SJ/T 10938-1996 Test method for light transmittance (τ546) of screen glass for color picture tubes SJ/T10938-1996 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Method of measurement for light transmissivity(t546)of color pictrure tube glass panelGB9474.3—88
Reduced to SJ/T10938-96
This standard specifies the test method for glass light transmittance (t546), applicable to color picture tube screen glass. 1 Principle of the method
When light is incident vertically on a transparent object, the ratio of the luminous flux of the transmitted light to the incident light is the light transmittance of the object, and the measurement is carried out on a spectrophotometer. For color picture tube screen glass, the incident light with a wavelength of 546nm is specified, and the sample thickness is specified to be 10.16nm. 2 Instruments and Equipment
2.1 Grinder
2.2 Polisher
2.3 Micrometer
2.4 Spectrophotometer
3 Sample Preparation
Cut a sample of 30mm×40mm from the center of the screen. The sample should not have defects such as stones, bubbles and stripes, and be annealed. Grind and polish. The two surfaces of the sample are required to be parallel, and the thickness difference at each location should not exceed 0.02mm. The surface should be flat, smooth, transparent, and clean. It is used to measure the thickness with a micrometer. 4 Test Steps
Place the sample vertically in the optical path of the spectrophotometer, and measure the light transmittance of the sample to air at a wavelength of 546nm. 5 Calculation Results
Calculate the light transmittance at the specified thickness (10.16mm) according to the following formula. t, =+8c(1-r)* × 100%-
Wherein: %—light transmittance of the sample with specified thickness (10.16mm), %—light transmittance of the measured actual thickness, %;.-actual measured thickness, mm,
(n1)2
r—surface reflection coefficient【r
n-refractive index of the sample.
6Test Reportwww.bzxz.net
(n+1)2
Approved by the Ministry of Electronics Industry of the People's Republic of China on April 29, 1988TTKNTKAa
Implementation on December 1, 1988
The test report should include the following contents:
Light transmittance T846 (%);
Specified thickness of the sample is 10.16mm,
Actual thickness of the sample:
Instrument model.
Additional Notes:
GB9474.3-88
This standard was drafted by Factory 4400 of the Ministry of Electronics Industry and the Standards Research Institute.
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