To exit manual mode, press the RANGE button until a second beep is heard (the meter returns
to auto mode).
On Frequency mode, the PEAK/SMOOTH button switches between SMOOTH mode (a
running average of readings over a 3 second interval), and the normal mode of frequency
measurement.
In RECORD mode and on HOLD, the Hz button is disabled.
To exit the Frequency function, press the Hz button until a beep is heard (return to Amps
mode).
Method of data acquisition of frequency values:
On auto:
0.5 Hz
Meter measurement
On manual:
0.5 Hz
On manual (measurement by counter):
The frequency measurement rule applied to the 0.5 Hz - 10 kHz range is established as
follows:
The Hz count (N) is carried out over 150 to 250 ms approx.
A counter (T) fixing a time reference is now engaged, and carries out the time count
previously defined.
Next is the calculation: N/T = F (F being the frequency of the signal).
On manual the transition from the beginning of the cycle activates the time reference and
holds this duration as a fixed unit after 150 to 250 ms according to the resolution.
On AUTO mode:
- For frequencies of less than 5 Hz or more than 2 kHz, the frequency measurement is
identical to that of the manual range.
- Between 5 Hz and 2 kHz, to set and hold the measurement count N, the following
condition is required: during a transition N, the value of the current is analysed. So a
current value which must be at least equal to a precalculated threshold sets off the
process of setting the counter (T) and locks it after approx. 250 ms.
In conclusion, on AUTO or manual mode, all current measurements can be made between
0.5 Hz and 10 kHz. Nevertheless, it is only possible to measure the frequency of distorted
signals in the measurement range 5 Hz-2 kHz (for example, machines with a rotary action:
variable frequency motors, ...) in auto mode.
5 Hz
Measurement synchronised with the current
Meter measurement
2 kHz
Meter measurement
39
10 kHz
10 kHz