• 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)
4Turn selector switch (3) to "
4Press the button "
played.
4The preferred range is set automatically. To change the range
manually press the "
desired range is displayed.
4Open 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
4Turn selector switch (3) to "
4The preferred range is set automatically. To change the range
manually press the "
desired range is displayed.
4Open 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.
22
A".
", and make sure that "0.000" is dis-
" button one or more times, until the
A".
" button one or more times, until the