Keysight U1281A User manual

Keysight U1281A/
U1282A Handheld
Digital Multimeter
Quick Start Guide

2 Keysight U1281A/U1282A Quick Start Guide
Safety Notices
CAUTION
A CAUTION notice denotes a
hazard. It calls attention to an
operating procedure, practice, or
the like that, if not correctly
performed or adhered to, could
result in damage to the product
or loss of important data. Do not
proceed beyond a CAUTION
notice until the indicated
conditions are fully understood
and met.
WARNING
A WARNING notice denotes a
hazard. It calls attention to an
operating procedure, practice, or
the like that, if not correctly
performed or adhered to, could
result in personal injury or
death. Do not proceed beyond a
WARNING notice until the
indicated conditions are fully
understood and met.
EMC Information
The U1281A/U1282A is
EMC-certified in compliance with
IEC 61326-1/EN 61326-1, ICES/
NMB-001, and AS/NZS CISPR 11.
Safety Information
The U1281A/U1282A is
safety-certified in compliance with
IEC/EN 61010-1, IEC/EN
61010-2-033, CAN/CSA-C22.2 No.
61010-1-12, CAN/CSA-C22.2 No.
61010-033-12, ANSI/UL
61010-1-12, and ANSI/UL
61010-033-12. Use with standard
or compatible test probes.
Safety symbols
Direct current (DC)
Alternating current (AC)
Caution, risk of
electric shock
Caution, risk of danger
(refer to this manual for
specific Warning or
Caution information)
Earth (ground) terminal
Equipment protected
throughout by double
insulation or reinforced
insulation
Category III 1000 V
overvoltage protection
Category IV 600 V
overvoltage protection
CAT III
1000 V
CAT IV
600 V
2 Keysight U1281A/U1282A Quick Start Guide
For further safety information details, refer to the
Keysight U1281A/U1282A Handheld Digital Multimeter
User’s Guide.

Keysight U1281A/U1282A Quick Start Guide 3
Keysight U1281A/U1282A Quick Start Guide 3
Standard Shipped Items
Verify that you have received the following items
with the shipment of your U1281A/U1282A
multimeters:
✔Test leads (red and black)
✔IR-to-USB cable
✔Four 1.5 V AA batteries
✔Printed copy of the U1281A/U1282A
Quick Start Guide (this document)
✔Printed copy of the Certificate of Calibration
If any item is missing or damaged, keep the
shipping materials and contact the nearest Keysight
Sales Office.
NOTE
– The descriptions and instructions in this guide
apply to the U1281A and U1282A Handheld
Digital Multimeters.
– The model U1282A appears in all illustrations.
– All related documents and software are
available for download at
www.keysight.com/find/hhTechLib.
NOTE
Your multimeter is capable of receiving remote
commands and performing remote data logging. To
use these features, you will need either an
IR-to-USB cable (included in the shipment) or an
IR-to-Bluetooth®adapter (U1117A, purchased
separately), and the Keysight Handheld Meter
Logger Software (downloadable from
www.keysight.com/find/hhmeterlogger).
For more information on the remote commands,
refer to the U1281A/U1282A Programming Guide.

4 Keysight U1281A/U1282A Quick Start Guide
4 Keysight U1281A/U1282A Quick Start Guide
Install or Change the Batteries
The multimeter is powered by four 1.5 V AA
batteries (included in the shipment).
Before installing or changing the batteries, pull from
a corner and stretch the orange rubber holster to
remove it.
Turn On the Multimeter
Turn the rotary switch from the position to any
other position to begin making measurements.
A
mACOM
V
V
A
V
mV
mV
U1282A
True
RMSMul
ti
meter
mA
PeakV
sense
Dual
Auto
FUSED
440mACATI
II
1000V
600V
CAT
IV
MAX
10AMAX
FUSED
OUT
OUT
MHz
RMT
U1282A
True
RMSMul
ti
meter
U1282A
Tr
ue
RMSMul
time
te
r
Vsense
Peak
Vs
ense
Dual
Auto
V
mV
OUT
MHz
mA
A
V
mV
A
COM
V
FUSED
440mACATII
I1000V
600V
CA
TI
V
MAX
10A
MAX
FUSED
OUT
R
MT
A
mACOM
V
V
A
V
mV
mV
T
rue
RMS
Mul
timeter
mA
PeakVsense
Dual
Auto
FUSED
440mACAT
I
II
1000V
600V
CATIV
MAX
10AMAX
FUSED
OUT
OUT
MHz
RM
T
T
rue
RMS
Mul
timete
1 2
6
3
4 5
7 8
V
A
V
mV
mV
mA
OUT
MHz

