Special Tools; System Calibration - GE Giraffe Service Manual

3.2 Special Tools

The following tools (or their functional equivalents) are required to complete the recommended service
procedures:
• Digital Multimeter, 4-1/2 digit
• PLCC Extractor for removing socketed chips
• Leakage Current Tester
• Static Control Work Station (recommended)
• Light gray touch-up paint (Munsell .16GY8.56-0.44 chroma)-18ml .......................................... 6600-0714-200
• Servo Humidity Calibration Kit .................................................................................................................... 6600-0048-850
• 5 kilogram (5000 gram) Class F test weight* ........................................................................................ 6600-0209-800
*The scale can be calibrated using a Class F calibration weight between 1 kilogram and 8 kilograms (accuracy
of 0.01%).
NOTE: Do not use simulator 6600-0876-700 for validation testing.

3.3 System Calibration

NOTE: If Only performing line voltage calibration, follow instructions in next section, 3.4.
IMPORTANT: Be sure to perform System Calibration after replacing a control board.
1. Turn power off.
2. Remove electrical enclosure back panel.
3. Unplug the temperature sensors from J1, J4 and J2 on the control board.
4. Move jumper JP1 to the CAL MODE position on the control board. (Refer to "Figure 3-1 Control Board Test
Points" on page 20.) Be sure to orient the jumper correctly so pins 5-6 and 7-8 are shorted.
5. Turn power on. After running the power-up testing INITIALIZING will be displayed and dots will move across
the top of the screen.
6. After about 90 seconds CALIBRATION MODE, Enter "VREF", and Enter "Mains" will be displayed.
7. Using a 4 ½ digit DVM (capable of measuring to 0.1 millivolt) measure VREF at TP1, pins 1 and 6 (pin 6 is
ground) on the control board. Measure to the nearest 0.1 millivolt. (Typical voltage reading will be 1.2350)
8. Dial in VREF using the control knob. Press the knob to enter the value.
9. Measure the Mains Voltage at the AC connectors at the bottom of the electronics enclosure cover.
© 2001 by Datex-Ohmeda, Inc.. All rights reserved.
Chapter 3: Calibration and Maintenance
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