JJG 920-1996 Verification Procedure for Diffuse Transmission Visual Densitometer JJG920-1996 Standard download decompression password: www.bzxz.net
This procedure is applicable to the verification of newly manufactured, in-use and repaired diffuse transmission visual densitometers.

The People's Republic of China National Metrology Verification Regulations. IJG 920—1996
Diffuse Transmission Visual Densitometer
Published on November 12, 1996
Implemented on May 1, 1997
Published by the State Bureau of Technical Supervision
J.1G 92—1996
Verification Regulations for Diffuse Transmission Visual Densitometer DensitometerJJG92D—1996
This standard was approved by the State Technical Supervision Bureau on November 12, 1996, and was implemented on May 1, 1997.
Responsible unit: Shandong National Institute of Planning Science Drafting unit: Hebei Metrology and Testing Research Institute, China Institute of Metrology
The drafting unit is responsible for the technical signature of this standard. The main drafter of this standard:
Te Changgui
Fan Mingming
Xin Jia Drafting person:
JIG 920
[China Institute of Metrology]
[Hebei Institute of Metrology and Testing)
(China Institute of Metrology)
[China Institute of Metrology]
(Hebei Institute of Metrology and Testing)
[Hebei Institute of Metrology and Testing)
Technical requirements
Verification conditions
Verification items and verification methods
Verification result processing and verification cycle
JJG920—1996
Appendix! Appendix 2 Geometric conditions for standard wet transmission density Appendix 3 Spectral conditions for standard visual density measurement Appendix 4 Format of verification record Appendix 4 Format of the back of verification certificate and verification result notice JJG1920:1996 Verification procedure for diffuse transmission visual densitometer This procedure is used for the verification of diffuse transmission visual densitometers newly manufactured, in use and after repair. Overview Diffuse transmission visual densitometer (hereinafter referred to as densitometer) is a metering instrument used for optical density measurement in industries such as film processing, photographic film, printing plate, industrial exploration, medical care, labor protection, etc. The optical transmission density is defined as the common logarithm of the transmittance ratio, that is: N-1/2/2 where N is the ratio of the light path through the sample to the aperture flux: 1-04 Substituting formula 2) into (1) we get = g@e
武中: , optical transmittance density, unit is 1. (1)
The density meter is a device designed according to the above definition and the geometric and spectral conditions (Gamma 1 and Gamma 2) specified in the international standards GL11500 and GL1155. It usually consists of a light source system, a filter group, a light detector and an indicator.
II Technical requirements
1 Appearance requirements
1.1 The density meter should have the following markings: device name, shape, terminal number, manufacturer, time of manufacture. 1.2 The density meter can be placed stably on the workbench. All regulators, buttons and switches should be correctly placed and can work properly. All fasteners and cable connectors should fit tightly and have good contact. 1.3 The display of the density meter should be clear and there should be no broken lines on the display. The scale lines and scale characters of the needle display should be complete and evenly marked. The width of the indicator line should not be greater than the scale line width, and should be 1.4 Densitometer shall be equipped with special working density plate, which is divided into two types: color plate base and disk base. 2 Zero point deviation
When calibrated according to the method specified in Article 10, the zero drift of the density meter shall not exceed +1.3 Image quality
When calibrated according to the method specified in Article 11, the density stability of the density meter shall not exceed +0.014 Stability
When calibrated according to the method specified in Article 12, the density stability shall not exceed +.1.5 Indication error
—199
When calibrated according to the method specified in Article 13, the density meter cloud value error shall not exceed +0.021
(2.0-1824.0)
3. Calibration conditions
6. Standard environment
The temperature is 101-3℃, The relative density is 20 bar, and the calibration is carried out under the condition of no strong light exposure.
? Cage equipment
7.1 Standard visual (black and white) density film: The density value range should be 4.0, density level - less than 1 level: the density should be measured by the working standard week calibration, and its value should comply with the provisions of 21989.
