Thermo Scientific SAM12, Руководство пользователя

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Issue: 1.0 Calibration Procedure
Thermo Fisher Scientific SAM12 User Manual 10-3
At the end of the calibration, the user is prompted to PASS or
FAIL the calibration. If the result does not appear to be correct
– see below for reference values – it may be appropriate to
FAIL (or Cancel) the calibration.
SAM12A
No. detectors
60
Co (1.2 MeV)
137
Cs (662 keV)
137
Ba (356 keV) CCM
3 inches Centre 3 inches Centre 3 inches Centre Centre
4C
42%
(40-44)
38%
(36-40) 17%
(16-20) 16%
(15-19) 28%
(26-31) 26%
(24-28) 0.4%
6C
57%
(55-59)
53%
(51-55) 24%
(22-26) 23%
(21-25) 38%
(36-40) 36%
(34-38) 1.1%
See
Specification (page 3-1) for more information regarding the
various SAM12 types.
NOTES: If the efficiency is very different from the expected
value and the background is stable, perform an HV scan (see
Performing the HV Scan (page 9-4)
) and repeat this
procedure.
The Instrument Configuration Report (See
Reports (page 5-
31)
) will provide a hard copy of the set-up and calibration
results.
Calibration for Other Nuclides
See HV Scan (page 5-25) for more information.
Efficiency factors for other nuclides and mixtures of nuclides
can be defined in a similar manner to that for
60
Co described in
Preparation for Calibration (page 10-2 . )Before calculating
efficiency factors for new nuclides, it would be advisable to
verify those for
60
Co and / or
137
Cs, ensuring that the SAM’s
detectors are functioning correctly.
If low energy nuclides need to be monitored such as
57
Co, then
it may be necessary to undertake an HV scan for that particular
nuclide. Follow the procedure described in
Performing the HV
Scan (page 9-4) , specifically for the Figure of Merit method
(see Figure of Merit (FOM) method (page 9-5) ), in order to find
the best operating voltage.
If NBR is required, then the voltage must always be optimised
using the method described .in
NBR method (page 9-5) .