METHOD AND DEVICE FOR MEASURING RADON BY ELECTROSTATIC COLLECTION WITHOUT INFLUENCE OF ENVIRONMENT TEMPERATURE AND HUMIDITY

摘要

A method and device for measuring radon by electrostatic collection without influence of environmental temperature and humidity. The device comprises a measuring cavity (1), a semiconductor detector (2), a high-voltage module (3), a sampling pump (4), a vacuum meter (5) and a regulating valve (6), wherein the regulating valve (6) is arranged on the air inlet channel of the cavity; the vacuum meter (5) and the sampling pump (4) are arranged on the air outlet channel of the measuring cavity in sequence; the semiconductor detector (2) is arranged on the upper part inside the measuring cavity and connected with one interface end of the high-voltage module through a wire, and the other interface end of the high-voltage module is connected with the shell of the measuring cavity through a wire. The method, achieved by reducing air pressure in the electrostatic collection measuring cavity below a certain threshold value, can make the efficiency of collecting positively charged ²¹⁸Po particles on the surface of the detector by the electrostatic collection measuring cavity basically unchanged when the relative air humidity of external environment is changed from 0% to 100% in the working temperature range of 0 to 45 degrees, thereby the detecting efficiency is not changed with the change of temperature and humidity of the external environment, and the threshold value is related to a geometric factor of the measuring cavity and the electric field intensity distribution in the measuring cavity.