Valhalla Scientific 4300C, Operation Manual

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Routine Maintenance
General
This section provides general maintenance information and a procedure for calibrating the ohmmeter.
The Model 4300C micro-ohmmeter should be calibrated on a routine basis (every 12 months is
recommended) to ensure continued accuracy.
Before performing the calibration procedure below, the ohmmeter should be allowed to warm up at a
stable temperature for at least 30 minutes with the covers in place.
Required Test Equipment
The following equipment is required to perform calibration of the 4300C:
1) Precision resistors within ±0.005%, the following values:
0.1Ω 1Ω 10Ω 100Ω 1kΩ 10kΩ
2) DC voltage standard capable of outputting 10mV, 300mV, 1V and 2V. Valhalla Model 2701C is suitable
for the task.
3) Four wire test lead set.
4) Precision Digital Voltmeter.
Note: If this equipment is not available, the ohmmeter may be returned to Valhalla Scientific for
calibration traceable to NIST.
Pre-Calibration Procedure
The calibration adjustments are accessed by removing the top cover of the instrument.
The locations of the adjustment potentiometers are shown in Figure 12 at the end of this section. Leave
the cover in place as much as possible. After each adjustment is made, the cover should be replaced, and
the instrument allowed to stabilize.
Dangerous AC line voltages exist inside the
instrument. Use caution when adjusting avoid
contact with these voltages.