Measuring Instrumentsfor γ-Ray Exposure

JJG 2044-1989 γ-ray exposure meter calibration system JJG2044-1989 standard download decompression password: www.bzxz.net
This calibration system is applicable to the calibration of γ-ray therapy level and protection level exposure meter metering instruments. The procedure of transferring the C·kg-1 unit value from the γ-ray exposure standard to the working metering instrument through the standard exposure meter, and specifying its uncertainty and calibration method.

National Metrology Verification System of the People's Republic of China JJG2044--89
Y-ray Exposure Measuring Instruments
Approved on September 11, 1989
Implementation on July 1, 1990
State Bureau of Technical Supervision
Verification Scheme of Measuring Instrumentsfor of Y-ray Exposure
JJG 2044---89
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This national metrology verification system was approved by the State Bureau of Technical Supervision on September 11, 1989, and implemented on July 1, 1990. Drafting unit:
China National Institute of Metrology
The drafting unit is responsible for interpreting the technical provisions of this verification system. The main drafters of this verification system are:
Wang Xiaolan
Zhang Zhibin
(China National Institute of Metrology)
(China National Institute of Metrology)
Metrology reference instruments
: metrology standard instruments.
Working measuring instruments
Four 丫Radiation dosimeter measuring instrument verification system block diagrama*
Bone in bone, bone in operation, quantity pulse
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JG2044---89
Total 3 pages, page 1
?Radiation dosimeter verification system
This verification system is applicable to the verification of?Radiation treatment level and protection level dosimeter measuring instruments. The?Radiation dosimeter standard transmits C. Kg-1 unit value to the working measuring instrument through the standard dosimeter, and specifies its uncertainty and verification method. I. Measurement standard instrument
1 Purpose of national measurement standard
?Radiation dosimeter is widely used in radiation work in industry, agriculture, medicine, scientific research and other fields. In order to ensure the accuracy and consistency of the measurement and make the values ​​used by each unit traceable, a?Radiation dosimeter standard is established. It reproduces the exposure unit Ckg- strictly according to the definition. Through the order of the verification system table, the exposure value can be accurately passed down from the national standard (within the specified error range) to ensure the accuracy and uniformity of the value. 2 The name of the complete set of main metrological instruments that make up the national metrological standard: The X-ray exposure standard device mainly consists of the following three parts: 2.1 Graphite cavity ionization chamber
2.2 Ionization current absolute measurement system
2.3 X-ray irradiation field
3 The range of the value reproduced by the national metrological standard
r X-ray: 2.58×10-7-2.58×10-1C.kg-14 The total uncertainty of the national metrological standard
X-ray: ±=土0.62% (confidence probability is 95%, the same below). 2. Measurement standard instruments
5 Standard exposure meter measurement range: 2.58×10-7~2.58×10-1C.kg-1 Standard exposure meter total uncertainty: ±6=±1.5% (treatment level)~±5% (protection level).
Tool 3 pages
Page 2
3 Working meter instruments
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J3G2344--89
6 Working level exposure meter measurement range: 2.58×10-7~2.58×10-1C.kg-i.
Working level exposure meter total uncertainty is ±. 1 ±2.5% treatment level! ±15% (protection level).
Four-Ya Radiation exposure meter measurement instrument calibration system block diagram? Radiation exposure meter measurement instrument calibration system block diagram meter
Working measuring instrument
Ya Radiation exposure reference device
±0=±0.62%
2.58 ×10-7 ~2.58 ×10~1
Standard exposure meter
±=±1.5%±5%
2.55×10 7~2.58×10-1 C.kg1
Substitution method or direct comparison method
Exposure meter
#-±2.5%±15%
2. 58X 10°-7 2.58X10-1 C- kg-1JJG2044--89
1. Substitution method
Total 3 pages Page 3
The instrument calibration of X-ray exposure is to place the probe of the instrument to be tested at a point in the known radiation field measured by the reference ionization chamber or the standard exposure meter. Then measure, compare the measurement result with the reference value or standard value, and finally give the calibration factor of the instrument to be tested. 2. Direct comparison method
Put the ionization chamber of the working-level exposure meter to be tested and the ionization chamber of the standard exposure meter at the same time at a certain position in the uniform radiation field, read the readings of the two exposure meters, and then compare them. Finally, give the calibration factor of the instrument to be tested. 3. Requirements for calibration equipment
The uncertainty of the calibration result depends on the uncertainty of the standard used, the inherent error of the instrument to be tested and the transmission error of the calibration equipment
According to the transmission process shown in the calibration system block diagram. The cumulative error is calculated by the square root method. The requirements for the calibration device are as follows:
1 First-level transfer
The transfer error of the first-level calibration device is 0.93% (for instruments of protection level, it should be 3.9%).
2 Second-level transfer
The transfer error of the second-level calibration device is 1.5% (for protection instruments, it should be 10%). The People's Republic of China
National Metrology Verification System
Y-ray Exposure Quantity Meter
JJG2044--89
Developed by the State Administration of Technical Supervision
Published by China Metrology Press
No. 2, Pingguo West Street, Beijing
China Printed by Yinjuguang Publishing House
Published by Beijing Publishing House of Xinhua Bookstore
Format 850×1168/92
1990 1st edition
Standard book number 155026278
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Printing sheet 0.25 Words 4,000
1st gray printing in April 1990
Standard new book list: 140-0708
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