Reference device and method capable of stably regulating radon exhalation rate

Abstract

Provided is a reference device and method capable of stably regulating radon exhalation rate. The reference device includes a water platform, a gas-flow radon seed, an air pump and a regulation chamber are arranged outside the water platform, the gas-flow radon seed is arranged between the air pump and the regulation chamber, the air outlet end of the gas-flow radon seed is connected to the air inlet end of the air pump, the air inlet end of the gas-flow radon seed is connected to the air outlet end of the regulation chamber, a radon exhalation outlet and a radon reflux inlet are formed in thetop of the water platform, when a radon collecting chamber is turned over on the top surface of the water platform, the radon exhalation outlet and the radon reflux inlet can be covered by the radoncollecting chamber, the air outlet end of the air pump is connected with the radon exhalation outlet, the air inlet end of the regulation chamber is connected with the radon reflux inlet, and the regulating of the radon exhalation rate is achieved by adjusting the chamber volume of the regulation chamber. According to the reference device, the radon exhalation rate is regulated by changing the inner cavity volume of the regulation chamber, a large number of standard radon seeds with different source intensities do not need to be purchased, the structure is simple, the calculation process is also simpler, and the purchase costs in the earlier period and the management and maintenance costs in the later period are also lower.

Description

technical field [0001] The invention relates to the technical field of nuclear radiation detection, in particular to a reference device and method capable of stably regulating the exhalation rate of radon. Background technique [0002] To test the accuracy and reliability of the radon measuring instrument, it is necessary to use a radon exhalation rate standard device that is not subject to changes in the temperature, humidity and air pressure of the environment. All radon meters need to be calibrated with standard devices before use, and should be calibrated regularly with standard devices during daily use. [0003] The Chinese invention patent with the patent number "201310483616.4" discloses a method and device for arbitrarily adjusting the radon exhalation rate and effective decay constant, which is used to test the accuracy and reliability of the radon measuring instrument, which has basically the same function as the standard device Effect (the specific structure of t...

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Problems solved by technology

[0005] Although the above-mentioned reference device 1 and reference device 2 can both detect the accuracy and reliability of the radon measuring instrument, they still have the following defects in practical application: 1. Reference device 1 and reference device 2 are all obtained by replacing different sources. A strong solid radon source (standard radon source) is used to adjust the radon exhalation rate, but the price of the standard radon source is relatively high, and the purchase cost is expensive

If it is necessary to adjust the radon exhalation rate in a wide range, many standard radon sources with different source intensities will be used. The storage, management and maintenance of these standard radon sources with different source intensities will require a lot of manpower and material costs in the later stage.

2. In general, when the radon exhalation rate is constant, both reference device 1 and reference device 2 adjust the effective decay constant λe (the effective decay constant is the sum of radon decay constant, leakage and back diffusion constant) To adjust the radon concentration, the structure of the whole device is complicated, and the calculation process is also relatively complicated

3. Due to the existence of leakage (in the reference device 2, pumping air to the outside of the radon collector through a micropump can also be regarded as "leakage") (reference devices 1 and 2 mainly adjust the leakage constant to change the effective decay constant value), the above reference The process of increasing the radon concentration in the radon collection room by devices 1 and 2 takes a long time, and the efficiency of calibrating the radon meter needs to be improved

4. In the above-mentioned reference devices 1 and 2, although the radon collecting chamber is flatly buckled on the panel, the patentee believes that there is no leakage between the two, but in the actual processing of the radon collecting chamber and the panel, due to the limitation of processing accuracy, A completely flat seal cannot be achieved between the two, that is, there will still be a slight gap between the two, resulting in leakage, which will lead to deviations in test results

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