Specifications
18
Procedure (Metric Units)
1. Power on the Inspector EXP. Make sure the Inspector EXP is in Timed Count (Total/Timer) mode
displaying COUNTS.
2. Place the Inspector EXP in the locaon where the eciency calibraon will be performed and take a
count of at least 10 minutes. Mulply the acquision me by 60 to convert it from minutes to seconds.
Divide the total number counts by the acquision me (in seconds) to calculate the background counng
rate (RB) in cps. Record this value.
3. Center the source 1 cm from the end window of the Inspector EXP’s external probe (the small radiaon
symbol on the back of the probe marks the center of the detector) and take a count of at least 1 minute.
Divide the total number of counts by the counng me (in seconds) to calculate the gross count rate
(gcps or RG).
4. Calculate the eciency using the following equaon:
Where
E is instrument eciency in counts per disintegraon
RG is the gross count rate in counts per second (cps)
RB is the background count rate in cps
A is the acvity of the source in disintegraons per second (dps) or
becquerels (Bq)
5. Repeat Steps 3 and 4 for addional radionuclides.
6. If you would like to record eciency values in the Inspector EXP’s memory for any of the supported
radionuclides (S-35, Sr/Y-90, Cs-137, P-32, C-14, I-131, Co-60, ALPHA), connue with the following steps.
7. Connect the Inspector EXP to the PC running Observer USB using the USB cable. An applicaon window
for the Inspector EXP should open within a few seconds.
8. Display the control panel by clicking View|Cal Panel.
9. Enter the updated eciencies in the appropriate elds.
10. If you would like the Inspector EXP to display in acvity units (i.e., DPM) for a specic source instead of
the count rate (CPM), select it from the Applied Isotope dropdown box. Otherwise, leave as None (cpm/
cps).
11. When all relevant values have been updated, click the Update Sengs buon. Aer a second or two
the Inspector EXP should beep to acknowledge receiving the updated sengs.