Fresenius Medical Care 2008k Technical Manual page 196

9. With the ground lead of the voltmeter still attached to TP3 (ground) on
the LP450 board (See Figure 7), measure the voltage on the solder side
of pins 1 and 2 of X4 on the LP1026 relay board (See Figure 7). Verify
that both pins are 0 volts.
10. With the syringe, apply a pressure of between at least 30 psi (1550 mmHg)
to the venous line while watching the end of the venous line in the water.
11. Verify that no air escapes from the venous line, indicating that the clamp
is fully occluding the line.
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Figure 7. Level Detector Module.
Fresenius 2008K Preventive Maintenance Procedures
P/N 507297 Rev. A
CHANNEL 1 LED
LIGHTS FIRST
CHANNEL 2 LED
LIGHTS SECOND
TP3 (GROUND)
X4 ON RELAY
BOARD LP1026