This standard applies to the test of thermochromic properties of transparent quartz glass tubes and other products. GB 4121-1983 Test method for thermochromic properties of quartz glass GB4121-1983 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Test method for stability tothermal darkening of silica glass
The test method for stability tothermal darkening of silica glass This standard is applicable to the inspection of the thermal darkening performance of transparent quartz glass tubes and other products. Test principle
UDG 669.192: 666
.11.01
GB 4121—83
After heat treatment, the light transmittance of transparent quartz glass changes. The change in transmittance at a wavelength of 290nm is used as the degree of color change performance. 2 Preparation of test samples
2.1 Quantity: three.
2.2 The shape and size shall comply with the provisions of the following table: mm
Pipe or product
Pipe with a diameter less than 40
Pipe with a diameter greater than 40
Test specimen shape and size
Tube length 30~40, cut into two parts axially
Tube length 30~40, cut into test specimens with a chord width of 20 30×15×s (plate thickness) test specimens
2.3 The appearance quality of the test specimen shall comply with the corresponding JC177-81 "DTSi transparent quartz glass tube" or JC224--81 "DTS2 transparent quartz glass tube" provisions.
3 Test equipment and materials
3.1 High-temperature electric furnace, working temperature 1000±20℃. 3.2 One electric oven.
3.3 One UV spectrophotometer, with a transmittance measurement accuracy of ±1%. 3.4 A gas-refined quartz glass sample box with a lid, with a specification size of 100mm×80mm. 3.5 One chrome-plated crucible tongs and one bamboo clip.
3.6 One 125mm vernier caliper, with an accuracy of 0.02mm. 3.7 Chemically pure anhydrous ethanol.
3.8 Absorbent gauze or absorbent cotton.
3.9 Glass beaker.
4 Test preparation
4.1 Sample preparation:
National Bureau of Standards 1983-12-30 Issued
1984-11-01 Implementation
GB4121-83
4.1.1 Place the sample in a beaker with anhydrous ethanol and soak for 15-20 minutes, take it out, and wipe it with absorbent gauze. 4.1.2 Clean the sample box and lid for the test in the same way. 4.1.3 Place the sample in the sample box with a clamp, place the sample box and lid with the sample in an oven, dry (do not cover the lid during drying) and set aside.
4.2 Heating
Raise the furnace temperature to 1000±20℃.
4.3 Adjust the UV spectrophotometer.
5 Test steps
5.1 Adjust the wavelength dial of the spectrophotometer to 290nm and calibrate 100% transmittance. 5.2 Place the treated sample in the sample holder of the UV spectrophotometer and record the transmittance curve from 200 to 400nm. 5.3 Place the sample with measured transmittance in the sample box, cover it with a lid, and place it in the high-temperature electric furnace prepared in 4.2 and keep it warm for 2 hours. 5.4 Take out the sample box with the sample from the furnace, cool it in the air, and measure the transmittance of the sample in 5.2. 6 Result calculation
6.1 The color change performance of quartz glass after heat treatment is expressed as the transmittance change value △T, %/mm, of the sample with unit thickness at a wavelength of 290nm, and is calculated as follows:
T, -T2
Where: T, transmittance of the sample at 290nm before heat treatment, %T2——transmittance of the sample at 290nm after heat treatment, %, d
-sample thickness, mm.
6.2 Take the average value of the transmittance change values ​​of the three samples as the transmittance change value of this batch of samples. 7 Test record and test report
7.1 Record the sample number and the unit of delivery on the recording paper of the spectral transmittance curve. 7.2 Test report: Fill in the test report in the following format and content. Quartz glass transmittance measurement test record
Sample submission unit
Sample name
Test date
Sample number
Sample thickness
Sample submission date
Sample number
Tester,
Test results
Sample submission unit
Sample nameWww.bzxZ.net
Test date
Sample number
Additional notes:
GB4121—83
Quartz glass heat treatment discoloration performance test reportSample submission date
Sample number
Transmittance change value AT at a wavelength of 290nm, %/mmTester
Testing unit:
Responsible person
This standard is proposed by the State Bureau of Building Materials Industry and is under the jurisdiction and interpretation of the Building Materials Science Research Institute. This standard was drafted by the Building Materials Science Research Institute. The main drafters of this standard are Liu Jun'e and Zhu Mingdi.
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