1、International Standard 5636/ 1 INTERNATIONAL ORGANIZATION FOR STANDARDIZATlONWvlEYHAPOHAR OPTAHH3AUMR l-l0 CTAHAPTH3ALi Lair fvaleur moyenne) - Partie I : M or b) the rate of flow shall be measurable to an accuracy of + 5 % of the measured value. 1) IS0 5636/2, Paper and board - Determination of air
2、 permeance (medium range) - Part 2 : Schopper m b) to ensure steady operation of the device controlling the flow of air immediately before and during the time the deter- minations are being made; c) to ensure absence of vibration which could affect air displacement; d) to ensure that the test piece
3、is clamped uniformly without distortion; e) to ensure that the measurements are made with the ap- paratus on a level surface; f) to test half of the test pieces from one side and half from the other side. 11 Expression of results 11 .I Calculation Convert the measured values (see the annex) to give
4、the air per- meance (PI of each test piece, in micrometres per Pascal second pm/(Pa=s)l by means of the formula V 1000 x AApf where V is the volume of air, expressed in millilitres, which passed through the test area; A is the test area, in square metres; Ap is the pressure difference, in kilopascal
5、s; t is the test duration, in seconds. 11.2 Arithmetic mean Calculate the arithmetic mean of the air permeance, in micro- metres per Pascal second, to three significant figures. If there is evidence of a significant difference between the results for each direction of air flow through the test piece
6、 calculate a separate arithmetic mean for each. 11.3 Standard deviation Calculate the standard deviation or coefficient of variation of the air permeance for all replicate test results to two significant figures. In the Gurley test, the pressure is specified in terms of the mass and dimensions of t
7、he cylinder and the quality and level of the oil. 2 Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IS0 5636/l-1984 (E) 12 Test report f) the number of test pieces tested
8、 The test report shall include the following information : a) b) a reference to the appropriate part of IS0 5636; the date and place of testing; g) the pressure difference used, in kilopascals; h) the used; c . . duration, in seconds, or the flow c) all the information necessary for the complete id
9、en- tification of the sample; j) the arithmetic mean or means (see 11.2); k) the standard deviation or coefficient of variation (see d) the type of instrument used; 11.3); e) the temperature and relative humidity during the test; m) any deviation from the procedure specified. Copyright International
10、 Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IS0 5636/l-1984 (El Annex Conversion factors for different types of apparatus A.0 Introduction To obtain the air permeance of a test piece from r
11、eadings obtained using a particular type of apparatus, the appropriate formulae given below should be used. There are inherent differences between different types of ap- paratus, for example measuring head geometry, pressure dif- ference etc. For this reason, the factors used in the formulae should
12、not be used to convert readings made on one type of apparatus to equivalent readings on another. It is for this reason also that the type of apparatus used must always be reported. A.1 Conversion factors (see also clause 11 for symbols) A.1 .l Schopper apparatus a) Ap = 1,OOkPa V p =- t b) Ap = 250
13、kPa 0,4 v p =- t A.l.2 Bendtsen apparatus Ap = 1,47 kPa P = 0,011 3 4 where q is the rate of flow of air, expressed in millilitres per minute, passing through the test area. A.l.3 Potts apparatus Ap = 0,98 kPa P = 0,017 0 q where q is the rate of flow of air, expressed in millilitres per minute, pas
14、sing through the test area. A.l.4 Sheffield apparatus Ap = 10,3 kPa P = 1,62x- A where q is the rate of flow of air, expressed in millilitres per minute, passing through the test area A, in squaremillimetres. If the test area is 285 mm2 P= 0,005 68 q A.l.5 Gurley apparatus 127 p=- t A.2 Equivalent v
15、alues The equivalent values on different apparatus of an air per- meance of 1 pm/(Pas) are given in the table. I Apparatus 1 Values Schopper 1 ml/s at 1 kPa Schopper 2,5 ml/s at 2,5 kPa Bendtsen 88 ml/min at 1,47 kPa Potts 59 ml/min at 0,98 kPa Sheffield 176 ml/min at 10,3 kPa and 285 mm2 Gurley 127
16、 s at 1,23 kPa” * Inverse relationship. Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-This page intentionally left blank Copyright International Organization for Standa
17、rdization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-This page intentionally left blank Copyright International Organization for Standardization Provided by IHS under license with ISONot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
