Gamma Radiation Detectors: Rent or Buy

Gamma surveys primarily measure external exposure (dose rate). Surface contamination surveys require the right probe type and geometry — a dose rate survey alone won't tell you if a surface is contaminated.

Confirm the dose rate range you expect to encounter, the isotopes of concern (this affects whether you need energy-compensated detection), whether you need dose rate only or accumulated dose as well, and applicable regulatory standards. Also confirm whether intrinsic safety or special certifications are required for your work environment. Our Rangers use uncompensated GM tubes calibrated to Cs-137. If your program requires energy-compensated dose-equivalent readings, call us first.

Dose-rate readings depend heavily on geometry, distance, and shielding between you and the source. A single reading at one point doesn’t represent full-shift exposure. Survey systematically, document your distance from sources, and use readings to set work boundaries rather than as a single pass/fail number.

Hold the window close to the source without touching it. If a sheet of paper between the window and the source stops the reading, it's most likely alpha. If about 3 mm (1/8 in.) of aluminum stops or reduces it, it's most likely beta. Gamma passes through both. Most isotopes emit both beta and gamma, so expect the reading to drop rather than stop.

Yes, for finding a source. The Ranger typically detects about 2 ft into a pile. Use fast-response mode, move slowly and follow the higher readings or clicks toward the source.