Keysight U1281A/U1282A Quick Start Guide 5
Keysight U1281A/U1282A Quick Start Guide 5
The Multimeter at a Glance
A
mA COM
V
V
A
V
mV
mV
U1282A True RMS Multimeter
mA
Vsense
Peak Vsense
Dual
Auto
FUSED
440mA CAT III 1000V
600VCAT IV
MAX
10A MAX
FUSED
OUT
OUT
MHz
RMT
Vsense red LED indicator
Display screen
Keypad
Rotary switch
Input terminals
IR communication port
Test lead/probe holders
Battery access
(under the orange rubber holster)
Tilt stand
Fuse access
(under the orange rubber holster)

6 Keysight U1281A/U1282A Quick Start Guide
6 Keysight U1281A/U1282A Quick Start Guide
Using the Rotary Switch
Legend Measurement function
Model
U1281A U1282A
AC V/AC V with Low Pass Filter (LPF)[a] ✔✔
AC mV/AC mV with LPF[a] ✔✔
DC/AC/AC+DC V ✔✔
DC/AC/AC+DC mV ✔✔
Resistance/Continuity ✔✔
Diode/Frequency counter[a] ✔✔
Capacitance/Temperature ✔✔
DC μA/mA/AC μA/mA/AC+DC μA/mA ✔✔
DC A/AC A/AC+DC A ✔✔
Square wave mode[a] —✔
[a] For U1282A only.
V
mV
V
mV
MHz
mA
A
OUT
WARNING
Remove the test leads from the measuring source
or target before changing the rotary switch
position.
Refer to the U1281A/U1282A User’s Guide for a
complete list and description of all rotary switch
labels.

Keysight U1281A/U1282A Quick Start Guide 7
Keysight U1281A/U1282A Quick Start Guide 7
Using the Keypad
Legend Key response when pressed for:
Less than 1 second More than 1 second
– Starts the Max/Min/Avg
recording
– Switches between the
Max/Min/Avg recording
modes
– Stops the Max/Min/Avg
recording
– Starts and stops the
Peak recording
Sets the Null/Relative mode
Enables and disables the
non-contact voltage
detection – Vsense[a]
Sets a manual range Enables autoranging
Enables the frequency test
mode for current or voltage
measurements
Starts and stops data
logging
Turns the backlight on/off
Activates and deactivates
the dual display mode (if
supported by the
measurement)
Switches between the
regular and shifted (icons
printed in orange) functions
Enters the Log Review
menu
– Freezes the present
reading in the display
(TrigHold mode)
– Automatically freezes the
present reading when
certain conditions are met
(AutoHold mode; when
enabled from the
multimeter’s Setup mode)
– Exits the AutoHold mode
– Stores a record of the
measured signal and
exports it via the
multimeter’s optical
communication port
Exits the TrigHold mode
[a] For the U1282A only
MaxMin
Vsense
Range
Hz
Save
Esc
Shift
Hold

8 Keysight U1281A/U1282A Quick Start Guide
8 Keysight U1281A/U1282A Quick Start Guide
Using the Input Terminals
WARNING
To avoid damaging this device, do not exceed the
input limit.
Rotary
position Input terminals Overload protection
1000 Vrms
1000 Vrms for short
circuit <0.3 A
440 mA/1000 V,
fast-acting fuse
11 A/1000 V,
fast-acting fuse
This input terminal is for use with the Remote Switch Probe (purchased
separately). The button on the probe emulates the button on the
multimeter by default.
V
V
COM
mV
V
mV
MHz
mA
mA
COM
A
A
COM
OUT
RMT
Hold

Keysight U1281A/U1282A Quick Start Guide 9
Keysight U1281A/U1282A Quick Start Guide 9
Safety Alerts and Warnings
Hazardous voltage indication
The multimeter will display the hazardous voltage
( ) symbol as an early precaution when the
measured voltage is:
This symbol will also be displayed when the input
signal exceeds the limitation of measuring circuit as
frequency dependence.
Hazardous current indication
The multimeter will display the hazardous current
( ) symbol as an early precaution when the
measured current has reached the maximum fuse
rating as follows:
Measurement DC AC
V (mV) ≥+30 V or +OL ≤–30 V or –OL ≥30 V or OL
Measurement DC AC
A≥+11 A or +OL ≤–11 A or –OL ≥11 A or OL
μA/mA ≥440 mA or +OL ≤–440 mA or –OL ≥440 mA or OL
CAUTION
If your measuring current is > 10 A ~ 19.999 A, you
will need to lower the current within a 30-second
time limitation to avoid blowing the multimeter’s
fuse.

