Specifications

Low impedance mode (Z
LOW
)
Electrical conduit is commonly found in
buildings, from manufacturing plants to
residential homes. It provides enclosed
conductors protection from moisture,
chemical vapors and impact. The use
of electrical conduit simplifi es wiring
changes as existing conductors can be
withdrawn and new conductors installed
with little disruption along the path of the
conduit.
Although convenient and safe, unused
wires can sometimes run parallel with
energized wiring. This may induce
capacitive coupling between these wires,
causing an undesirable transfer of energy
from the energized wiring to the unused
wiring. This complicates installation or
maintenance of electrical wiring as volt-
age may be detected on the unused wir-
ing. This is known as ‘stray voltage’. This
causes complications for technicians, who
would have to spend time troubleshooting
or isolating wires in order to determine
the source of the voltage.
Smart Ω
In integrated circuit (IC) manufacturing
plants, ground continuity measurements
on workstations are important to ensure
that electrostatic discharge (ESD) is mini-
mized. As electronic components become
further miniaturized, these components
are more sensitive to ESD. In order to
maintain a workstation, the common
ground point for continuity to earth or
electrical ground should be checked
periodically.
During this continuity check, leakage
current may be found fl owing through
the common ground conductor to earth
ground. This leakage current causes
inaccurate ground continuity measurement.
The Agilent U1272A/U1273A handheld
digital multimeters (DMM) allow you to
read the leakage current with its Smart
Ω function. With the U1272A/U1273A's
dual display and 30 Ohms range, you can
obtain accurate resistance measurement
and read leakage current simultaneously.
Multimeters with a low impedance mode
are able to identify the presence of stray
voltages in non-energized wiring. The
low impedance mode eliminates false
readings by providing a load to the circuit
during voltage testing.
The Agilent U1272A/U1273A are dual
impedance digital multimeters, offering
both high and low impedance modes. The
DMM’s high impedance function can be
used in most electrical measurements in
the industrial environment because it will
not load the circuit under test. Switching
to the low impedance mode allows the
U1272A/U1273A to perform accurate
measurements on circuits that may con-
tain stray voltages. This eliminates the
need of an additional low impedance
multimeter, such as a solenoid tester. If
this mode is used when real voltage is
present, the Agilent U1272A/U1273A has
a built-in positive temperature coeffi cient
(PTC) thermistor as an overcurrent protec-
tion element.
Specifi cations of the U1270 Series Digital Multimeters
Di U1271A U1272A U1273A U1273AX
Basic features
Display resolution 30,000 30,000 30,000 30,000
Display type LCD LCD OLED OLED
Auto/manual ranging Yes Yes Yes Yes
Analog bar graph Yes Yes Yes Yes
Backlight Yes Yes Yes Yes
AC bandwidth 20 kHz 100 kHz 100 kHz 100 kHz
True RMS AC AC + DC AC + DC AC + DC
Measurements
Voltage DC
Range
Accuracy
300 mV to 1000 V
0.05% + 2 cnts
30 mV to 1000 V
0.05% + 2 cnts
30 mV to 1000 V
0.05% + 2 cnts
30 mV to 1000 V
0.05% + 2 cnts
Voltage AC
Range
Accuracy
Bandwidth
300 mV to 1000 V
0.7% + 20 cnts
45 Hz to 20 kHz
30 mV to 1000 V
0.6% + 20 cnts
45 Hz to 100 kHz
30 mV to 1000 V
0.6% + 20 cnts
45 Hz to 100 kHz
30 mV to 1000 V
0.6% + 20 cnts
45 Hz to 100 kHz
Current DC
Range
Accuracy
300 µA to 10 A
0.2% + 5 cnts
300 µA to 10 A
0.2% + 5 cnts
300 µA to 10 A
0.2% + 5 cnts
300 µA to 10 A
0.2% + 5 cnts
Current AC
Range
Accuracy
Bandwidth
300 µA to 10 A
0.9% + 25 cnts
45 Hz to 2 kHz
300 µA to 10 A
0.6% + 25 cnts
45 Hz to 2 kHz
300 µA to 10 A
0.6% + 25 cnts
45 Hz to 2 kHz
300 µA to 10 A
0.6% + 25 cnts
45 Hz to 2 kHz
Resistance
Range
Accuracy
300 Ω to 100 MΩ
0.2 % + 5 cnts
30 Ω to 300 MΩ
0.2% + 5 cnts
30 Ω to 300 MΩ
0.2% + 5 cnts
30 Ω to 300 MΩ
0.2% + 5 cnts
Frequency
Range
Accuracy
99.999 Hz to 999.99 kHz
0.005% + 5 cnts
99.999 Hz to 999.99 kHz
0.005% + 5 cnts
99.999 Hz to 999.99 kHz
0.005% + 5 cnts
99.999 Hz to 999.99 kHz
0.005% + 5 cnts
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