Radiation Alert Inspector + Manuel D'instructions page 17

To check a surface, hold the detector window close to the surface and read the
count rate (wait 30 seconds or until the reading has stabilized). If you want to find
out if a surface is slightly radioactive, take a timed count or a longer accumulated
count.
5 Maintenance
The Inspector+ requires regular calibration and careful handling to assure good
measurements. Use the following guidelines to maintain the Inspector+ properly.
Calibration
The Inspector+ should be calibrated as often as your regulations require, or in any
case, at least once a year. The best way to calibrate is using a calibrated source.
If no source is available, it is possible to calibrate electronically using a pulse
generator.
The standard radionuclide for calibration is Cesium-137. A certified calibration
source should be used. To calibrate the Inspector+ for another radionuclide, you
must use a calibrated source for that radionuclide or the appropriate conversion
factor referenced to Cs-137.
CAUTION: Errors can occur when using low level sources or background to set
CAL factor. In the Calibration mode, the smallest increment which can be
adjusted is .010, which prevents fine adjustment of the CAL factor.
Calibrating Using a Source
1. Place the Inspector+ or Inspector+ EXP probe at a distance from the source
that corresponds to a 50 mR/hr field with the detector window facing the
source.
2. Set the Inspector+ mode switch to mR/hr.
3. Turn the Inspector+ on.
4. Open the source and record 20 consecutive readings.
5. Close the source.
6. Calculate the average of the readings and record.
a) If the average is ± 10% of 50 mR/hr, go to Step 7.
b) If the average is not ± 10% of 50 mR/hr, go to Step 10.
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