ISO 25178-602:2010 幾何学的製品仕様（GPS）—表面テクスチャ：面積—パート602：非接触（共焦点クロマチックプローブ）機器の公称特性 | ページ 6

3.1.1

計器の座標系

注記 1通常、X 軸がトレース軸で、Y 軸がステップ軸です。

3.1.2

測定ループ

ワークピースと クロマチックプローブ（3.3.2） を接続するすべてのコンポーネントを含むクローズドチェーン。たとえば、位置決め手段、ワーク保持治具、測定スタンド、 駆動ユニット（3.2.3および3.2.4） 、および プロービングシステム（ 3.3.1)

注記 1:測定ループは、測定の不確かさに影響を与える外部および内部の妨害を受ける。

図 1 —計器の座標系と測定ループ

Key

1	計器の座標系
2	測定ループ

3.1.3

ワークピースの実表面

物理的に存在し、ワークピース全体を周囲の媒体から分離する機能のセット

[出典:ISO 14660-1:1999, 定義 2.4]

3.1.4

実電磁面

ワークピースの実際の表面との電磁相互作用によって得られる表面

[出典:ISO 14406: — ¹⁾ 、定義 3.2.2]

注記 1: ISO 25178 のこのパートで説明されている機器について考慮される実際の電磁表面は、他のタイプの光学機器の実際の電磁表面とは異なる場合があります。

3.1.5

一次抽出面

プライマリ サーフェスからサンプリングされたデータ ポイントの有限セット

[出典:ISO 14406: — ¹⁾ 、定義 3.7]

3.1.6

測定誤差

測定誤差

エラー

測定量値から参照量値を差し引いた値

注記 2:測定誤差を製造上の誤差または間違いと混同してはなりません。

[出典:ISO/IEC Guide 99:2007, 定義 2.16]

3.1.7

系統測定誤差

測定の系統誤差

系統誤差

測定誤差（3.1.6） の成分で，反復測定において一定のままであるか，又は予測可能な方法で変化するもの。

注記1系統的測定誤差の参照量値は，真の量値，測定不確かさを無視できる測定標準の測定量値，又は従来の量値である。

注記2体系的な測定誤差とその原因は、既知または未知の場合があります。 補正 (3.1.11) を適用して、既知の系統的測定誤差を補正することができます。

注記3系統的測定誤差は，測定誤差からランダム 測定誤差を差し引いたものに等しい（3.1.8） 。

[出典:ISO/IEC Guide 99:2007, 定義 2.17]

3.1.8

ランダム測定誤差

ランダムな測定誤差

ランダムエラー

測定誤差（3.1.6） の構成要素であって，反復測定において予測できない方法で変動するもの。

注記1ランダム測定誤差の参照量値は，同じ測定量の無限回の反復測定から生じる平均値である。

注記2一連の反復測定のランダム測定誤差は，一般にゼロと仮定されるその期待値とその分散によって要約できる分布を形成する。

注記3ランダム測定誤差は，測定誤差から 系統的測定誤差を差し引いたものに等しい(3.1.7) 。

[出典:ISO/IEC Guide 99:2007, 定義 2.19]

3.1.9

測定器の調整

調整

測定される量の与えられた値に対応する所定の指示を提供するために測定システムで実行される一連の操作

注記1測定系の調整の種類には，測定系のゼロ調整，オフセット調整，スパン調整（ゲイン調整と呼ばれることもある）がある。

注記2測定システムの調整を、調整の前提条件である校正と混同してはならない。

注記3測定システムの調整後、通常、測定システムを再校正する必要があります。

[出典:ISO/IEC Guide 99:2007, 定義 3.11]

注記 4:これは，通常はユーザーが持っていない特殊な装置と知識を必要とするため，機器の製造業者によって通常行われる操作である。

3.1.10

ユーザー調整

使用者が自由に使用できる手段のみを使用 する測定器（3.1.9）の調整。

注記 1:これは通常、ユーザーによって実行される操作です。これには、通常、機器に付属している測定標準の使用が含まれます。この操作の結果、装置が正しく動作するように特定のパラメータが自動または手動で調整されます。

3.1.11

修正

推定された系統的効果の補償

注記 1: 「系統的影響」の説明については、ISO/IEC Guide 98-3:2008, 定義 3.2.3 を参照してください。

注記2補数は加数や因数などのさまざまな形式をとるか、表から推定することができます。

[出典:ISO/IEC Guide 99:2007, 定義 2.53]

3.1.12

残留補正誤差

系統的測定誤差（3.1.7） を補正した後に得られる量の値とこの量の実際の値との差。

注記1残留誤差は， ランダム誤差(3.1.8) と未補正の系統誤差から構成される。

3.2.1

lateral scanning system

system that performs the scanning of the surface to be measured in the (X,Y) plane

Note 1 to entry: Typically, the lateral scanning system is composed of the drive unit X (3.2.3) and the drive unit Y (3.2.4) .

