在用正比计数管进行氚测量时,通常用CH4作为计数气体,将其与He按比例配制成一系列的混合气体,充入计数管进行计数测量,研究He对正比计数管测量性能的影响。在此基础上,配制了含有He的3H样品进行实际测量,得到的测量结果与预期值相符。实验表明,He的存在会改变计数管的坪特性,当体积浓度低于10%时,这一影响可以忽略。 When tritium is measured with proportional counter, CH4 is usually used as the counting gas, which is then mixed with He to form a series of mixed gas. The counting tube is filled with counting gas to study the influence of He on the measuring performance of proportional counter tube. On this basis, 3H samples containing He were prepared for actual measurement, and the measurement results obtained were in line with the expected values. Experiments show that the presence of He changes the flatness of the counting tube. When the volume concentration is less than 10%, this effect can be neglected.