LEM MachineTest 204 Manuel D'utilisation page 16

MEASUREMENTS
In case of measurement of DC voltage, only one measurement is enough to be carried
out (as the result is repeatable).
U
Fig. 12. Graphic presentation of U
machine (DC voltage)
In order to avoid inconvenient repeating of the measurement in some cases even when
measuring AC voltage, the Residual Voltage Tester offers two modes of measurement
namely:
a) Linear mode
This mode shall be used when dealing with known objects which comprise only
"linear" internal components (R,L,C). In such case simple exponential voltage
decreasing is present after switching off tested object. Such a diagram is then
mathematically scaled to maximal value of mains voltage and thus the
measurement is not required to be repeated, see the figure below.
u
Fig. 13. Diagram of voltage decreasing in case "linear" components only
are involved
switch off always at the same DC voltage
1s / 5s
in case of measurement inside tested
RES
diagram is automatically
scaled to max. value of
mains voltage
15
U
RES
t
t