METRON QA-IDS, User & Service Manual

Page: 29 / 62

5. Control and Calibration
This chapter explains the QA-IDS maintenance procedures, includ-
ing testing and calibration.
5.1 Required Test Equip-
ment
•
Digital multimeter, 10 µ V resolution, 0.1% accuracy.
•
Pressure/vacuum generator, - 400 to + 1700 mmHg pressure.
•
Pressure gauge.
•
Calibrated infusion pump.
5.2 Adjusting the Display
Contrast
1. Remove metal case housing.
1. Set contrast in the display by adjusting potentiometer R160 (lo-
cated at left of CPU) to desired contrast. See Component Loca-
tion Diagram, page A-2.
5.3 Testing Power
Supply to IDS
1. Disconnect cable to the stepper motor, and connect a power
supply with 24 VDC and current limit set to 400 mA.
2. Measure current drawn from the supply voltage, max. 350
mA.
3. Connect mains unit and adjust the voltage to 24V.
4. Switch ON the mains voltage and measure/adjust the fol-
lowing voltages in the sequence given using the multime-
ter. There must be 0 mmHg pressure applied to the
QA-IDS:
Test point Level Max. deviation
V24P (J140/1) 24 VDC ± 1 V
Vcc (C1N12/I) + 5 VDC ± 50 mV
V5N (C1N31/2) - 5 VDC ± 200 mV
Uref 4.096 VDC ± 1 mV
Uad 5 VDC ± 2 mV
29
WARNING!
HIGH VOLTAGES ARE CAPABLE
OF CAUSING DEATH!
USE EXTREME CAUTION WHEN PERFORMING TESTS AND CALI-
BRATION. USE ONLY INSULATED TOOLS WHEN THE UNIT IS
PLUGGED IN, AND THE METAL CASE HOUSING IS OFF.