Calibration - Time Electronics 1018 Technical Manual

6. Calibration

Calibrating the Unit
The unit can be calibrated with a high accuracy DMM with DC voltage, current and
resistance ranges with a specification better than that of the unit's.
Calibration is best carried out on fully charged batteries without the mains supply
connected to ensure that no mains supply interference has any effect on the readings.
It is recommended that a full calibration run is done prior to attempting to adjust any of the
1018's internal calibration adjustment trimmers.
A complete set of results will indicate the calibration status of the unit and determine
whether or not re-adjustment is necessary. If the results are significantly different from
those shown on the sample certificate this may indicate a fault which must be rectified
before re-adjustment is attempted.
Re-adjustment of the 1018's calibration trimmers:
Access to the trimmers requires the top cover of the case to be removed and the rear
panel to be moved away from the rear of the unit. This allows access to the trimmers - see
picture below. Remove the top cover as follows,
Remove the three case fixing screws. These are located in recessed holes in the bottom
of the case. Note that the recessed holes are covered with push fit rubber feet which must
be removed to give access to the fixing screws. Once the screws have been removed
place the 1018 on a flat surface, the top section of the cover can then be eased off and the
rear panel/power supply can be moved back to allow access to the calibration trimmers
which are shown on the diagram below. Please note that the main reference module and
null amplifier module are not shown in this diagram - there are two trimmers on each.
Null Zero Current
Offset Adjust
Null Zero Voltage
Adjust
1V Zero Adjust 1V Full Scale Adjust
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-Deviation Adjust
+Deviation Adjust
10V Full Scale Adjust
100mV & 10mV
Full Scale Adjust
100mA Full Scale Adjust
100V Full Scale Adjust