MD 9273 Leakage Clamp
Description of Test Functions
15
3.3
Test functions
Measuring mA, A and V
The following sections describe the functions available in the current and voltage measurement modes
(positions of the rotary switch in mA, A and V). To select the desired function, the
F
key shall be pressed
repeatedly until it is selected. For current measurements (mA, A), it is recommended to disconnect the test
leads, except for the Inrush function where voltage can be measured
(see “Warning” section).
TRMS value measurement function
TRMS is the effective value of the current or the voltage. Secondary reading on the display is the THD (total
harmonic distortion ratio) or the frequency of measured signal. THD is the ratio between the higher frequency
components of the signal with the essential component (at 50 Hz or 60 Hz), expressed as percentage. A high
THD value indicates high distortion of the measured signal whilst a 0%THD indicates a pure single-frequency
sinusoid. Data hold in this mode is possible as well as the register of maximum and minimum values using
the
H
key.
Frequency measurement
In this function, the frequency of the measured signal is displayed. Press
F
button for more than 2 s while in
the TRMS measurement function to enter frequency measurement mode. To return to THD, press the same
button again for more than 2 s.
