Extech Instruments 381676A User Manual page 10

LOGIC TEST
WARNING: To prevent electric shock and damage to the meter or personal injury, do not
measure voltages that may exceed 100V AC rms.
NOTE: If the test leads are disconnected or if the voltage measured is < 1.5V the LED will be green.
1. Use the probe cover if making measurements on category III or above installations
2. Set the function switch to the LOGIC position.
3. Insert the black test lead banana plug into the negative (common) jack at the bottom of
the meter.
4. Connect the black test lead to the circuit's ground (‐) terminal.
5. Hold down the Mode (M) button and touch the test probe to the circuit for
measurement. The LEDs near the tip of the meter will indicate the current logic level.
6. If the measurement is 0~1.5V, the Green LED will light and the display will show a down
arrow, indicating that the logic test result is a LOW ('0') condition.
7. If the measurement is 1.5~3.5V, the Green and Red LEDs will be OFF.
8. If the measurement is 3.5~5V, the Red LED will light and the display will show an up
arrow, indicating that the logic test result is a HIGH ('1') condition. See diagram.
Maintenance
WARNING: To avoid electrical shock, disconnect the test leads from any source of voltage
before removing the back cover or the battery cover.
WARNING: To avoid electrical shock, do not operate the meter until the battery cover is in place
and fastened securely.
This meter was designed to provide years of dependable service. However, if the following
guidelines are not followed, the dependability of the meter can be compromised:
1. KEEP THE METER DRY. If it gets wet, wipe it off and allow it to dry before use.
2. USE AND STORE THE METER IN NORMAL TEMPERATURES. Environmental extremes can
shorten the life of the electronic parts and distort or melt plastic parts.
3. HANDLE THE METER GENTLY AND CAREFULLY.
4. KEEP THE METER CLEAN. Wipe the case occasionally with a damp cloth. Do not use
chemicals, cleaning solvents, abrasives, or detergents.
5. USE ONLY FRESH BATTERIES OF THE RECOMMENDED SIZE/TYPE.
6. IF THE METER IS TO BE STORED FOR A LONG PERIOD REMOVE THE BATTERIES
7. Repairs should only be implemented by trained personnel.
nd Quality Products Online at:
0V 1.5V
LOW '0'
Green LED ON
GlobalTestSupply
www.
3.5V
Green & Red LED OFF
10
5V
HIGH '1'
Red LED ON
381676A-en-GB_V1.1 08/15
.com
sales@GlobalTestSupply.co