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MAMMOMAT Novation DR
SPB7-250.815.06.02.02
Siemens AG
12.05
CS SD 24
Page 72 of 116
Medical Solutions
Gain calibration
The detector captures charge in its TFT, which is then carried as an electronic signal
through charge amplifiers and analog-to-digital conversion to generate a digital signal.
While the charge amplifiers are matched, small differences in their performance can result
in differences in the X-ray densities detected for the same amount of X-ray.
Performing calibration allows the system to detect these small differences, along with
other variables that can affect the digital signal output. The system can then apply adjust-
ments to the output data to compensate for these differences.
When is it necessary to perform the gain calibration of the detector
The gain calibration of the detector must be performed
•
every two weeks (a pop-up draws the user’s attention to this). Once a week is recom-
mended.
NOTE
Perform the gain calibration only if the detector has been powered
up for at least one hour to ensure it has sufficiently warmed up.
•
when the room temperature has varied by more than
±3
o
C
(
±
5.4
o
F) from the last cali-
bration.
Proceed as follows:
1. Select the
Examination
tab card.
NOTE
Make sure that no patient is registered before you start the gain
calibration.