3.2.2

areal reference guide

component of the instrument that generates the reference surface in which the probing system (3.3.1) moves relative to the surface being measured according to a theoretically exact trajectory

Note 1 to entry: In the case of areal surface texture measurement instruments, the reference guide establishes a reference surface (see ISO 25178-2). It can be achieved through the use of two perpendicular reference guides (see ISO 3274:1996, 3.3.2) or one reference surface guide.

3.2.3

drive unit X

component of the instrument that moves the probing system (3.3.1) or the surface being measured along the reference guide on the X-axis and returns the horizontal position of the measured point in terms of lateral X coordinate of the profile

3.2.4

drive unit Y

component of the instrument that moves the probing system or the surface being measured along the reference guide on the Y-axis and returns the horizontal position of the measured point in terms of lateral Y coordinate of the profile

3.2.5

lateral position sensor

component of the drive unit that provides the lateral position of the measured point

Note 1 to entry: The lateral position can be measured or inferred by using, for example, a linear encoder, a laser interferometer, or a counting device coupled with a micrometer screw.

3.3.1

probing system

components of the instrument called confocal chromatic probe, consisting of an optoelectronic controller, a fibre optic cable and a confocal chromatic objective

3.3.2

chromatic probe

device that converts the height of a point on the surface into a signal during measurement, using the confocal chromatic dispersion of a white light source

Note 1 to entry: Chromatic dispersion can be realized by using various optic configurations (see Annex B).

3.3.3

angular aperture

angle of the cone of light entering an optical system from a point on the surface being measured

3.3.4

half aperture angle

α

one half of the angular aperture (3.3.3)

Note 1 to entry: This angle is sometimes also called the half cone angle.

Figure 2—Half aperture angle

Key

L	lens or optical system
P	focal point
α	half aperture angle

3.3.5

numerical aperture

A_N

Note 1 to entry: In air, n approximately equals 1 and can be omitted from the equation.

Note 2 to entry: For a chromatic probe (3.3.2) , the numerical aperture is dependent on the wavelength of light. Typically the numerical aperture is specified for the wavelength focused at the middle of the vertical range (3.3.14) .

3.3.6

confocal chromatic microscopy

surface topography measurement method consisting of a confocal microscope with chromatic objective integrated with a detection device (e.g. spectrometer) whereby the surface height at a single point is sensed by the wavelength of light reflected from the surface

[SOURCE:ISO 25178-6:2010, 3.3.7]

3.3.7

achromatic objective

objective that produces a single focus for all wavelengths of the transmitted light

3.3.8

objective with axial chromatic dispersion

objective that produces a different focus along its optical axis for each wavelength of the transmitted light

3.3.9

light source

source of light containing a continuum of wavelengths in a predefined spectral region

Note 1 to entry: The spectral region emitted by the source should be compatible with the spectral bandwidth of the detector.

Note 2 to entry: Typically, this spectral region extends from wavelength values of 0,4 µm to 0,8 µm.

3.3.10

light source pinhole

small hole placed following the light source (3.3.9) , transforming the light source into a point light source

Note 1 to entry: See notes in 3.3.11.

3.3.11

discrimination pinhole

small hole placed in front of the detector, providing depth discrimination on a beam reflected from the sample surface by blocking defocused light

Note 1 to entry: The system contains two pinholes: the first one is the light source pinhole (3.3.10) . It defines a small spot of light that acts as the point light source for the instrument. The second one is the discrimination pinhole. It limits the transmitted beam to the part that is in focus on the sample surface and is reflected by it along the optical axis (see Figure B.1).

Note 2 to entry: In practice, the pinholes are obtained by using a fibre optic which provides spatial discrimination and allows the optical head to be used away from the optoelectronic controller.

3.3.12

chromatic depth of field

distance between the focal point of the shortest wavelength and the focal point of the longest wavelength of the spectral continuum emitted by the source

Note 1 to entry: This definition differs from the typical definition for depth of field used in other optical systems, such as a conventional microscope.

