仪器本底

为减小光电倍增管暗电流和放大器栅流产生的仪器自身本底，设计了随温度变化的自动补偿电路。

In order to reduce the background resulting from the dark current of the photomultiplier and the grid current of amplifer , a special design of auto-compensation circuit is provided .

该项新技术主要包括高压钢瓶采样、高真空低漏率的进样系统、降低仪器系统的本底与漏率、防止实验室环境波动等内容。

The technique includes sampling using high pressure steel vases , injecting samples under the conditions of high vacuum and low seepage rate , reducing background values of the instrument and preventing the fluctuation of the environment of laboratory .

通过对仪器的刻度、本底实验、γ点源实验、加入标准样品实验等，确定了该方法的探测下限为每包废物中~（235）U含量0.053g。

The lower detection limit is settled on 0 . 053 g 235U for each package of waste through a series of tests on scale , background , r-point source and reference samples .