Radiation Detection

Radiation Alert Ranger a ß y x

SE International's Ranger offers maximum performance in a lightweight, rugged solution for surveying at the facility or in the field. The Ranger has been designed for industrial environments, but it still has all of the features you’ve come to love in the lab. The Ranger is a small, handheld, microprocessor-based instrument which offers excellent sensitivity to low levels of alpha, beta, gamma, and x-rays and has built in efficiencies for common isotopes to calculate activity in Bq and DPM. It has a backlit digital display, a red count light, and a beeper that sounds with each count detected. Other features include selectable alert levels, an adjustable timer, and an optional wipe test plate for swipes. Internal memory and the free Observer USB Software allow you to download your data, set computer alarms, and calibrate your instrument!


Internal Halogen-quenched, uncompensated GM tube with thin mica window, 1.4-2.0 mg/cm2 areal density. Effective diameter of window is 45 mm (1.77 in.).

Averaging Periods

Display will update every 3 seconds. At low background levels, the update is the moving average for the past 30-second time period. The timed period for the moving average decreases as the radiation level increases.

Operating Range

  • mR/hr - .001 (1µR) to 100
  • CPM - 0 to 350,000
  • µSv/hr - .01 to 1000     CPS - 0 to 5000 Total/ Timer - 1 to 9,999,000 counts


(Referenced to Cs137) Typically ±15% from factory, ±10% with NIST Source Calibration


140 X 68 X 33 mm (5.5 X 2.7 X 1.3 in)

Energy Sensitivity

  • 3340 CPM/mR/hr referenced to Cs137
  • Detects Alpha down to 2 MeV.
  • Detects Beta down to .16 MeV; typical detection efficiency at 1 MeV is approximately 25%
  • Detects Gamma down to 10 KeV through the end window. Smallest detectable level for I125 is .02 µCi at contact.

Built-In Efficiencies

35Sulfur (S35), 90Strontium (Sr/y90), 137Cesium (Cs137), 32Phosphorus (P32), 14Carbon (C14), 131Iodine (I131), 60Cobalt (Co60), and Alpha


*Ranger XP with External Probe pictured