When sourcing portable radiation detectors, the most critical technical factor is the sensor type. Geiger-Muller (GM) tubes are the industry standard for general detection of Alpha, Beta, and Gamma rays due to their cost-effectiveness. For higher precision and isotope identification, Scintillation detectors (NaI/CsI) are preferred. Buyers must verify the measurement range (typically from 0.01μSv/h to 10mSv/h) and the energy response to ensure the device accurately detects radiation across different energy levels. Additionally, look for a fast response time (<2 seconds) and a high sensitivity rating to ensure user safety in fluctuating environments.