GB 6672-2001 Mechanical measurement method for the thickness determination of plastic films and flakes

GB 6672-2001 Mechanical measurement method for thickness determination of plastic film and sheet: The thickness measuring instrument should be able to achieve the following accuracy; - 100 um internal package live 100 pm) accuracy of 1 pm (see Note 1); - 100 um to 259 m (including 250 um) accuracy of 2 um; -—250 um with a precision of 3 pm
.

When the above measuring instrument requires a wider precision is not competent, this method should not be used, but a more suitable measuring instrument or measurement method
should be selected.

ISO4591:1992 "Plastic + - Film and sheet - Measurement of average thickness of samples, measurement of average thickness and yield of coils - Gravimetric method (gravimetric thickness)" stipulates the application of gravimetric analysis techniques to determine thickness
.

The measuring instrument should have a lower measuring surface with a flat surface and an upper measuring surface with a flat or convex surface, and all measuring surfaces
should be polished.

1.
When the upper and lower measurement surfaces are planar planes, the diameter of each measuring surface should be between 2.
5 mm and 10 mm, and the disparity between the two planes is less than 5 pm
.

The lower measuring surface should be adjustable) to meet the above requirements
.

The load applied to the specimen should be between 0.
5N and 1.
0N for
measurement.

2.
When the upper and lower measuring surfaces are convex planes, the radius of curvature of the upper measuring surface should be between 15 mm and zo mm, the diameter of the lower measuring surface should not be less than 5 mm, and the load that can be added to the measurement face of the specimen should be between
0.
1N and 0.
5N.

Note 2: The transfer output of the measured values can be carried out by ultramechanical methods< using micrometer >, optical (using mirror instrumentation) or electrical (inductive method
) and so on.

Testing equipment: PTT-03A thickness tester 3 specimens are intercepted along the entire width of the transverse at approximately 1 m from the longitudinal end of the sample, and the specimen is 100 mm
wide.

Except for folding samples for submission or packaging, the specimen should be free of creases and should not have other defects
.

Step 1 of 4: The specimen is conditionally adjusted for at least 1 h under the condition of (23 Shi 2) C, and for the moisture-sensitive film, the state adjustment time and environment should be determined
according to the specifications of the material under test, or according to the negotiation between the supply and demand sides.

2.
Each measuring surface of the specimen and the measuring instrument (2.
1) is free of pollution, such as oil and dust
.

3.
The zero point of the measuring instrument should be checked before the measurement, and the zero point
of each group of specimens should be re-checked after measurement.

4.
The probe should be gently lowered during the measurement to avoid specimen deformation
.

5.
Determine the location point of the thickness measurement by aliquoting the length of the specimen, as follows: a) the specimen length ≤300 mm, measure 10 points; b) the specimen length is between 300 mm and 1 500 mm, measure 20 points; c) the specimen length ≥1 500 mm, at least 30 points
.

For samples without trimming, measurements
should be started at 50 mm from the edge.

5 The accuracy of this test method is unknown, because no inter-laboratory data
are available.

Once the interlaboratory data is available, a description
of the accuracy will be added in a future revision.

6 Test Report The test report shall include the following: a) this standard number; b) complete identification of specimen information; c) measuring surface type and load; d) specimen length; e) number of samples tested; f) mechanically measured specimen average thickness, which is the arithmetic average of all measured values, accurate to 1 pm (0.
001 mm), if required, each measured value should also be given in the report; g) if required, the report should give the total number of measurements and standard deviation
。