Amprobe DMIII-Multitest Power-Quality-Recorder - Manual (Page 101)

AMPROBE
DMIII MULTITEST
EN-99
2. The Voltage anomalies routine "starts" a Voltage anomaly if the RMS value (calculated
over 10ms) is over/under the High/low Threshold and "stops" it when the RMS value
(calculated over 10ms) is under/over the High/low Threshold +/- 3% of Threshold
(where 3% is a fixed percentual of High / Low threshold which introduces an hysterisis
between "Start" and "Stop" voltage values).
Example: Vref =230V +/- 6% -->
High Threshold for start = 243.8, High Threshold for stop: = 243.8 - 7.3 = 236.5V.
Low Threshold for start = 216.2, Low Threshold for stop: = 216.2 + 6.5 = 222.7V.
3. The voltage anomalies routine informs you about:
a. Starting time of the Voltage anomaly
b. Duration
c. Extreme RMS value (calculated over 10ms) during the whole Voltage anomaly.
Example: a voltage anomaly of
Extreme= 246.6V
Duration =20244,09s
means that:
i):
during 20244,09s the RMS voltage value reached 246,6 for 10ms
ii): during 20244,09s the RMS voltage value (calculate over 10ms) was over 236.5V
(High Threshold for stop)
4. Both Voltage anomalies routine and Periods routines have an accuracy of +/- (0.5% rdg
+ 2dgt). As the routines, the calculation, rounding, etc are different in order to compare
the results, You should consider a double global uncertainty. So theoretically a nominal
voltage of 245.2V could become:
a. 246,6V (245.2 + 1.433) measured by Voltage Anomalies routine
b. 243.7V (245.2 - 1.433) measured by Periods Analysis routine.