 1 to entry: Typically, a tone burst consists of 5 to 10 cycles of a sinusoidal wave.

[SOURCE:ISO 20998-1:2006, 2.17]

3.14.18

transducer

device for generating ultrasound from an electrical signal or vice versa

Note 1 to entry: Piezoelectric devices are commonly used for this purpose.

[SOURCE:ISO 20998-1:2006, 2.18]

3.14.19

transmission

<ultrasonic particle size analysis> passage of ultrasound through a sample

[SOURCE:ISO 20998-1:2006, 2.19]

3.14.20

transmission spectrum

the transmission value measured as a function of frequency

[SOURCE:ISO 20998-1:2006, 2.20]

3.14.21

transmission value

amplitude of an ultrasonic signal (or a component thereof) that has been transmitted through a sample; measured in Volts or arbitrary units

[SOURCE:ISO 20998-1:2006, 2.21]

3.14.22

ultrasound

high frequency (over 20 kHz) sound waves which propagate through fluids and solids

Note 1 to entry: The range employed in particle characterization is typically 100 kHz to 100 MHz.

[SOURCE:ISO 20998-1:2006, 2.22]

3.14.23

wave

a fluctuation (e.g. pressure, shear, or thermal) that propagates through a physical medium

[SOURCE:ISO 20998-1:2006, 2.23]

3.14.24

waveform

shape of the wave when seen on an oscilloscope or digitized display

[SOURCE:ISO 20998-1:2006, 2.24]

3.14.25

wavelength

length of a wave, determined by the distance between corresponding points on successive waves

[SOURCE:ISO 20998-1:2006, 2.25]

3.14.26

dimensionless size parameter

representation of particle size as the product of wave number (3.14.27) and particle radius

[SOURCE:ISO 20998-2:2013, 3.2]

3.14.27

wave number

ratio of 2π to the wavelength

[SOURCE:ISO 20998-2:2013, 3.4]

3.15.1

focused beam reflectance method

method whose probe uses a focused light beam passing particles in a suspension or aerosol and which measures a chord length distribution (CLD) different from a particle size distribution (PSD)

Note 1 to entry: In order to compare results obtained by an FBRM probe with other measurement technologies such as laser diffraction, it is necessary to reconstruct the PSD from a measured CLD.

3.16.1

agglomerate

<particle dispersion in liquids> loosely coherent assembly of particles (3.1.1) and/or aggregates (3.1.3) held together by weak physical interactions, with a total surface area virtually equal to the sum of the surface areas of the constituent particles (3.1.5)

Note 1 to entry: The transitive verb “agglomerate” means “to gather into a cluster”, and the process by which the cluster or assembly is formed is generally called “agglomeration”.

Note 2 to entry: Agglomeration can be a reversible process.

[SOURCE:ISO/TS 22107:2021, 3.1, modified — domain has been included before the definition]

3.16.2

aggregate

<particle dispersion in liquids> assemblage of particles (3.1.1) into rigidly joined structures

Note 1 to entry: Formation of aggregates is usually an irreversible process..

Note 2 to entry: The forces holding an aggregate together are strong, for example covalent bonds or those resulting from sintering or complex physical entanglement.

Note 3 to entry: In common use, the terms aggregate and agglomerate (also aggregation and agglomeration) are sometimes applied interchangeably, but this practice is deprecated since the terms are not synonymous.

Note 4 to entry: The transitive verb “aggregate” means “to gather into a mass or whole”, and the process by which the structure is formed is generally called “aggregation”.

[SOURCE:ISO/TS 22107:2021, 3.2, modified — domain has been included before the definition]

3.16.3

coalescence

disappearance of the boundary between two particles (usually droplets or bubbles) in contact, or between one of these and a bulk phase followed by changes of shape leading to a reduction of the total surface area

Note 1 to entry: The flocculation of an emulsion, namely the formation of aggregates, may be followed by coalescence.

[SOURCE:IUPAC Gold Book^[1]]

3.16.4

creaming

rise (separation) of the dispersed phase in an emulsion due to the lower density of the dispersed phase (droplets) compared to the continuous phase

Note 1 to entry: Creaming velocity has a negative sign as particle movement is opposite to the acting force.

