Performing Measurements - Greenlee 5990A Manuel D'instructions

Performing Measurements

Switching On the Instrument
Auto-Calibration
The instrument is switched ON by pressing the ON/OFF key. After turning on (Fig. 7), the
instrument executes the auto-calibration (Fig. 8).
Note: If batteries are defective or missing and the instrument is powered from mains supply, the
instrument cannot be turned ON.
The test leads have to be disconnected during auto-calibration. If not, the auto-calibration
procedure could fail. After finishing the auto-calibration, the pass icon will appear; the
instrument will go into Insulation Mode (Fig.9) and be ready for normal operation.
Auto-calibration ensures accuracy when measuring very low currents. It compensates for the
effects caused by aging, temperature and humidity changes. Performing a new auto-calibration
is recommended when the temperature changes by more than 10° F (5°C).
Fig. 7 Initial State Fig. 8 Auto-Calibration State Fig. 9 Insulation Measuring Mode
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