Micrographics; Reflectance test target used in the test target for inspecting the quality of micrography of technical drawing

The reflectivity gray card specified in this standard is a component of the "test plate for microfilm quality inspection of technical drawings" and is used to detect the diffuse transmission visual density of silver halide microfilm. The reflectivity gray card is limited to the use of reflected light for photography. GB/T 8990-1988 Microfilm Technology Reflectivity gray card for microfilm quality inspection of technical drawings GB/T8990-1988 standard download decompression password: www.bzxz.net
The reflectivity gray card specified in this standard is a component of the "test plate for microfilm quality inspection of technical drawings" and is used to detect the diffuse transmission visual density of silver halide microfilm. The reflectivity gray card is limited to the use of reflected light for photography.

National Standard of the People's Republic of China
Micrographics-Reflectance test targetused in the test target for inspectingthe quality of mlcrography
of technical drawng
1 Subject content and scope of application
UDC T78.14
GB B990—88
The reflectance gray card specified in this standard is a component of the "micrographic quality test target for inspecting technical drawings". It is used to detect the transmission visual density of silver halide microfilm. The reflective gray card is limited to the use of reflected light for shooting. 2 Composition of reflectance gray card
2.1 It is made of two pieces of material with neutral carbon on the surface and 120mm×120mm. Reflectivity of reflectivity gray plate A or reflective density Reflectivity of reflectivity gray plate B R457 = 50 ± 3% J457 = 0.276 ~ 0.328 R457 = 6 ± 0.4% D457 = 1. 194 ~ 1. 252 Note: When measuring reflectivity, the filter used is required to transmit the center of the light, the wavelength is 457m, and the light source is the light source. 2.2 The surface of the reflectivity gray plate has no obvious gloss. 3 Application of reflectivity gray plate 3.1 Reflectivity gray plates A and B, No. 1 or No. 2 test chart, reduction test tape, and reduction digital card constitute the test standard for inspecting the microfilm quality of technical drawings.
8.2 The reflectivity gray card is used to control the density of the microfilm image. After the film is exposed and washed, when the negative image density of the reflectivity gray card A is between 1.0 and 1.2, and the negative image density of the reflectivity gray card 3 is less than 0.1, the test standard can be used to test the comprehensive resolution or clarity of the microfilm.
Additional remarks:
This standard was proposed by the National Microfilm Technology Standardization Technical Committee. This standard was drafted by the School of Archives of Renmin University of China. The main drafters of this standard were Liu Pei and Zheng Qing.
Approved by the National Bureau of Standards on April 11, 1988bzxZ.net
Implemented on December 1, 1988
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