Detector; Pmt Strips; Power Strip - Philips CARDIOMD Service Manual

Test Terminals
5.4.2

Detector

24
18
12
6
OUT
Figure 5.9 Location of detector test points
5.4.2.1

PMT Strips

All measurements are referenced to GND, which is represented by any of the mounting screws.
Vtune
WP
OUT
Figure 5.10 Typical PMT output
5.4.2.2

POWER Strip

All measurements are referenced to local GND pins on the power strip.
5-16 CardioMD Service Manual
23 22
17
16
11 10
5 4
OUT OUT
is a DC test point that reflects the tune value for the particular PMT.
Range: 0 – 5 V = digital tune value 0 – 1023.
is a DC test point that reflects that the autotune loop on the particular PMT is
operational. At normal operation, the voltage reading should be 2 – 4 V. If the
voltage reading is lower or negative, then the inherent PMT gain is too low. In
that case, either the high voltage is too low or the PMT is defective
is an oscilloscope test point showing the output from the PMT preamplifier. The
magnitude of scintillation signals from technetium or cobalt should be around
4 – 5 Vpp. Base line should be 0 V ± 30 mV.
21 20
15 14
9 8
3 2
OUT OUT
19
13
7
1
OUT
1MAN0158-H11 04-2005 CSIP Level 1