22
• Before carrying out measurements, verify that the instrument is
functioning properly, for example by testing on a known voltage
or current.
• Make sure that the test leads are undamaged.
4.2 Current Measurements
Never measure currents in uninsulated conductors carrying
more than 250 V !
Only handle test leads and probes on the grips provided.
Avoid touching the probes under any circumstances.
4.2.1 DC current measurements (
only
UNITEST Clamp Meter
CHB 37)
4
Turn selector switch (3) to “
A
“.
4
Press the button “ “, and make sure that “0.000“ is dis-
played.
4
The preferred range is set automatically. To change the range
manually press the “ “ button one or more times, until the
desired range is displayed.
4
Open the clamp, and close it round the conductor. Make sure
that the clamp properly encircles the conductor, and that there
is no air gap between the jaws.
For a positive reading, the current must be flowing in the
direction of the arrow on the clamp.
If the display is not visible during measurement, press the
“ “ button (2) to retain the display. The clamp can then be
removed from the conductor and the stored value read.
4.2.2 AC current measurements
4
Turn selector switch (3) to “
A
“.
4
The preferred range is set automatically. To change the range
manually press the “ “ button one or more times, until the
desired range is displayed.
4
Open the clamp, and close it round the conductor. Make sure
that the clamp properly encircles the conductor, and that there
is no air gap between the jaws.
If the display is not visible during measurement, press the
“ “ button (2) to retain the display. The clamp can then be
removed from the conductor and the stored value read.
PTDB93470-05.qxd 14.12.2005 9:56 Uhr Seite 22
