The mobile version of BNS-94 Radiation Portal Monitor was developed to serve as a high-sensitivity device for reconnaissance gamma contamination. The two detectors of the BNS-94MH is a scintillation probe with high sensitivity for gamma radiation. A patented measurement method assures background, shielding, and speed compensation in one single detector. The optionally connected computer receives data from the detectors in every half seconds then calculates the actual alteration from the average background level. If the difference exceeds the presets value the fix version sends an online, the mobile version a light alarm signal.