Hz Push Button: Frequency Measurement - AEMC 721 User Manual

5.5

Hz Push Button: Frequency Measurement

The Hz push button accesses the frequency function while in either cur-
rent or in voltage.
Frequency measurements are possible from 0.5 Hz to 9999 Hz.
Frequency measurements are always Auto Ranging. Pushing the RANGE
push button will only select a fixed range of either 60 or 600 (A or V) on the
bargraph. The RANGE indicator is displayed at the top of the digital display
indicating fixed A or V range selection on
the bargraph. Selection is confirmed with
an audible tone.
To sequence back to Auto Ranging, push
and hold the range selection push-button
for approximately 3 seconds. Displayed
RANGE indicator will disappear, con-
firmed with an audible tone.
PEAK/SMOOTH push-button is active in
Hz but only the Smooth feature is avail-
able. Peak does not exist in Hz mea-
surements (see PEAK/SMOOTH Push
Button, § 5.6). MIN/MAX is active in Hz
(see MIN/MAX Push Button, § 5.7).
If while measuring frequency on a 60 Hz system, the Model 721 indicates
180 Hz, then the third harmonic is dominant and exceeds the fundamental
in magnitude. This may occur in office settings on single-phase loads or
on lighting ballasts. The Model 721 measures the frequency of the signal
with the greatest amplitude.
The analog bargraph will continue to display Arms or Vrms depending
upon which input function is selected.
The HZ function must be exited in order to select another
measurement function. Hz is exited by pressing the Hz push-
button briefly. A brief beep will be emitted.
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