RJ31-1305 personal dosimeter is equipped with a large geigmiller (GM) counter tube with ultra-high sensitivity for radiation detection. The instrument adopts new adaptive filtering algorithm, which makes the product has excellent performance in both measuring accuracy and response speed. RJ31-1305 measures dose-equivalent rate and cumulative dose at the same time. Users can set dose-equivalent (rate) alarm thresholds for different applications. When the measured data exceeds the set threshold, the instrument automatically generates an alarm (sound, light or vibration). The monitor adopts high performance and low power processor, with high integration, small size and low power consumption.