C.5 calibration and verification – Fluke Biomedical 10100AT User Manual

Page 72

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10100AT
Operators Manual

C-4

C.5 Calibration and Verification

Calibration or calibration verification is performed by comparison of each 96035B ion chamber with a
reference chamber calibrated at either the National Institute of Standards and Technology (NIST) or PTB.
Specifications for all PTB equivalent beam qualities are given in the tables in the energy correction factor
section.

Standard Calibration

The standard calibration is performed at one diagnostic and one mammographic beam quality as given
below. Calibration factors are normalized to 22°C and 1013 hPa of atmospheric pressure.

Diagnostic Unattenuated beam: Calibration is performed at the Fluke Biomedical, Radiation
Management Services equivalent of L100 (NIST defined as 100 kVp, first HVL of 2.8 mm Al,
homogeneity coefficient of 59).

Mammographic beam: Calibration is performed at the Fluke Biomedical, Radiation Management
Services equivalent of MoMo28 (NIST defined as 28 kVp, first HVL of 0.332 mm Al, homogeneity
coefficient of 74.3).

European Calibration Option

This calibration option replaces the standard calibration for units sold in Europe, or when specifically
requested by a customer. This option includes one diagnostic and one mammographic beam quality, 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).

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%.

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