ASTM C1377-97(2003)

1.1 This test method covers calibration or verification of calibration or both, of surface-stress measuring devices used to measure stress in annealed and heat-strengthened or tempered glass, using polariscopic or refractometry based principles.

1.2 This test method is nondestructive.

1.3 This test method uses transmitted light, and therefore, is applicable to light-transmitting glasses.

1.4 This test method is not applicable to chemically tempered glass.

1.5 Using the procedure described, surface stresses can be measured only on the "tin" side of float glass.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.