YOKOGAWA TA220 User Manual page 154

Explanation
IM 704610-01E
12.5 Calibration (Changing the Factory Default Calibration Values)
The calibration function can be used to change the factory default calibration values of
the TA220. However, once you make the changes, you cannot restore the calibration
values back to their factory defaults. Perform calibration when the allowable range is
exceeded in the performance test described in section 12.6 or when parts of the TA220
are replaced. If a problem is discovered during calibration, contact the dealer from which
you purchased the instrument for repairs.
Removing Signal Cables
When performing the self test, remove all cables connected to the instrument (both input
and output) other than the power cable and communication cable.
If the TA220 is in remote mode at this point, calibration cannot be performed. Switch
from remote mode to local mode.
Warm Up
Warm up the TA220 for at least thirty minutes with the power turned ON before
performing calibration. During warm-up or calibration, make sure not to block the inlet
and exhaust holes on the top, bottom, and rear panel of the instrument.
Calibrated Items
The following items can be calibrated:
• DC voltage level.
• Time-voltage conversion
• Measurement/computation
Changing the Factory Default Calibration Values
• When calibration completes normally, new calibration values are obtained. To apply
the new calibration values, you must change the factory default calibration values. If
you change the factory default calibration values, you cannot undo the changes.
Please confirm that it is okay to change the factory default calibration values
beforehand. However, once you make the changes, you cannot restore the default
calibration values even if you initialize them (see section 11.2).
• If the factory default calibration values are not changed, the new calibration values are
not applied.
• The factory default calibration values can be changed only when all calibrations are
completed normally.
• If you do not change the factory default calibration values, return the instrument to the
condition in which TESTMODE is displayed in Display 2, or turn OFF the power
switch.
Checking the Calibration Result
If PASS is displayed after calibration, the result is normal. If a problem is detected, a
hexadecimal value indicating the problem can be displayed separately for each
calibration item. When contacting your nearest YOKOGAWA dealer for repairs, please
give them that hexadecimal number.
Restarting the Instrument
After calibration, check that the TA220 starts up normally and that it is ready to make
measurements.
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