Gossen MetraWatt METRISO 1000 IR, Руководство по эксплуатации, Страница: 14 / 28

14 GOSSEN-METRAWATT
7.2 ISO-
Ω
measurement up to 3 G
Ω
with manual range selection
í
Set the rotary switch (6) to one of the three „ISO-
Ω
“ posi-
tions. Depending upon the nominal voltage of the device
under test, you can measure the insulation resistance
with a nominal voltage of 250 V, 500 V or 1000 V.
í
Check that the device under test is free from external
voltages as described for the measurement with auto-
ranging in section 7.1.
í
Briefly press one of the two pushbuttons „RANGE
↑
“ (3)
and „RANGE
↓
“ (4).
You thus leave autoranging and fix the 3 M
Ω
measuring
range. The tester always selects this output range when
you set the rotary switch (6) to one of the three „ISO-
Ω
“
positions. The LCD shows the word „ RANGE “ in place of
„AUTO“.
í
You now can select the measuring ranges manually with
the two pushbuttons (3) and (4). Each time you press the
pushbutton „RANGE
↑
“ (3) you switch to the next higher
measuring range, each time you press the pushbutton
„RANGE
↓
“ (4) you switch to the next lower range.
You can recognize the measuring range selected on the
LCD by the numerals immediately under the decimal
points and by the unit.
í
Apply the two probes to the measuring points.
í
Press the measurement pushbutton (8) in the probe (9)
and hold it at this position. The measured value is dis-
played in digital and analog form on the selected meas-
uring range, regardless of its magnitude. Now the analog
scale is linear.
Depending upon the measured value and the selected
measuring range, it is possible that measured values are
not displayed with optimum resolution or with overrange
display („OL“ and/or triangle at the end of the analog
scale).
í
Now release the measurement pushbutton (8) in the
probe.
The measured value is held same as described in
section 7.1 for the measurement with autoranging.
As the measurement of the insulation resistance is
always made with maximum resolution, you now can
select the range which displays the measured value with
optimum resolution, using the pushbuttons „RANGE
↑
“
(3) and „RANGE
↓
“ (4).