This model 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, and set computer alarms.
Detector
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.).
Operating Range
mR/hr – .001 (1µR) to 100
CPM – 0 to 350,000
µSv/hr – .01 to 1000
CPS – 0 to 5000
Total Counts- 1 to 9,999,000 counts
Accuracy (Referenced to Cs137)
Typically ±15% from factory, ±10% with NIST Source Calibration
Energy Sensitivity
Detects Alpha down to 2 MeV. Detects Beta down to .16 MeV; typical detection efficiency at 1 MeV is approx. 25%. Detects Gamma down to 10 KeV through the detector window. 3340 CPM/mR/hr (137Cs). Smallest detectable level for 125I is .02 µCi at contact.
Built-In Efficiencies
Sulfur (35S), Strontium (90Sr/y), Cesium (137Cs), Phosphorus (32P), Carbon (14C), Iodine (131I), Cobalt (60Co), and Alpha
Selectable Alert Set Range
mR/hr .001 – 100 and CPM 1 – 350,000. Pulsating beeper sounds the alert. Adjustable alert levels are used for mR/hr / CPM, and µSv/hr / CPS. 70db @ 1m. Alarm will sound when in Timer Mode when set alarm threshold is reached.
Anti-Saturation
Meter will hold at OVER RANGE in fields as high as 100 times the maximum reading.
Averaging Periods
Display updates every 3 seconds. At low background levels, the update is the average for the past 30-second time period. The timed period for the average decreases as the radiation level increases.