[SOURCE:ISO/TR 13097:2013, 2.4]

3.16.5

dispersion

multi-phase system in which discontinuities of any state (solid, liquid or gas) are homogeneously distributed in a continuous phase of a different composition or state

Note 1 to entry: This term can also refer to the act or process of producing a dispersion, but in this context the term “dispersion process” should be used.

Note 2 to entry: If solid particles are dispersed in a liquid, the dispersion is referred to as a suspension. If the dispersion consists of two or more immiscible liquid phases, it is termed an emulsion.

[SOURCE:ISO/TS 22107:2021, 3.7]

3.16.6

dispersion stability

ability to resist change or variation in the initial properties (state) of a dispersion over time, in other words, the quality of a dispersion in being free from alterations over a given time scale

Note 1 to entry: In this context, e.g. agglomeration or segregation represents a loss of dispersion stability.

[SOURCE:ISO/TS 22107:2021, 3.8]

3.16.7

flocculation

assembly of particles in a dispersed system into loosely coherent structures that are held together by weak physical interactions

Note 1 to entry: The term flocculation has been frequently used to denote agglomeration facilitated by addition of a flocculating agent (e.g., a polyelectrolyte).

Note 2 to entry: See agglomeration (3.16.1) .

[SOURCE:ISO/TR 13097:2013, 2.7]

3.16.8

flotation

migration of a dispersed solid phase to the top of a liquid continuous phase, when the effective particle density is lower relative to the continuous phase density

Note 1 to entry: It may be facilitated by adhering gas bubbles, for example dissolved air flotation, or the application of lipophilic surfactants (e.g., in ore processing).

[SOURCE:ISO/TR 13097:2013, 2.8]

3.16.9

Ostwald ripening

dissolution of small particles and the redeposition of the dissolved species on the surfaces of larger particles

Note 1 to entry: The process occurs because smaller particles have a higher surface energy, hence higher total Gibbs energy, than larger particles, giving rise to an apparent higher solubility.

[SOURCE:IUPAC Gold Book^[1]]

3.16.10

phase inversion

phenomenon whereby the phases of a liquid-liquid dispersion (emulsion) interchange such that the dispersed phases spontaneously inverts to become the continuous phase, and vice versa, under conditions determined by the system properties, volume ratio and energy input

[SOURCE:Yeo et al.^[3]]

3.16.11

phase separation

process by which a macroscopically homogeneous suspension, emulsion or foam separates into two or more new phases

[SOURCE:Yeo et al.^[3]]

3.16.12

shelf life

recommended time period during which a product (dispersions) can be stored, throughout which the defined quality of a specified property of the product remains acceptable under expected (or specified) conditions of distribution, storage, display and usage

[SOURCE:Gyeszly^[4]]

3.16.13

comminution

operation of reducing particle size by crushing, grinding or pulverisation

[SOURCE:ISO/TS 22107:2021, 3.3]

3.16.14

dispersant

substance capable of promoting the formation of a dispersion

Note 1 to entry: Also called a dispersing agent (e.g. wetting agent or surfactant)

[SOURCE:ISO/TS 22107:2021, 3.4]

3.16.15

disperse

distribute particles homogeneously throughout a continuous phase, often by means of reducing the size of agglomerates

Note 1 to entry: Also called a dispersing agent (e.g. wetting agent or surfactant)

[SOURCE:ISO/TS 22107:2021, 3.5]

3.16.16

dispersibility

qualitative or quantitative characteristic or property of a particulate source material assessing the ease with which said material can be dispersed within a continuous phase

Note 1 to entry: Spatially uniform distribution (homogeneity) of the dispersed phase is considered an integral part of the desired end point.

Note 2 to entry: Particle size or particle size distribution is often used as an end point relative to defined criteria specific to the application.

Note 3 to entry: Dispersibility refers to a specific dispersion process and specific process time.

Note 4 to entry: Dispersion stability, though a related phenomenon, should not be confused with dispersibility.

[SOURCE:ISO/TS 22107:2021, 3.6]

3.16.17

energy density

amount of energy per unit volume of sample applied to a material

[SOURCE:ISO/TS 22107:2021, 3.9]

3.16.18

floc

ensemble of particles that form a loosely coherent structure with high void fraction

Note 1 to entry: Flocs are held together by weak particle-particle attraction or by the osmotic pressure of a continuous phase containing polymers not adsorbing to dispersed particles (loss of configurational entropy of polymers, depletion flocculation).

