HT instruments HT4022 - Manual (Page 47)

HT4020 - HT4022
EN - 14
4.3.7. Measurement of Current Harmonics (HT4022)
CAUTION
Before attempting any measurement disconnect all the test leads from the
circuit under test and from the meter's input terminals.
Fig. 10: Use of instrument for AC harmonic current measurement
1. Select the “ ” position
2. Press the
FUNC/HARM key and keep it pressed at least 1 second until symbol
“THD%” is displayed
3. Open the jaws and clamp only one cable. Pay attention to the alignment marks (see §
4.1.2. and Fig. 10). The instrument displays the Total Harmonic Distortion value of the
input signal. The symbol “THD%” is displayed. See § 8 for the parameter’s definition.
4. With the H
 and H keys you can cycle through all available harmonic values from the
1
st
to the 25
th
order. On the secondary display is shown the order of the harmonic
whose percentage value is displayed on the main one (ex. h3% means third harmonic).
5. Press the FUNC/HARM key to switch to the absolute harmonics’ values displaying
(from 1
st
to 25
th
order). The secondary display indicates the order of the harmonic
whose absolute value is displayed on the main one (ex. h3 means third harmonic)
6. Press FUNC/HARM key to escape this mode going back to current measurement
function (see § 4.3.5)