GB/T 7962.15-2010Test methods of colourless optical glass - Part 15: Resistance to humidity (English PDF)

1 Scope

This part of GB/T 7962 specifies the test conditions, procedures and classification methods for the resistance to humidity of colourless optical glass.

This part is applicable to testing the resistance to humidity of colourless optical glass.

2 Normative references

The following documents contain provisions which, through reference in this part of GB/T 7962, constitute provisions of this part. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.

GB/T 678 Chemical reagent - Ethanol

GB/T 6682 Water for analytical laboratory use - Specification and test methods

GB/T 12591 Chemical reagent - Diethyl ether

3 Terms and definitions

For the purposes of this part, the following terms and definitions apply.

4 Theory

After the optical glass is eroded by the atmosphere, its surface produces metamorphic layers such as "white spot" or "blushing". The metamorphic layer obviously enhances the scattering power of parallel light. Therefore, the degree of metamorphism of the eroded surface may be evaluated according to the scattering intensity of light on the eroded sample surface. Put the glass sample polished on both sides in saturated steam (with a temperature of 70°C±1°C) for 7 days and nights, then measure its scattering to light with the device shown in Figure 1.