Fluke Biomedical TNT 12000 - Manual (Page 106)

TNT 12000
Users Manual
B-4
Diagnostic Unattenuated beam ........................... Calibration is performed at the Fluke Biomedical, Radiation
Management Services equivalent of DV70 (PTB defined as 70 kVp,
first HVL of 2.45 mm Al).
Mammographic beam ........................................... Calibration is performed at the Fluke Biomedical, Radiation
Management Services equivalent of MV30 (PTB defined as 30 kVp,
first HVL of 0.337 mm Al).
PTB Calibration Option
This calibration option replaces the standard calibration when PTB requirements must be
met, or when specifically requested by a customer. This option includes two diagnostic
points and one mammographic point as given below. Calibration factors are normalized
to 20 ° C and 1013 hPa of atmospheric pressure.
Diagnostic Unattenuated beam ........................... Calibration is performed at the Fluke Biomedical, Radiation
Management Services equivalent of DV70 (PTB defined as 70 kVp,
first HVL of 2.45 mm Al).
Diagnostic Attenuated beam ............................... Calibration is performed at the Fluke Biomedical, Radiation
Management Services equivalent of DH70 (PTB defined as 70 kVp,
first HVL of 6.77 mm Al).
Mammographic Beam........................................... Calibration is performed at the Fluke Biomedical, Radiation
Management Services equivalent of MH30 (PTB defined as 30 kVp,
first HVL of 0.67 mm Al).
Other Calibration Options
Optional calibration points are the Fluke Biomedical, Radiation Management Services
equivalent of M50, S75, H60, MoMo35, DV30, DV40, DV50, DV60, DV80, DV90,
DV100, DV120, DV150, DH40, DH50, DH60, DH80, DH90, DH100, DH120, and
DH150. Calibration factors at these points may be normalized to either 20 ° C or 22 ° C, as
specified by the customer.
Calibration Accuracy
NIST Traceable ...................................................... NIST traceable reference chambers are accurate to within ± 1 % at
each beam quality. Matching between the reference and unknown
chamber is accurate to
± 1 %. Thus, NIST traceable calibrations are
accurate to within ± 2 %.
PTB traceable ........................................................ PTB traceable reference chambers are accurate to within ± 1.5 % at
each beam quality. Matching between the reference and unknown
chamber is accurate to
± 1 %. Thus, PTB traceable calibrations are
accurate to within ± 2.5 %.
Calibration Verification
NIST traceable ....................................................... For NIST traceable calibrations, a chamber will be reported to be
outside of its calibration accuracy specification when a new calibration
value differs from the old calibration value by more than
± 4 %. This
includes the ± 2 % accuracy specification plus ± 1% for the verification
reference plus ± 1 % for the verification match.
PTB traceable ........................................................ For PTB traceable calibrations, a chamber will be reported to be
outside of its calibration accuracy specification when a new calibration
value differs from the old calibration value by more than
± 5 %. This
includes the ± 2.5 % accuracy specification plus ± 1.5 % for the
verification reference plus ± 1 % for the verification match.
Energy Correction Factors
Diagnostic – Unattenuated Beam (In Front of the Phantom)
The energy correction factors for the 96035B are determined for the unattenuated
diagnostic beam using the PTB defined DV series of beam qualities given below in Table
B-1.