Newtons4th PSM1700 User Manual

PSM1700 PsimetriQ user manual
15-1
15 Harmonic analyser
The PsimetriQ harmonic analyser computes multiple DFTs
on the input waveforms in real time (refer to the chapter
on frequency response analysis for the formulae for DFT
analysis).
There are three modes of operation: single harmonic,
difference thd, and series thd. In single harmonic mode,
the specified harmonic is displayed both in Volts and as a
ratio to the fundamental; in either thd mode, the
computed thd and a specified harmonic are displayed as a
ratio to the fundamental.
In difference thd mode, the thd is computed from the rms
and fundamental:
thd = 1/h
1
√ ( rms
² - h
1
²)
In series thd mode, the thd is computed from a series of
up to 64 harmonics.
i = n
thd = 1/h
1
√
 h
i
² where h
i
is the i
th
harmonic
i = 2
In series mode the magnitude and phase of all the
harmonics can be seen as a table or the magnitudes can
be displayed as a bargraph which changes in real time with
the measurements. When viewing the bargraph, ZOOM+
and ZOOM- change the vertical axis by a factor of 10.
In all cases the harmonics are phase referred to CH1
fundamental so that their in-phase and quadrature
components may be separately filtered to minimise noise.

Newtons4th PSM1700 Specifications

General

Brand	Newtons4th
Model	PSM1700
Category	Measuring Instruments
Language	English