Beha-Amprobe MT204-S Manual Del Usuario página 29

Residual voltage measurement
In non-linear mode it is assumed there are also
components involved in discharge process (relays, gas lamps etc.) and
therefore discharge characteristic is non-exponential or even unpredictable,
see the diagram below.
Figure 14: Discharge diagram in non-linear circumstances
In this case result can not be scaled to peak value, so actual value after the
end of measuring time is registered and evaluated.
In this operation mode the measurement must be repeated several times to
ensure the unit under test was tested under varying shut-off conditions. The
highest measured value must be recorded.
Trigger conditions
The instrument recognizes disconnection of mains voltage when one of the
following two conditions occurs:
-
AC or DC input voltage:
If mean value of input voltage drops down with a slope of at least
25 V / s (mean value measured each period)
-
AC input voltage only:
If momentary voltage differs from ideal sine waveform value more
than 40 % of peak value of previous half period (momentary voltage
sampled 100 times per period)
• If in linear mode the mains voltage is disconnected at too low value
(<20% of peak value), it means scaling of measurement result to peak
value is not possible. In this case "REPEAT THE MEASUREMENT" message
appears on the display and the measurement must be repeated.
Non-linear mode
"
"non-linear"
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"
or unknown