1、November 2006DEUTSCHE NORM Translation by DIN-Sprachendienst.In case of doubt, the German-language original should be consulted as the authoritative text.English price group 7No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beu
2、th Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 83.140.10!$I 5 to 10 0,5 m 10 to 100 1 m 100 2 % NOTE For films having a thickness greater than 200 m, it may sometimes be adequate to use gauges with an accuracy of 10 m. 4.2 Thickness gauge
3、for method F 4.2.1 Any mechanically scanning thickness gauge with a flat-tipped feeler, for example a precision dial indicator as in DIN 879-1 or an electrical thickness gauge, may be used that has a dial with scale intervals of 1 m (= 0,001 mm) or a digital display registering units of 1 m. 4.2.2 T
4、he measuring surfaces shall be 8 mm to 16 mm in diameter and the contact pressure shall be 50 kPa to 100 kPa or 10 kPa to 100 kPa. One of the surfaces shall be circular, while the other may be identical and precisely aligned with the first (an arrangement particularly recommended in the case of hard
5、 or stiff sheets) or be as large as desired. 5 Test specimens Cut strips of suitable width across the full width of the plastic web. If data relating to thickness variation in the extrusion direction is required, cut suitable strips of agreed length in the longitudinal direction of the specimen. The
6、 test specimens shall not be creased or defective in any other way. 6 Preparation of test specimens 6.1 Unless otherwise agreed, the test specimens shall be measured as delivered and without any conditioning. 6.2 In arbitration cases relating to the maintenance of manufacturing tolerances, the test
7、specimens shall be stored in a DIN EN ISO 291 23/50-2 standard atmosphere for 48 hours or more, until their mass does not vary by more than 0,5 % when measured at intervals of at least six hours. 6.3 If the thickness is to be used as input for another test, for example for a tensile test or for dete
8、rmining electrical properties, it shall be measured under the conditions specified for that test. 7 Procedure 7.1 Perform the thickness measurements in an atmosphere meeting the requirements of clause 6 or, in the case of as-delivered test specimens, in a DIN EN ISO 291 23/50-2 standard atmosphere.
9、5 DIN 53370:2006-11 7.2 Before measurement, check that there is no dust or other contamination on the test specimen or on the surfaces of the thickness gauge. Ensure that any convexity of the test specimen does not result in measurement errors. When measuring convex surfaces using method P, it is of
10、ten sufficient to insert the test specimen into the gauge with the concave surface facing the spherical measuring surface. Lower the upper measuring surface gently onto the test specimen, making sure that the measuring surface does not deform the test specimen. 7.3 Before and after measurement, chec
11、k that the gauge is correctly zeroed. 7.4 Measure the thickness at ten or more equally spaced points distributed over the entire length of the test specimen roughly along its centre line. In the case of untrimmed specimens, ignore 50 mm edge zones on either side. The distance between the individual
12、points shall not exceed 20 cm. If a specimen is too narrow for it to be practical to measure the thickness at ten points across the width of the web, the number and arrangement of the points may be varied by agreement. 7.5 If the thickness at some measurement points on a test specimen varies markedl
13、y from that at the other measurement points, check the test specimen and the measurement surfaces for dust again as in 7.2 and repeat the measurements at the same measurement points on the test specimen. Do not include any points at which repeat measurements cannot be obtained within the allowed tol
14、erance. 7.6 Report the thickness of the test specimen as the arithmetic mean of the individual measurements, in mm or in m. Report any other statistical values if the need arises. 8 Test report The test report shall include the following details: a) a reference to this standard; b) type and descript
15、ion of plastic films; c) conditioning of test specimens; d) method of measurement used; e) contact pressure and measurement area (in the case of method F); f) contact force (in the case of method P); g) number of measurement points; h) mean and standard deviation of the thickness of the plastic film
16、, in mm or m, to within the agreed tolerances; i) any deviations from this standard; j) date of testing. 6 DIN 53370:2006-11 Annex A (informative) Explanatory notes DIN 53370:1976-02 was limited to specifying a method of determining the thickness of smooth, non-embossed plastic films and deliberatel
17、y rejected method F described in DIN 53370:1959-07 because the possibility of measurement errors due to lack of parallelism of the measurement surfaces could not always be ruled out. This led to discussion of the general principles with the industries and testing institutes concerned and it became c
18、lear that measuring instruments are now available in which it is virtually impossible for the measurement faces to depart from parallelism. This consequently removed any obstacle to including both methods in this standard. In practice, method F is used to determine what was then called the “mean” th
19、ickness, as is usual, for example, in the case of plastic sack sheeting. The methods described here are used not only for plastic films and sheeting, but also for other materials, resulting in the preparation of a number of standards, large sections of which are identical and differ essentially only
20、 in specifying contact pressures and contact forces to suit the materials. Consequently, as a result of agreements with other bodies, DIN 53370 primarily specifies the methods of measurement. The specification of contact pressure and force remains the province of the specification standards. Table A
21、.1 provides an overview of the measurement geometries and contact pressures for various fields of application. Table A.1 Requirements for some fields of application Field of application Imitation leather (DIN EN ISO 2286-3) Roofing sheets (DIN 16726) Plastic sack sheeting (DIN 55543-1) Diameter of m
22、easurement surface mm 10 10 8 Contact pressure kPa 50 20 20 to 150 7 DIN 53370:2006-11 8 Bibliography DIN 16726, Plastic roofing felt and waterproofing sheet Testing DIN 55543-1, Packaging test Test methods for plastic sacks Part 1: Determination of film thickness DIN EN ISO 2286-3, Rubber- or plastic-coated fabrics Determination of roll characteristics Part 3: Method for determination of thickness ISO 4593:1993, Plastics Film and sheeting Determination of thickness by mechanical scanning