Note 2 to entry: The term floc may be used to denote an agglomerate produced by addition of a flocculating agent (e.g., a polyelectrolyte), but flocs can also form spontaneously.

[SOURCE:adapted from ISO 862:1984]

3.17.1

Electric double layer

Note 1 to entry: The electric double layer (EDL) is a spatial distribution of electric charges that appears on and at the vicinity of the surface of an object when it is placed in contact with a liquid.

3.17.2

Debye–Hückel approximation

model assuming small electric potentials in the electric double layer

[SOURCE:ISO 13099-1:2012, 2.1.1; ISO 13099-3:2014, 3.1.1]

3.17.3

Debye length

κ⁻¹

characteristic length of the electric double layer in an electrolyte solution

Note 1 to entry: The Debye length is expressed in nanometres.

[SOURCE:ISO 13099-1:2012, 2.1.2; ISO 13099-3:2014, 3.1.2]

3.17.4

diffusion coefficient

D

mean squared displacement of a particle per unit time

Note 1 to entry: The diffusion coefficient is expressed in metre squared per second.

[SOURCE:ISO 13099-1:2012, 2.1.3 without Note 1; ISO 13099-3:2014, 3.1.3 with Note 1]

3.17.5

Dukhin number

Du

dimensionless number which characterizes the contribution of the surface conductivity in electrokinetic and electroacoustic phenomena, as well as in conductivity and dielectric permittivity of heterogeneous systems

[SOURCE:ISO 13099-1:2012, 2.1.4; ISO 13099-3:2014, 3.1.4]

3.17.6

dynamic viscosity

η

<methods for zeta potential determination> ratio between the applied shear stress and the rate of shear of a liquid

Note 1 to entry: For the purposes of this part of ISO 13099, dynamic viscosity is used as a measure of the resistance of a fluid which is being deformed by shear stress.

Note 2 to entry: Dynamic viscosity determines the dynamics of an incompressible Newtonian fluid.

Note 3 to entry: Dynamic viscosity is expressed in pascal seconds.

[SOURCE:ISO 13099-1:2012, 2.1.5; ISO 13099-3:2014, 3.1.5, modified — domain has been added]

3.17.7

electric surface charge density

σ

charges on an interface per area due to specific adsorption of ions from the liquid bulk, or due to dissociation of the surface groups

Note 1 to entry: Electric surface charge density is expressed in coulombs per square metre.

[SOURCE:ISO 13099-1:2012, 2.1.6; ISO 13099-3:2014, 3.1.6]

3.17.8

electric surface potential

ψ^s

difference in electric potential between the surface and the bulk liquid

Note 1 to entry: Electric surface potential is expressed in volts.

[SOURCE:ISO 13099-1:2012, 2.19.; ISO 13099-2:2012, 3.1.3; ISO 13099-3:2014, 3.19.]

3.17.9

zeta-potential

ζ-potential

ζ

difference in electric potential between that at the slipping plane and that of the bulk liquid

Note 1 to entry: Electrokinetic potential is expressed in volts.

[SOURCE:ISO 13099-1:2012, 2.1.8; ISO 13099-2:2012, 3.1.4; ISO 13099-3:2014, 3.1.8]

3.17.10

Gouy–Chapman–Stern model

model describing the electric double layer

[SOURCE:ISO 13099-1:2012, 2.1.9; ISO 13099-3:2014, 3.1.9]

3.17.11

isoelectric point

condition of liquid medium, usually the value of pH, that corresponds to zero zeta-potential of dispersed particles

[SOURCE:ISO 13099-1:2012, 2.1.10; ISO 13099-3:2014, 3.1.10]

3.17.12

slipping plane

shear plane

abstract plane in the vicinity of the liquid/solid interface at which liquid starts to slide relative to the surface under influence of a shear stress

[SOURCE:ISO 13099-1:2012, 2.1.11; ISO 13099-2:2012, 3.1.9; ISO 13099-3:2014, 3.1.11]

3.17.13

Stern potential

ψ^d

electric potential on the external boundary of the layer of specifically adsorbed ions

Note 1 to entry: Stern potential is expressed in volts.

