JJG 922-1996 Verification Procedure for Vertex Power Standard of Phoroptor JJG922-1996 Standard Download Decompression Password: www.bzxz.net

National Metrology Verification Regulations of the People's Republic of China JJG 922—1996
Vertex Power Standard Devices of Verlex Powerfor Refrnctometers
1996-11-18 Issued
1997-05-01 Implementation
National Technical Supervision Department Issued
JIG922
Verification Regulations
Yerificatinn Rcgulatiott of thc.Stauldard Devices of Vcrtex
Power for Retractometers
IIG922—1996
This inspection procedure was approved by the National Technical Supervision Bureau on November 18, 1996, and will be implemented on May 1, 1997.
Responsible unit: China Academy of Planning and Engineering Drafting unit:
Shanyin Institute of Metrology
The drafting unit is responsible for interpreting the technical text of this regulation. The main drafter of this regulation:
Ma Zhenya
Participating drafter:
Liu Wenli
.IJG 922—1996
(China Institute of Metrology)
(China Institute of Basic Sciences)
(National Institute of Planning and Technology)
Technical requirements
Verification conditions
Verification items and methods
Verification result processing and verification cycle
JJC:922:-1996
JG 922—1996
Verification Procedure for Ophthalmometer Quality Standards
This procedure is applicable to the verification of newly manufactured and repaired optometry quality standards: 1. Overview
In order to verify standard and custom optometry equipment, it is necessary to use optometry quality standards. The quality measurement values ​​of the optometry equipment shall be marked as 1: The quality standard is an objective standard of one or more types.
The design of objective standards is expressed by the following formula: -1 m0ol
formula: P - the focal length of the objective standard device, when the support microscope is, D (-) - material refractive index:
R - spherical diameter, mm;
s - standard length, mm
The conversion between the optical power of the objective standard device and the focal length of the lens is given by the following formula: H
91+0.001h
where: - the distance between the lens point and the cornea point is 12mm(1)
The objective standard device consists of a concave lens (whose spherical surface is like the human cornea) and a rectangular piece with a half-surface or a half-surface. It is connected together: there is a blue spot on the retina, which is the same as the human eye! , the source type weighing belt is used to determine the preset value reading error of the objective electric ophthalmometer, the total uncertainty of the objective standard instrument is 0.7-0.10 D
subjective standard instrument
type standard can be connected with the purchased focal change standard to form a three-dimensional standard instrument. The total uncertainty of the top-level indication error of the subjective ophthalmometer and the card view standard is 0.04 T,
2 Technical requirements
1 Appearance
【, 1 The weight of the ophthalmometer should be complete, and the external standard of the ophthalmometer should be marked with the standard of the degree of accuracy, JJG 922-1596
Objective standard consists of 11 pieces of 0, ±2.5, 15, ±10, 115, =20D, and objective standard consists of 8 pieces of 12.5, ±5, -10, 115D. 1.2 The installation of the standard should be firm and not loose or fall off: 1.3 The surface of the standard should not have obvious spots, scratches, pits, bubbles and other defects. 1.4 The standard should not have defects such as debonding and speckle reflection. 2 Objective standard
The annual change of the objective standard group within the range of -10 should not exceed 0.06D, and the annual change within the range of more than 101 should not be shorter than 0.103 Subjective test standard
3.1 The annual change of the pre-focus measurement of the subjective standard should not exceed 2.02D. 3.2 The zero vision error of the single hyperopic unit of the subjective standard instrument should not exceed 2.021. 3. Verification conditions
4. Verification environment
Temperature (20 ± 2) ℃, relative humidity <85%, the time for the standard instrument to be tested to be in the indoor temperature balance should not be less than 21. The time for the calibration instrument to be in the indoor temperature balance should not be less than 245. Cooling conditions Www.bzxZ.net
5.1 Use a 0.01D reference ophthalmometer (hereinafter referred to as ophthalmometer) to calibrate the objective standard instrument. The standard uncertainty of the ophthalmometer should be less than or equal to 0.0031 in the range of 0~±0D, and less than or equal to 0.05D in the range of 10D, and should be calibrated by the ophthalmometer. 5.2 Use a 0.01D working standard focus meter (hereinafter referred to as focus meter) to calibrate the subjective standard instrument. The standard uncertainty of the focal length measuring plate shall be less than or equal to 0.005, and shall be calibrated with the pre-focus reference lens group. 5.3 The objective standard shall be tested with a collimated light source with a focal length of not less than 1m. IV. Verification Items and Verification Methods
6 Appearance Inspection
6, 1 Visually observe the focal length of the optical instrument to be tested, which shall comply with the provisions of Section 1. 6.2 Insert the objective standard into the connection mechanism, and roughly observe the reflected light spot of the standard through the display screen of the optometrist. No other light spots other than the focused light spots shall appear. To verify the focal length and annual variation of the objective standard, install the connection mechanism on the forehead support of the optometrist and tighten the fixing screws. Make the connection mechanism parallel to the measuring hole of the optometrist, and put the tested standard into the socket of the connection mechanism. Move the ophthalmometer left and right, forward and backward to adjust the focus, so that the optical center of the standard is located in the center of the ophthalmometer display screen, and focus to the clearest point: read the value of the standard's focal length directly from the display. At least 3 effective values ​​are read for each standard, 41, 4 and =: their average value is 4(a+2-")/3, and then the static positive value of the ophthalmometer itself is added to get the actual value of the standard: 2
J.H922—1996
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The deviation between the actual value of the standard under test and the last calibration value shall comply with the provisions of Article 2. For the case where the calibration time is less than 1 year or more than 1 year, the annual change shall be calculated according to the deviation between the actual value this time and the last calibration value, and shall also comply with the provisions of Article 2. 8 Subjective standard vertex power The annual variation is based on the reverse placement (i.e., the position of the lens) of the subjective standard to be tested on the lens support seat of the focal meter. After the optical center of the standard is moved to coincide with the optical axis of the focal meter, the focal value of the top of the standard is obtained from the small screen. Each standard is read up to 3 values, ,, and: the average value = [,! )3, and then add the correction value of the focal meter itself: the actual value of the standard is obtained = fb.
The actual value of the standard to be tested is the deviation from the last calibration value. If the calibration period is not 1 year or exceeds 1 year, the annual variation is also The calculation of the deviation between the actual value and the last specified value shall comply with the provisions of Article 3.1: 9. Verification of the zero-diaphragm error of the telescope. Install the telescope wide tube on the V-shaped workbench of the optical fixture, and adjust the telescope on the left to make the optical axis coaxial with the parallel light tube of the optical fixture. Then adjust the eyepiece of the telescope to make the current porcelain mirror scale plate clear. Then adjust the diopter of the near-vision telescope to make the pattern of the resolution plate on the focal plane of the lower half of the optical fixture tube form an image on the graticule plate 1 of the telescope. At this time, record the reading of the telescope and repeat the measurement 3 times. , the average of the three readings shall not exceed the provisions of Article 3.2. V. Verification Result Processing and Verification Period
1. The objective standard and objective standard that meet the requirements of this regulation shall be issued a verification certificate. 11. Newly manufactured subjective and objective standards shall be deemed unqualified if they do not meet any of the technical safety requirements of this regulation after inspection. If the objective standard in use does not meet the provisions of Article 6.2, it is allowed to be repaired and used again after passing the verification. For unqualified standards, a verification notice shall be issued and the use shall be prohibited. 12. The verification period of optometry false focal length standard is 1 year 3
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