Omega Engineering CYD201, Operator'S Manual

Page: 41 / 60

OMEGA Model CYD201/CYD208 User’s Manual
Service 5-5
5.7 RECALIBRATION
OMEGA calibrates and certifies thermometers to original factory
specifications for a reasonable fee. You can recalibrate the thermometer to
original specifications, but OMEGA will not warrant these calibrations.
Recalibration requires a digital voltmeter (DVM) with 4½ digit resolution or
better; and 25 k
and 125 k precision resistors with ±0.01% tolerance or
better.
Recalibration involves current source and analog/digital (A/D) converter
calibration. A/D calibration erases all SoftCal™ compensations; perform it
after current source calibration, not before.
5.7.1 Current Source Calibration
1. Allow 30 minute warm-up to achieve rated specifications.
2. Configure 125 k resistor as shown in Figure 5-4. Set Model CYD208 to
channel 1.
3. Connect DVM voltage leads across the resistor and adjust the I ADJ
trimpot (located on rear panel) until DVM displays a voltage of 1.2500
volts ±100 microvolts.
4. Remove DVM and resistor.
Model CYD201 Model CYD208
NOTE: Do not use a voltmeter for A/D Converter Calibration.
Figure 5-4. Calibration Connections