3.3.13

working distance

distance measured along the optical axis between the element closest to the surface and the point on the surface located in the middle of the vertical range (3.3.14)

3.3.14

vertical range

distance measured between the focal point of the shortest wavelength and the focal point of the longest wavelength detected on the spectrometer

Note 1 to entry: The vertical range depends on the chromatic depth of field (3.3.12) and on the spectral range of the spectrometer.

3.3.15

optical pen

part of a chromatic probe (3.3.2) containing the chromatic lens and located close to the surface during the measurement

3.3.16

stray light signal

signal composed of the stray light entering the discrimination pinhole (3.3.11) , sensed by the detector when no sample is present, and the internal signal produced by the detector itself

Note 1 to entry: The stray light signal is generally captured during a calibration procedure in order to correct the measurements.

3.4.1

metrological characteristic

MC

characteristic of measuring equipment, which may influence the result of measurement

[SOURCE:ISO 14978:2006, definition 3.12]

Note 1 to entry: Calibration of metrological characteristics may be necessary.

Note 2 to entry: The metrological characteristics have an immediate contribution to measurement uncertainty.

3.4.2

measuring volume

range of the instrument stated as simultaneous limits on all spatial coordinates measured by the instrument

3.4.3

hysteresis

property of measuring equipment, or a characteristic whereby the indication of the equipment or value of the characteristic depends on the orientation of the preceding stimuli

Note 1 to entry: Hysteresis can also depend, for example, on the distance travelled after the orientation of stimuli has changed.

[SOURCE:ISO 14978:2006, definition 3.24]

Note 2 to entry: For lateral scanning systems, the hysteresis is mainly a repositioning error.

3.4.4

response curve

F_x , F_y , F_z

graphical representation of the function that describes the relation between the actual quantity and the measured quantity

Note 1 to entry: An actual quantity in X (respectively Y or Z) corresponds to a measured quantity x_m (respectively y_morz_m).

Note 2 to entry: The response curve can be used for adjustments and error corrections.

3.4.5

amplification coefficient

α_x , α_y , α _z

slopeof the linear regression curve obtained from the response curve

Note 1 to entry: There will be amplification coefficients applicable to the X, Y and Z quantities.

Note 2 to entry: The ideal response is a straight line with a slope equal to 1 which means that the values of the measurand are equal to the values of the input quantities.

Figure 3—Example of a non-linear response curve

Key

1	response curve	3	measured quantities
2	assessment of the response curve by polynomial approximation	4	input quantities

Figure 4—Example of the linearization of a response curve

Key

1	measured quantities	4	linearized response curve
2	input quantities	5	straight line whose slope is the amplification coefficient α
3	ideal response curve	6	local residual correction error before adjustment

3.4.6

instrument noise

internal noise added to the output signal caused by the instrument if ideally placed in a noise-free environment

Note 1 to entry: Internal noise can be caused by the electronic noise such as amplifiers.

Note 2 to entry: This noise typically has high frequencies which limit the ability of the instrument to detect small scale surface texture.

Note 3 to entry: The S-filter specified in ISO 25178-3 can reduce this noise.

3.4.7

static noise

N_s

combination of the instrument and environmental noise on the output signal when the instrument is not scanning laterally

Note 1 to entry: Environmental noise is caused by, e.g., seismic, sonic and external electro-magnetic disturbances.

Note 2 to entry: Notes 2 and 3 of 3.4.6 also apply to this definition.

3.4.8

dynamic noise

N_d

noise occurring during the motion of the drive units on the output signal

Note 1 to entry: Notes 2 and 3 of 3.4.6 also apply to this definition.

Note 2 to entry: Dynamic noise includes the static noise (3.4.7) .

3.4.9

sampling interval in X

D_x

distance between two adjacent measured points along the X-axis

3.4.10

sampling interval in Y

D_y

distance between two adjacent measured points along the Y-axis

3.4.11

digitization step in Z

D_z

smallest height variation along the Z-axis between two ordinates of the extracted surface

Note 1 to entry: The height of a point is evaluated by searching for the position of the maximum peak on the spectrometer curve. Although the lateral resolution of the spectrometer is relatively small (small number of pixels), the digitization step in Z of the chromatic probe (3.3.2) is improved with the use of sub-pixel algorithms.

3.4.12

lateral resolution

R_l

smallest distance between two features which can be detected separately

3.4.13

width limit for full height transmission

W_l

width of the narrowest rectangular groove whose measured height remains unchanged by the measurement