Siemens MOBILETT XP - The Exposure Point System; Density and Contrast Adjustment

Siemens AG SPR8-230.840.01.05.02 MOBILETT XP
11.05 CS SD 24
Basic functions 67
Page 67 of 72
Medical Solutions
mAs counter 0
The tube current acquired on board D907 is conducted to a voltage frequency converter
on D916 (CPU).
This converter generates a proportional frequency with a ratio of 100 mA = 16 kHz. The
output impulses can be measured by the oscilloscope at test point F1 on D916. The
impulses are digitally integrated to count the necessary mAs value.
The mAs counter switches the exposure off when the set mAs values are reached and
switches to standby.
If the time limit of 3 or 5 seconds is reached prior to mAs switch-off, the exposure is can-
celed and an error message is output.