一、引言γ射线料位计作为一种基本的同位素仪表,在我国建材、冶金、化工、煤炭等行业已经得到广泛应用。目前我国各行业使用的γ射线料位计,大多数都采用G-Mγ计数管作为探测元件。其主要原因之一是比用碘化钠闪烁体作为探测元件造价低。但是,由于γ计数管探测效率较低,这类料位计所配用的辐射源活度比较大。1987年10月,我们对前五年我国生 I. INTRODUCTION As a basic isotope meter, γ-ray level meter has been widely used in China’s building materials, metallurgy, chemical industry and coal industries. At present, the γ-ray level meters used by various industries in China mostly use the G-Mγ counter tube as the detection element. One of the main reasons is lower cost than using sodium iodide scintillator as the detection element. However, due to the low efficiency of gamma counter detection, these level gauges are equipped with a relatively high activity of the radiation source. In October 1987, we were born in our country for the first five years