This standard specifies four methods for the measurement of the dimensions of solid vulcanized or thermoplastic rubber test pieces or products for test purposes, three contact methods, designated A, B and C, and one non-contact method, designated D. The method to be used is selected according to the magnitude of the dimension to be measured and to the desired accuracy. Method A ? for dimensions less than 30 mm. Method B ? for dimensions of 30 mm up to and including 100 mm. Method C ? for dimensions over 100 mm. Method D ? non-contact procedure for all dimensions. Other measuring methods may be used when special condition arise, for example when the test piece or product has a curved surface or complex shape.