7., 2 Wash the ball, camel hair .
3 ICBC to the line in the set,
4 inspection items and inspection methods
8 inspection items H
The shrinkage meter must be checked monthly according to 5 cases
5 external inspection
Thanks for sending the meter carefully, the electricity is in the working state and the visual method is used to judge. The first article of the voice station stipulates: 10bzxz.net
The counting and transfer inspection treasure
The meter startup item is in normal working condition. After the state, adjust the displayed value to zero, and measure the density value of the standard density sheet with a density of about 2.0. The drift of its zero position should meet the requirements of the following articles: 11 Repeatability verification
After the density card is calibrated with a standard density sheet with a density of about 2.0, the density value of this point is measured continuously for 5.5 times. The average value of the indicated value and the maximum deviation of each indicated value should meet the requirements of Article 3. 12 Stable density
After the density card is calibrated with a standard density sheet with a density of about 2.0, the density value is measured once every 5 minutes, for a total of 5 times, and the maximum deviation should meet the requirements of Article 4. 13 Indication drift
First, use a standard density sheet with a density of 2.0 to measure the density value of each standard density sheet, and then measure the density value of each standard density sheet. The test is performed 3 times. The deviation of the average value of each measured value from the standard value meets the requirements of Article 5. 5. Verification result processing: Verification cycle
14. Repeatability and indication error are the ten major verification items. The other non-ten major verification items are tested within one year. If one of them exceeds the tolerance or fails to meet the standard, it will be determined as a failed instrument. 15. Densitometers that pass the verification will be issued with a verification certificate. Densitometers that fail the verification will be issued with a verification notice.
16. The verification cycle is one year. The certificate of the last verification should be brought along each time the instrument is sent for inspection. 3. Appendix 1
.1. IG920-1996
Geometric conditions for standard diffuse transmission density measurement (see GB11500-1989) | |tt||The geometric model for measuring standard visual transmission density can use a directional illumination and a directional detector to measure the transmission of the sample. This optical path arrangement is called the "transmission model" (Figure 1: If the optical path arrangement of directional illumination and diffuse detection is used, it is called the "diffuse emission model" (Figure 2). These geometric formulas can be described by a specified diffuse distribution, which is equivalent to the angular distribution of the luminance; or the angular distribution of the brightness. The density measured according to the above geometric model is called the standard transmission density or simply the diffuse density: 5* x, .90
Figure 1 Visual transmission mask model
2 Source radiation flux modification
Appendix 2
J1920-1996
Spectral conditions for standard visual density measurement
(Refer to GB 11501—1989)
The spectral type of the standard visual density measurement is determined by the logarithmic value of the ratio spectrum product with a wavelength of 1(Fm as an interval, that is, the relative spectral power distribution 5H of the illumination source with a wavelength of 101n as an interval is multiplied by the cabinet spectral response V corrected by the detector plus the V () filter, and the optical harmonic product is obtained. The logarithmic value of the spectral product H. See Table 1. Table 1 Logarithmic value of the optical product of standard visual density measurement (rounded to 5.0000)
(standard)
Wavelength m
(standard)
Appendix 3
Only by name
Manufacturer
Send to the unit|| tt||Fixed loop parts
Verifier
2.Zero point source shift
Zero point value before creation
3.Repeat stack
Measurement result
Indication (D)
JJG920-:1996
Record format
Instrument number
Control month
Certificate number
Verifier
Zero point value after creation
Seasonal drift
Half mean
Big error
4.Accuracy
Standard value
5.Indication error
Standard error
,IJC 920—1996
Interval 5 rin measurement low
Early detection (D)
Maximum human error
Appendix 4
J1G 920—1996
Verification certificate and verification result notice back format standard value ()
Verification environment conditions:
This point is full of
Conclusion:
Measurement accuracy ()
Indicated error ()
Relative accuracy
Specification
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