Frequency (1-Cycle Update); Demand Measurements (1-Second Update) - Novatech Bitronics M87X Series Manual

4.6 Frequency (1-Cycle Update)

Frequency is calculated every cycle for every input but the Auxiliary Voltages. The M87x
monitors the change in Phase Angle per unit time using the Phase Angle measurement for
the fundamental generated by the FFT. The System Frequency is the frequency of the
input used for synchronizing the sampling rate (Section 3.2.2).
Figure 7 - Sign Conventions for Power Measurements

4.7 Demand Measurements (1-Second Update)

The traditional thermal demand meter displays a value that represents the logarithmic
response of a heating element in the instrument driven by the applied signal. The most
positive value since the last instrument reset is known as the maximum demand (or peak
demand) and the lowest value since the last instrument reset is known as the minimum
demand. Since thermal demand is a heating and cooling phenomenon, the demand value
has a response time T, defined as the time for the demand function to change 90% of the
difference between the applied signal and the initial demand value. For utility applications,
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ML0021 August 15, 2018 Copyright 2018 Bitronics, LLC