This standard specifies the method for determining the visual density of diazo film diffuse transmission and the visual density of microbubble film projection, and also determines the density value of second-generation microforms. This standard applies to second-generation diazo and microbubble copies produced from first-generation silver salt microforms made from originals and COM. It is not applicable to the print density of second-generation diazo and microbubble copies. GB/T 13984-1992 Micrographic Technology Diazo and Microbubble Film Visual Density Technical Specification GB/T13984-1992 Standard Download Decompression Password: www.bzxz.net
This standard specifies the method for determining the visual density of diazo film diffuse transmission and the visual density of microbubble film projection, and also determines the density value of second-generation microforms. This standard applies to second-generation diazo and microbubble copies produced from first-generation silver salt microforms made from originals and COM. It is not applicable to the print density of second-generation diazo and microbubble copies.

National Standard of the People's Republic of China
Micrographics
Technical Specifications for Diazo and Vesicular Films Visual Density Micrographics-Visual density specifications for diazu and vesicular films GB/T18984---92
This standard is equivalent to [S(8126-19%(Micrographics-Diazo and Vesicular Films-Visual Density-Technical Specifications》1 Subject content and scope of application
This standard specifies the method for determining the diffuse transmission visual density of diazo film and the projection visual density of microvesicular film, and also determines the density value of the second-generation microforms.
This standard is applicable to the second-generation diazo and microvesicular copies produced by the first-generation silver salt microforms made from mountain originals and ()M. It is not applicable to the print density of the second-generation diazo and microvesicular copies. 2 Reference standards
B 6159.1 Vocabulary of Microfilm Technology Part 1 General Terms GH6159.2 Vocabulary of Microfilm Technology: Part 4 Materials and Packaging 3 Terms
3.1 Visual Density
The density measured when the spectral response of the densitometer receptor is the same as the photopic function of the human eye, that is, the density measured in the following two cases: a. The spectral product of the measurement system is (:IF: the product of the relative spectral power distribution of the light source A and its relative spectral luminous efficiency within the photopic function (). Www.bzxZ.net
b. The light source of the densitometer is the S light source for transmission density measurement (that is, the CIEA light source corrected in the correction and infrared spectral regions to prevent overheating of the sample and optical components, 3.2 Minimum visual density value of heavy film 1mi:
The diffuse transmission visual density value formed by diazo film after sufficient exposure and development, more than .3 Maximum projection visual density value of microbubble film (max) The projection transmission visual density value of the microbubble area formed after the microbubble film is fully exposed and developed. 3.4 CIF A light source
Based on Planck's second radiation constant (-1.4388×10^m*K), the radiation flux emitted by a gas-filled spiral tungsten filament lamp when the color temperature is 2856K
3.5 Printing density
A physical quantity used to describe the modulation effect of the master film in the printing system (reflection, refraction, transmission, absorption, scattering or change of the polarization state of light, etc.). Its value is a function of the spectral energy distribution of the light source, the spectral characteristics of the optical system, and the harmonic sensitivity of the printing material.
Determination of diffuse transmission density of heavy ammonia film 4.1 Determination method
Approved by the State Administration of Technical Supervision on 19921217 and implemented on June 1, 1993
GB/T 18984.92
The visual density of diazo copies shall be determined by using a standard transmission meter (see Appendix A1). The true diameter of the aperture for the true determination shall be within the range of 5 mm to 3 mm (inclusive). For this purpose, an area corresponding to the aperture diameter shall be selected on the microform slide for determination.
.2 Visual Density of Diazo Copies
4.2.1 Copies of Original Microforms
The minimum visual density of the image on a diazo copy shall be greater than the minimum visual density of the diazo film (1)1, but less than 0.15. For second generation positive copies (2P), the density shall be determined in the background area of ​​the image; for second generation negative copies (2N), the density shall be determined in the image area of ​​the density test plate with an inversion factor of 636 or in the transparent area between the frames. Generally, the most satisfactory copy is obtained when the area with a visual density value of 0.35 on the silver master is copied to the diazo film and the resulting visual density is also 0.35.
Table 2.2 Copies of CM microforms
The minimum visual density value of the diazo copy image should be greater than the minimum visual density value of the diazo film (1m). And less than 15. The background visual value of the image of the first generation negative copy (2N) should not be less than 1., and positive copy films are generally not used:
5 Determination of the projected visual density of microbubble film
5.1 Determination method
When determining the projected visual density of microbubble copies, a projection visual densitometer with a relative aperture of 5 should be used (see Appendix 3) 5.2 Projected visual density value of microbubble copy films 5.2.1 Copies of original microforms
The projected visual density value of the image background of the second generation positive copy (2) should not be greater than 0.25. The projected visual density value of the image background of the second generation negative print (2N) shall be equal to or greater than 1.20 and less than the maximum projected visual density value (x) of the microfilm. 5.2.2 COM Microfilm Copy
The projected visual density value of the background of the second generation negative print (2N) shall be equal to or greater than 1.80 and less than the maximum projected visual density value (max) of the microfilm.
Generally, the density value is about 85% of the maximum projected visual density value (max) of the microfilm, and the quality of the copy is most satisfactory. A1ISQ Standard Diffuse Visual Density
GB/T 13984.- 92
Appendix A
[ISO standard density
(reference)
The geometric conditions for measuring ISO standard diffuse transmission visual density (LI) are divided into two forms: "scattered distribution" and "directional distribution", and the measurement results of the two forms are the same. Diffuse distribution is measured using a radiation source and a fixed-time collection channel, that is: the half angle () of the incident light on the film (center:) and the collection half angle (,) of the collector collecting the film transmitted light (4) should meet 8590, 10 respectively; directional distribution is measured using a directional irradiation light source and a diffuse collector, that is: k,%10,85\,r than 90 (see Figure A1). The light with a half angle between 85\ and 90 is obtained using an opalescent reflector. The spectral conditions of the measurement require the use of an SH ratio source as the light source of the densitometer, and the spectral response () of the collector should be the same as the spectral sensitivity of the human eye. ISO standard diffuse transmission visual density can be recorded as: Lr (90" white diffuser, SH:10:V). ki'h,r
8，avoid time distribution
b. Directional distribution formula
A21S（) Standard f/4.5 projection transmission visual density IS（) Standard [/4,5 projection transmission visual density (L) The geometric conditions for measuring are that the half angle () of the film incident light and the collection half angle (,) of the measuring collector are both 6.4±0.2 (see Figure A2), which is equivalent to an ideal projection system with a relative aperture of the lens: 4.5. The spectral conditions for measurement require that S light source be used as the light source of the densitometer, and the spectral response (s) of the measuring collector should be the same as the sensitivity of the human body. 1SO standard projection transmission resolution can be recorded as, (6.4, S6.4:) Additional remarks:
Human light table
GB/T 13984-- 92
This standard is proposed by the National Technical Committee for Standardization of Microfilm Technology. This standard is drafted by the Quality Branch of the National Microfilm Technical Committee. The main drafters of this standard are Rong Defan and Li Sanbao.
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