BEHA-AMPROBE BM357 Инструкция по эксплуатации онлайн [6/24] 529193

CAUTION (Application and removal of the Clamp-on meter)

●For non-invasive ACA current measurements, press the jaw trigger and clamp the

jaws around only one single conductor of a circuit for load current measurement. Make

sure the jaws are completely closed, or else it will introduce measurement errors.

Enclosing more than one conductor of a circuit will result in differential current (like

identifying leakage current) measurement. Locate the conductor(s) at the Jaws center

as much as possible to get the best measuring accuracy. For removal, press the jaw

trigger and remove the jaws from the conductor(s).

●Adjacent current-carrying devices such as transformers, motors and conductor wires

will affect measurement accuracy. Keep the jaws away from them as much as possible

to minimize influence.

THD%-F Total Harmonic Distortion - Fundamental function (model 157 only)

Total Harmonic Distortion - Fundamental (THD%-F) function is designed to give basic

indication on the presence of Harmonics. It is the percentage ratio of the Total

Harmonics RMS value to the Fundamental RMS value of a voltage or current signal,

and is given by the expression:

THD%-F = (Total Harmonics RMS / Fundamental RMS) x 100%

An ideal sinusoidal waveform has a theoretical value of 0 THD%. A badly distorted

sinusoidal waveform may have a much higher THD% value of even up to several

hundreds. It is thus a good parameter to identify the degree of “cleanness” on power

systems.

When the meter is in ACV or ACA function, THD%-F values will be displayed in the

secondary mini display automatically. Press THD%-F button momentarily toggles

THD% readings to main display.