Copyright 2013 Baker Hughes Company.
146 | DPI
620G Instruction Manual–English
Chapter
12.
Calibration Procedures
12.12.2 Cold Junction (Alternative Method)
Do the procedure as follows:
1. Connect the applicable calibration equipment. Refer to Table
2. Set up the equipment:
•
Function = TC (measure)
•
TC Type = K Type
•
CJ Compensation, Mode = Automatic
3. Set the reference unit temperature: 0°C.
4. Let the equipment get to a stable temperature (minimum: 1
hour since the last power on).
5. Record the values that follow:
•
TC temperature given on the reference unit T (actual).
•
TC temperature given on the calibrator T (measured).
•
CJ temperature given on the calibrator CJ (measured).
6. Calculate the CJ (Cal Value) as follows:
•
CJ (Cal Value) = CJ (measured) - T (actual) + T (measured).
7. Use the calibration menu to do a one-point calibration for the CJ (measure) function.
8. When the display shows “Sampling complete”, set the correct Cal Value = CJ (Cal Value) in
step
6.
9. Check the calibration is correct:
a. Select the TC (measure) function via the Calibrator Task Menu.
b. Check the equipment gives a TC temperature that is the same as the temperature on
the reference unit ±
0.1°C (0.2°F).
12.13 Procedures (CH1): AC mV/Volts (Measure)
Do the procedure as follows:
1. Connect the applicable calibration equipment. Refer to Table
2. Let the equipment get to a stable temperature (minimum: 5
minutes since the last power on).
3. Use the calibration menu (see Section
12.1) to do a two-point AC calibration for the
applicable AC function.
•
Use the local power supply frequency.
•
For the AC mV (measure) function:
point
1 = 200.0
mV
AC
point
2 = 2000.0
mV
AC
•
For the AC Volts (measure) function:
point
1 = 2.000
V
AC
point
2 = 20.000
V
AC
4. Check the calibration is correct:
a. Select the applicable AC mV or AC Volts (measure) function via the Calibrator Task
Menu.
b. Apply the input values that are applicable to the Calibration.
AC mV: 10, 500, 1000, 2000
AC Volts: 5, 10, 20
