Keysight Technologies Digital multimeter, U1270-series, 30000 counts, CAT III 1000 V, CAT IV 600 V U1273A Ficha De Dados
Códigos do produto
U1273A
2
Key Functions
Low Impedance (Z
LOW
)
The U1272A and U1273A are dual
input impedance digital multimeters.
The DMM’s high input impedance
is preferred in most electrical
measurements because it would not
load the circuit under test. However,
to obtain accurate measurements
on circuits that may contain stray
voltages, the U1272A and U1273A’s
2 kΩ low impedance function comes
in handy. Stray voltages are usually
found in non-energized electrical
wiring adjacent to powered wires due
to capacitive or inductive coupling
between these wires. When a pair
of test leads is placed between the
open circuit and neutral conductor,
the circuit is then complete and forms
a voltage divider in conjunction with
the input impedance of the multimeter.
High input impedance multimeter is
sensitive enough to measure volt-
age coupled into the disconnected
conductor, thus giving an inaccurate
indication of a live conductor. The low
impedance function serves to elimi-
nate false readings by dissipating the
stray voltages, thus improves safety
and measurement efficiency during
voltage.
Figure 1. U1272A helps you identify the presence of stray voltage on a disconnected wire running parallel with the wire
powering up the VFD to an industrial motor. The image on the right shows the U1272A in low impedance mode.