ISA T1000 PLUS User Manual page 109

DOC. MIE91093 Rev. 1.34 Page 109 of 145
reading the number of impulses after the test, N2. The applied
energy is:
Es = (N2 – N1) * Ks.
The energy Et measured by the meter under test is read on
the display. The error of the meter under test is
E% = (Et – Es) * 100 / Es
If the sample meter is not available, the test is performed
as follows.
. Place a suitable sensor in front of the LED (or rotating disk)
of the meter under test, and connect its output to the STOP
input. If the meter outputs a voltage impulse or a relay
contact the sensor is not necessary.
. Define the nominal test energy EN.
. Select the desired test voltage, current and phase angle, V, I
and angle (power factor).
. Define the nominal test time, TN = EN / (V*I*pf): it
should be large enough to avoid that time measurements error
influence the test result (more than 10 s).
. Define the corresponding number of impulses N = EN / Ks.
. Press ON and adjust current, voltage, angle to the desired
values. Press OFF.
. Select on T1000 PLUS the COUNT mode; program a number
of impulses equal to N:
TIMER START/STOP > Stop > Count (N) ESC
. Select the measurement of the generated energy:
METERS > Other internal > Ea – Er ESC
. Press ON+TIME: current and voltage are applied until N+1
complete inputs are detected; at that moment, current
generation ends and the corresponding time is displayed. The
energy applied to the energy meter under test, Es, is read on
the T1000 PLUS display.
The energy measured by the meter under test is computed as
follows: