Siemens AG SPR2-310.842.01.07.02 ARCADIS Varic / Orbic
12.06 CS SD 24
Adjustments 21
Page 21 of 34
Medical Solutions
Dose area product 2.8
DAP chamber test (Wellhöfer) / DAP chamber adjustment (PTW)
1. Decide which DAP chamber is installed, “Wellhöfer” or “PTW”, see path <Main Sys-
tem>-<Configuration>-<Options>.
¹ DAP camber resolution 0.01cGy cm*cm = “Wellhöfer” DAP
¹ DAP camber resolution 1.0 cGy cm*cm = “PTW” DAP
2. Continue with the corresponding description “Wellhöfer...” or “PTW...”.
NOTE
A chamber gain adjustment is necessary if the DAP accuracy
check or the air kerma accuracy check is not in tolerance.
Wellhöfer - chamber gain adjustment
1. Register an emergency patient to allow radiation release.
2. Select dose rate for air kerma or dose for DAP, depending on the configuration, at the
external dose meter.
NOTE
Make sure that 2.5mm AL filtration at the external dose meter is
selected during the chamber gain adjustment.
3. Attach the small dose measurement chamber (1cm
3
) into the center of the I. I. grid.
4. Select I.I. full format and open the collimator X-iris and the slot diaphragm to the maxi-
mum position.
5. Select the following exam set to get as a result the HC2 control curve:
¹ Ortho/Trauma; Standard; Body reg = HIP; Fluoroscopy
X 6. Briefly release fluoro, select the <kV STOP> key and 70 kV with the kV + / - buttons on
the console.
X 7. Release fluoro and compare the dose rate from the external dose meter to the internal
monitor display.
¹ Use correction factors and calculations described under “DAP accuracy check” or
under “Air kerma accuracy check”.
¹ Calculate the external dose meter's deviation from the internal monitor dis-
play.Difference = [(int. value) - (ext value)] / (ext value)
¹ The maximum allowed difference is ± 0.25 (± 25%).
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