Operation; Using The Frequency Selector Switch; Ac Current Measurements - Extech Instruments 380943 User Manual

Operation

Using the Frequency Selector Switch

50/60Hz position (low pass filter)
Use the 50/60Hz position when measuring circuits with a frequency bandwidth of 50/60Hz.
Since the meter has superior frequency response, measurement results may include
higher frequencies and harmonics of the fundamental frequency. Putting this switch in the
50/60 position activates the meter's low pass filter minimizing the affects of high frequency
noise. The filter's cut-off frequency is 100Hz with 24dB/octave attenuation (approx.).
WIDE Position (for high frequencies)
Put the slide switch in the WIDE position if the circuit under test is a high frequency
generating device (up to 1KHz) such as an inverter, switching regulator, etc. To verify the
presence of a high frequency signal, take measurements in both switch positions. If the
readings are widely different, then a high frequency signal can be assumed present.

AC Current Measurements

Basic Current Measurement Procedure
WARNING: To avoid electric shock, disconnect the test leads from the meter before
making current measurements.
1. Set the Function switch to the desired current range.
2. Set the Frequency slide switch to the appropriate position (refer to the paragraph
above to determine which position to use).
3. Press the jaw trigger to open the clamp jaws and clamp around the conductor(s)
ensuring they're fully enclosed by the clamp jaws.
4. Refer to the applications diagrams below for specific measurement configurations.
5. Read the ACA value on the LCD digits and the bargraph.
AC Current Applications
Load Current Measurments
4 Model 380943 Ver. 2.1 11/2002