Fluke 125 - Reading the Harmonics Screen

Harmonics
Measuring Harmonics
3
3-5
Reading the Harmonics Screen
Depending on the test tool settings the readings show
different measurement units.
Table 3-1 shows the readings for VOLT/AMP/WATT and
CURSOR OFF .
Table 3-2 shows the readings for VOLT/AMP/WATT and
CURSOR ON .
Table 3-1. Harmonics Readings cursor OFF
Mode Main A Secondary A Main B Secondary B
Volt V rms THD Hz
Amp Hz K-Factor A rms THD
Watt W rms THD Hz K-Factor
Table 3-2. Harmonics Readings Cursor ON
Mode Main A Secondary A Main B Secondary B
Volt V Relative value
(%r or %f)
Hz Angle (°)
Amp Hz Angle (°) A Relative value
(%r or %f)
Watt W rms Relative value
(%r or %f)
Hz Angle (°)
Figure 3-3. Reading the Harmonics Screen
THD : total harmonic distortion is the amount of harmonics
in a signal as a percentage of the total rms value (%r) or
as a percentage of the fundamental (%f).
K-factor : indicates the losses in transformers due to
harmonic currents.
Relative value : value of the bar marked by the cursor,
%f as a percentage of the fundamental
VOLT/AMP/WATT value,
%r as a percentage of the total rms VOLT/AMP/WATT
value.
Angle°: the phase angle between the harmonic
component and the fundamental voltage or current.