ISO 18903:2002 イメージング材料—フィルムと紙—寸法変化の決定 | ページ 6

3.1

conditioning

exposure of a specimen to air at a given relative humidity and temperature until equilibrium is reached

3.2

differential dimensional change

difference between the dimensional changes of the material in the two principal directions (length and width)

Note 1 to entry: Polyester-based films frequently have maximum and minimum dimensional changes in directions other than the length or width. These can be determined by rotating and viewing the uncoated base between a pair of crossed polarizers. When the direction corresponding to either the maximum or minimum dimensional change is coincident with the optical axis of one polarizer, there is minimum light transmission through the base.

3.3

dimensional change due to processing

permanent dimensional change caused by photographic processing

Note 1 to entry: This may be the conventional wet chemical processing, vapour processing or heat processing. It is measured after conditioning at the same relative humidity and temperature as used for the original measurement and is expressed as a percentage.

3.4

dimensional change due to processing plus ageing

permanent dimensional change that occurs as a result of processing plus ageing of the processed material

Note 1 to entry: It is measured after conditioning of the processed, aged film or paper at the same relative humidity and temperature as used for the original measurement and is expressed as a percentage.

3.5

dimensional hysteresis

difference in the absolute dimensions of a specimen in equilibrium with air at a given relative humidity, when conditioned from a higher relative humidity and when conditioned from a lower relative humidity

3.6

humidity coefficient of expansion

change in dimension per unit length per 1 % change in relative humidity at constant temperature

3.7

humidity expansion [contraction]

dimensional change caused by the gain (or loss) of moisture following changes in the relative humidity of the ambient air at constant temperature

3.8

length direction

direction of the film or paper parallel to its forward movement in the film- or paper-making machine

Note 1 to entry: This is also termed “grain” or “machine direction” in the case of papers.

3.9

preconditioning

establishment of a moisture content history by conditioning the specimen at a relative humidity above or below the conditioning relative humidity used for measurement

Note 1 to entry: The purpose of preconditioning is to control the effects of hysteresis (see 3.5).

3.10

thermal coefficient of expansion

change in dimension per unit length per 1 °C change in temperature at constant relative humidity

3.11

thermal expansion [contraction]

dimensional change caused by a rise (or fall) of temperature at constant relative humidity

Note 1 to entry: This is an apparent thermal expansion, since the moisture content of film varies slightly with temperature at constant relative humidity. However, the primary effect is thermal expansion. Thermal expansion is less important for paper because of the small changes involved, particularly compared to humidity effects.

3.12

width direction

direction of the film or paper at right angles to the length direction

Note 1 to entry: This is also termed “cross direction”.