Voltage Measurements - Extech Instruments EX350 User Manual

Voltage Measurements
CAUTION: When connecting the test leads to the circuit or device under test, connect the
black lead before the red; when removing the test leads, remove the red before the black lead.
For safety, be sure to measure a known voltage before using the instrument on an
unknown circuit
AC Voltage Measurements
1. Insert the black test lead banana plug into the negative (COM) jack and the red test lead
banana plug into the positive (V/Ω) jack.
2. Turn the function switch to the
3. Press the M button to select AC or DC (EX355 only)
4. The meter defaults to the Auto Range mode (Auto displayed on LCD). Press the R button
to access the manual range mode. Press the R button to step through the ranges. Press
and hold the R button to return to the Auto Range mode (Auto will be displayed).
5. Touch the test probe tips to the circuit under test.
6. Read the digital value of the measurement in the display. The display will also indicate
the proper decimal point and measurement type/units symbols.
7. Use the Hz/% button to view the frequency (Hz) or the duty cycle (%) of the measured
voltage
or the m
% Duty Cycle Note: Duty Cycle measurements are
AC only for this meter. Measurement signals must
be 'zero crossing' and must reach ‐0.7V for the
meter to properly display Duty Cycle %.
Fig 4‐1 AC VOLTAGE MEASUREMENTS
10
position.
EX35x‐en‐GB_V1.2 12/15