Fluke Biomedical TNT 12000 - Manual (Page 98)

TNT 12000
Users Manual
A-4
Unattenuated beam............................................... Calibration is performed at the Fluke Biomedical, Radiation
Management Services equivalent of DV70 (PTB defined as 70 kVp and
first HVL of 2.45 mm Al).
Attenuated beam................................................... Calibration is performed at the Fluke Biomedical, Radiation
Management Services equivalent of DH70 (PTB defined as 70 kVp
and first HVL of 6.77 mm Al).
Other Calibration Options
Optional calibration points are the Fluke Biomedical, Radiation Management Services
equivalent of L100, M50, S75, 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
Attenuated Beam (Behind the Phantom)
The energy correction factors for the 96020C are determined for the attenuated diagnostic
beam using the PTB defined DN series of beam qualities given in Table A-1.
Table A-1. Specifications for PTB Defined Attenuated Beam Qualities
PTB
Denomination
kVp
Added Filtration
in mm AI
First HVL in mm
AI
First HVL in mm
Cu
DN40 40 6.5 2.2 0.07
DN50 50 12.5 3.4 0.123
DN60 60 18.5 5.0 0.207
DN70 70 23.5 6.2 0.289
DN80 80 29.5 7.8 0.403
DN90 90 32.5 9.0 0.501
DN100 100 36.5 10.1 0.609
DN120 120 42.5 12.0 0.839
DN150 150 52.5 14.1 1.245