Operation - Extech Instruments 380320 User Manual

Operation

CAUTIONS
Observe all safety precautions when the FUNCTION switch is set to the 250V, 500V or 1000V
positions.
Connect the meter test leads to the circuit under test before operating the TEST key.
Do not touch the clip ends of the test leads when the TEST key is pressed.
Some electrical equipment, especially cables, may retain an electrical charge when
disconnected from the line. It is good practice to discharge such equipment with grounding
straps, or other suitable devices, before touching or making connections. The meter
automatically discharges the test circuits when the spring loaded TEST key is released.
IMPORTANT NOTE
Remove all power to the circuit under test when making resistance measurements. If any
voltage is present in the test circuit the red on the meter scale plate will light. Immediately
disconnect test leads and turn off power to test circuit.
Live Circuit Indicator LED
If the Live Indicator status LED is lit, voltage is present on the device under test. DO NOT proceed
to test with voltage present. Shock to the user and damage to the meter or device under test can
result if testing is done with voltage present. Proceed with testing only when the voltage is removed
from the device under test.
Connecting Test Leads
For all measurements, connect the red test lead to the V input terminal and the black test lead to
the COM input terminal.
Battery Check
1. Set the range selector switch to the BATT.CHECK position
2. Press and hold the TEST key.
3. Press the Batt Check key.
4. Observe the meter pointer. If the pointer falls in the BATT GOOD range of the bottom scale,
batteries are good. If the pointer falls outside of (to the left of) the BATT GOOD area, replace
the batteries.
Test Lead Check
1. Set the FUNCTION switch to the 3range.
2. Touch the test lead tips together and press the TEST key.
3. Resistance should read less than 0.5.
4. With the leads not touching, the display should read infinity.
5. Readings displayed other than the readings described above are indicative of a test lead
problem. The test leads must be replaced before using the meter. Failure to do so could result
in damage to equipment and electrical shock.
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