[SOURCE:ISO 13099-1:2012, 2.1.12; ISO 13099-3:2014, 3.1.12]

3.17.14

Brownian motion

Random movement of particles suspended in a liquid caused by the thermal movement of the medium molecules

[SOURCE:ISO 13099-2:2012, 3.1.1]

3.17.15

Doppler shift

change in frequency and wavelength of a wave for an observer moving relative to the source of the wave

[SOURCE:ISO 13099-2:2012, 3.1.2]

3.17.16

Electrokinetic phenomena

Note 1 to entry: Electrokinetic phenomena are associated with tangential liquid motion adjacent to a charged surface.

3.17.17

electroosmosis

motion of liquid through or past a charged surface, e.g. an immobilized set of particles, a porous plug, a capillary or a membrane, in response to an applied electric field, which is the result of the force exerted by the applied field on the countercharge ions in the liquid

[SOURCE:ISO 13099-1:2012, 2.2.1; ISO 13099-2:2012, 3.1.5; ISO 13099-3:2014, 3.2.1]

3.17.18

electroosmotic counter-pressure

Δp_eo

pressure difference that is applied across the system to stop the electroosmotic flow

Note 1 to entry: The electroosmotic counter-pressure value is positive if the high pressure is on the higher electric potential side.

Note 2 to entry: Electroosmotic counter-pressure is expressed in pascals.

[SOURCE:ISO 13099-1:2012, 2.2.2; ISO 13099-3:2014, 3.2.2]

3.17.19

electroosmotic velocity

υ_eo

uniform velocity of the liquid far from the charged interface

Note 1 to entry: Electroosmotic velocity is expressed in metres per second.

[SOURCE:ISO 13099-1:2012, 2.2.3; ISO 133099-2, 3.1.6; ISO 133099-3:2014, 3.2.3]

3.17.20

electrophoresis

movement of charged colloidal particles or polyelectrolytes, immersed in a liquid, under the influence of an external electric field

[SOURCE:ISO 13099-1:2012, 2.2.4; ISO 13099-3:2014, 3.2.4]

3.17.21

electrophoretic mobility

μ_e

electrophoretic velocity per electric field strength

Note 1 to entry: Electrophoretic mobility is positive if the particles move toward lower potential (negative electrode) and negative in the opposite case.

Note 2 to entry: Electrophoretic mobility is expressed in metres squared per volt second.

[SOURCE:ISO 13099-1:2012, 2.2.5; ISO 13099-2:2012, 3.1.7; ISO 13099-3:2014, 3.2.5]

3.17.22

electrophoretic velocity

υ_e

particle velocity during electrophoresis

Note 1 to entry: Electrophoretic velocity is expressed in metres per second.

[SOURCE:ISO 13099-1:2012, 2.2.6; ISO 13099-2:2012, 3.1.8; ISO 13099-3:2014, 3.2.6]

3.17.23

sedimentation potential

U_sed

potential difference sensed by two electrodes placed some vertical distance apart in a suspension in which particles are sedimenting under the effect of gravity

Note 1 to entry: When the sedimentation is produced by a centrifugal field, the phenomenon is called centrifugation potential.

Note 2 to entry: Sedimentation potential is expressed in volts.

[SOURCE:ISO 13099-1:2012, 2.2.19.; ISO 13099-3:2014, 3.2.7]

3.17.24

streaming current

I_str

current through a porous body resulting from the motion of fluid under an applied pressure gradient

Note 1 to entry: Streaming current is expressed in amperes.

[SOURCE:ISO 13099-1:2012, 2.2.8; ISO 13099-3:2014, 3.2.8]

3.17.25

streaming current density

J_str

streaming current per area

Note 1 to entry: Streaming current density is expressed in amperes per square metre.

[SOURCE:ISO 13099-1:2012, 2.2.9; ISO 13099-3:2014, 3.2.9]

3.17.26

streaming potential

U_str

potential difference at zero electric current, caused by the flow of liquid under a pressure gradient through a capillary, plug, diaphragm or membrane

Note 1 to entry: Streaming potentials are created by charge accumulation caused by the flow of countercharges inside capillaries or pores.

Note 2 to entry: Streaming potential is expressed in volts.

