Omega 24 - Manual (Page 25)

SERVICE INFORMATION
WARNING
All service information is intended for qualified electronic mainte-
nance personnel only.
1. CALIBRATION PROCEDURES
This is a two-part procedure. Products with thermocouple functions only, follow the
Thermocouple Calibration procedure below. Products with resistance functions (RTD,
thermistor, ohms) follow first the Thermocouple Calibration procedure, then the Resistance
Calibration procedure.
A. THERMOCOUPLE CALIBRATION
Test Equipment Required:
1. Thermocouple simulator (OMEGA CL521, or equivalent) calibrated to ITS-90.
2. Microvolt DMM (OMEGA OM7551, or equivalent)
3. Calibration cables, per Figures 11, 12, 13.
NOTE: The copper constantan cables used in Figures 12 and 13
need to be calibrated. Voltage errors in these cables should be com-
pensated at the simulator.
4. Calibration cover (OMEGA 820-307-4).
Ambient Conditions:
Units should be calibrated at an ambient temperature of 23°C ±1°C, with relative humidity less
than 80%.
Preparation for Calibration:
1. Remove battery from unit under test (U.U.T.). Refer to Battery
Installation/Replacement section in the manual.
2. Remove bottom-cover from U.U.T. Refer to Disassembly Instructions.
3. Remove calibration-jumpers J1 and J2 from printed-circuit board.
NOTE: Removal of J1, J2 causes partial loss of previously stored
calibration data. Do not remove these jumpers unless recalibration
is intended.
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