GB/T 7962.23-2019Test method of colourless optical glass - Part 23: Resistance to climatic (English PDF)

1 Scope

This part of GB/T 7962 specifies the principle, environmental conditions, test steps, data processing and classification for the resistance to climatic of colourless optical glass.

This part is applicable to colourless optical glass, and may serve as a reference for other types of glass.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 678 Chemical reagent - Ethanol

GB/T 903 Colourless optical glass

GB/T 1185-2006 Surface imperfections of optical elements

GB/T 6682-2008 Water for analytical laboratory use - Specification and test methods

GB/T 12591 Chemical reagent - Diethyl ether

3 Principle

Erosion caused by atmosphere brings about metamorphic layers such as "white spot" or "blushing" on the surface of the colourless optical glass. The degree of erosion on the glass surface is determined by measuring the turbidity difference of the testing sample before and after erosion using a turbidimeter with integrating sphere. See Figure 1 for the schematic diagram for optical glass turbidity measuring device.

Keys:

1 - - light source;

2 - - collimator;

3 - - testing sample;

4 - - integrating sphere;

5 - - photoelectric detector;

6 - - light trap;

7 - - standard white plate.

Figure 1 Schematic diagram for optical glass turbidity measuring device

4 Environmental conditions

Unless otherwise specified, tests shall be carried out under the following environmental conditions:

a) temperature: 15~35°C;

b) relative humidity: 20%~80%;

c) atmospheric pressure: atmospheric pressure on the test site.

5 Reagents