4. Measuring and testing
4.1 General information
Pushbutton functions:
Switch-on/-off (3), Selftest (3)
Measuring (4.4), Zero balance (4.2)
Preselect test voltage (4.4),
Zero balance (4.2)
The ISO 1Ex has an integrated protective resistor for
current limiting, through this the terminal voltage
during measurements below 100 MΩ can be lower
than the chosen 32, 100, 500 V. The measurement is
not influenced by this.
Note:
The instrument switches off automatically ap-
proximately 60 seconds after the last measurement.
4.2 Zero balance
Perform the zero balance before each serie of
measurement. This is important for the 2 MΩ range
and the functional test.
short-circuit measuring line
switch-on the device with
Hold button
and start the measurement.
Push the button
32 V
100 V
500 V
at the same time and the
zero balance will be performed.
The upper display line indicates “CAL” and the red
LED lights up. Keep both pushbuttons pressed
until the lower display line indicates .000 +/- 5D.
This test has to be repeated with all test voltages
(32, 100, 500 V).
The calibrated value up to max. 1 MΩ remains stored
until a next zero balance is performed. It will not be
reset when the device is switched-off or when the
battery is changed.
23
32 V
100 V
500 V
