为解决GP-1型γ射线谱仪能谱漂移的问题,在前置放大器与主放大器之间加一个螺旋电位器,使之可手动连续调节信号幅度,确保谱仪在运行中系数不变。叙述了B-γ-γ能谱法测铀、镭、钍的原理及含量的计算公式,并用改进了的GP-1型γ射线谱仪测定了铀镭平衡破坏样品中的铀,镭、钍含量。本工作相化学方法分析的结果是符合的。 In order to solve the spectral shift of the GP-1 γ-ray spectrometer, a spiral potentiometer is added between the preamplifier and the main amplifier so that the signal amplitude can be manually and continuously adjusted to ensure that the spectrometer has the same coefficient during operation. The calculation principle and content of uranium, radium and thorium in B-γ-γ spectrometry are described. The uranium, radium and thorium in the uranium-radium balance destroyed sample are measured by a modified GP-1 γ-ray spectrometer content. This work phase chemistry method analysis results are in line.