[SOURCE:ISO 13099-1:2012, 2.2.10; ISO 13099-3:2014, 3.2.10]

3.17.27

surface conductivity

K^σ

excess electrical conduction tangential to a charged surface

Note 1 to entry: Surface conductivity is expressed in siemens.

[SOURCE:ISO 13099-1:2012, 2.2.11; ISO 13099-3:2014, 3.2.11]

3.17.28

Electroacoustic phenomena

Note 1 to entry: Electroacoustic phenomena arise from the coupling between the ultrasound field and electric field in a liquid that contains ions. Either of these fields can be primary driving force. Liquid might be a simple Newtonian liquid or complex heterogeneous dispersion, emulsion or even a porous body. There are several different electroacoustic effects, depending on the nature of the liquid and type of the driving force.

3.17.29

colloid vibration current

CVI

I_CVI

a.c. current generated between two electrodes, placed in a dispersion, if the latter is subjected to an ultrasonic field

Note 1 to entry: Colloid vibration current is expressed in amperes.

[SOURCE:ISO 13099-1:2012, 2.3.1; ISO 13099-3:2014, 3.3.1, modified — Note 1 to entry appears in ISO 13099-3:2014 but not in ISO 13099-1.]

3.17.30

colloid vibration potential

CVU

a.c. potential difference generated between two electrodes, placed in a dispersion, if the latter is subjected to an ultrasonic field

Note 1 to entry: Colloid vibration potential is expressed in volts.

[SOURCE:ISO 13099-1:2012, 2.3.2; ISO 13099-3:2014, 3.3.2]

3.17.31

electrokinetic sonic amplitude

ESA

A_ESA

amplitude is created by an a.c. electric field in a dispersion with electric field strength, E; it is the counterpart of the colloid vibration potential method

Note 1 to entry: See Reference [5], [11] and [12].

Note 2 to entry: Electrokinetic sonic amplitude is expressed in pascals.

[SOURCE:ISO 13099-1:2012, 2.3.3; ISO 13099-3:2014, 3.3.3, modified — Note 1 of ISO 13099-1:2012 refers [5] while Note 1 of ISO 13099-3:2014 refers to [11,12]^.]

3.17.32

ion vibration current

IVI

a.c. electric current created from different displacement amplitudes in an ultrasound wave due to the difference in the effective mass or friction coefficient between anion and cation

Note 1 to entry: See References [6][7].

Note 2 to entry: Ion vibration current is expressed in amperes.

[SOURCE:ISO 13099-1:2012, 2.3.4; ISO 13099-3:2014, 3.3.4, modified — Note 1 in ISO 13099-1:2012 refers [6,7]while Note 1 of ISO 13099-3:2014 refers only[6].]

3.17.33

streaming vibration current

SVI

streaming current that arises in a porous body when ultrasound wave propagates through it

Note 1 to entry: See References [8][9].

Note 2 to entry: A similar effect can be observed at a non-porous surface, when sound is bounced off at an oblique angle, see Reference [10].

Note 3 to entry: Streaming vibration current is expressed in amperes.

[SOURCE:ISO 13099-1:2012, 2.3.5]

3.17.34

seismoelectric effect

SEI

non-isochoric streaming current that arises in a porous body when an ultrasound wave propagates through

Note 1 to entry: See References [13] and [14].

Note 2 to entry: A similar effect can be observed at a non-porous surface, when sound is bounced off at an oblique angle ^[15].

Note 3 to entry: Seismoelectric effect is expressed in amperes.

[SOURCE:ISO 13099-3:2014, 3.3.5]

3.17.35

electroseismic effect

ESI

non-isochoric electroosmotic pressure wave that arises in a porous body under the influence of a high frequency electric field

Note 1 to entry: See References [13] and [14].

Note 2 to entry: Electroseismic effect is expressed in pascals.

[SOURCE:ISO 13099-3:2014, 3.3.6]

3.17.36

dynamic electrophoretic mobility

μ_d

the electrophoretic velocity per unit electric field strength in a high frequency (MHz) electric field

Note 1 to entry: Traditional electrophoretic mobility is a low frequency asymptote of dynamic electrophoretic mobility.

Note 2 to entry: Electrophoretic mobility is expressed in metres squared per volt second.

[SOURCE:ISO 13099-3:2014, 3.3.7]