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 sensitivity and isotope identification, Scintillation detectors (NaI/Tl) are preferred. Ensure the device has a measurement range suitable for your needs (typically from 0.01μSv/h to 100mSv/h) and an accuracy tolerance of ±15% or better. Additionally, look for features like real-time dose rate display, cumulative dose tracking, and adjustable alarm thresholds for safety.