10 Keysight U1281A/U1282A Quick Start Guide
10 Keysight U1281A/U1282A Quick Start Guide
Input Warning
The multimeter emits a continuous beep and the
red LED indicator lights up when:
– the test lead is inserted into the or
input terminal but the rotary switch is not set to
the correct current position. The secondary
display will show or until the
test lead is removed. The beeping will stop
automatically after 5 seconds even if the test
lead is not removed.
– the rotary switch is set to the current
measurement position but no lead is inserted
into its respective input terminal. The secondary
display will show and the warning alert
will stop after approximately 3 seconds.
A
mA

Keysight U1281A/U1282A Quick Start Guide 11
Keysight U1281A/U1282A Quick Start Guide 11
Voltage Measurements
Measuring AC voltage
A
mA COM
V
V
A
V
mV
mV
U1282A Tru e R MS M ul t i me t er
mA
Vsense
Peak Vsense
Dual
Auto
FUSED
440mA CAT III 1000V
600VCAT IV
MAX
10A MAX
FUSED
OUT
OUT
MHz
RMT
1
AC
3
2
mV
V

12 Keysight U1281A/U1282A Quick Start Guide
12 Keysight U1281A/U1282A Quick Start Guide
Using the AC low-pass filter (LPF)
WARNING
To avoid possible electric shock or personal injury,
ensure that you are aware of the voltage level
without the LPF enabled. There may be a possible
presence of hazardous voltage, and voltages
measured with the LPF enabled may be greater
than indicated. For your safety, take note of the
symbol. Disable the LPF when you have
completed your measurement.
Esc
Shift
NOTE
The LPF can improve measurement performance on
composite sine waves that are typically generated
by inverters and variable frequency motor drives.

Keysight U1281A/U1282A Quick Start Guide 13
Keysight U1281A/U1282A Quick Start Guide 13
Measuring DC voltage
A
mA COM
V
V
A
V
mV
mV
U1282A
Tru e RM S M u l t i m e te r
mA
Vsen se
Peak Vsense
Dual
Auto
FUSED
440mA CAT III 1000V
600VCAT IV
MAX
10A MAX
FUSED
OUT
OUT
MHz
RMT
1
DC
3
2
V
mV

14 Keysight U1281A/U1282A Quick Start Guide
14 Keysight U1281A/U1282A Quick Start Guide
Current Measurement
Measuring AC/DC current
WARNING
Never attempt an in-circuit current measurement
where the open-circuit potential to earth is greater
than 1000 V.
CAUTION
Current can be measured up to 440 mA (maximum)
continuously. You can measure current more than
440 mA and up to 600 mA for 20 hours maximum.
A
mA COM
V
V
A
V
mV
mV
U1282A True RMS Multimeter
mA
Vsense
Peak Vsense
Dual
Auto
FUSED
440mA CAT III 1000V
600VCAT IV
MAX
10A MAX
FUSED
OUT
OUT
MHz
RMT
1
LOAD
3
AC
2
A
mA
Esc
Shift

Keysight U1281A/U1282A Quick Start Guide 15
Keysight U1281A/U1282A Quick Start Guide 15
Measuring voltage frequency
Measuring current frequency
Measuring frequency/duty cycle/pulse width
Hz
Save
Hz
Save
Hz
Save

16 Keysight U1281A/U1282A Quick Start Guide
16 Keysight U1281A/U1282A Quick Start Guide
Frequency Counter (U1282A only)
WARNING
– Use the frequency counter for low voltage
applications. Never use the frequency counter
on AC power line systems.
– For input more than 3.6 Vpp, you are required
to use the frequency measurement mode
available under the current or voltage
measurement instead of the frequency
counter.
A
mA COM
V
V
A
V
mV
mV
U1282A
True RMS Multimeter
mA
Vsense
Peak Vsense
Dual
Auto
FUSED
440mA CAT III 1000V
600VCAT IV
MAX
10A MAX
FUSED
OUT
OUT
MHz
RMT
AC
1
4
2
3
Esc
Shift
MHz
If the reading is zero or
unstable, press to
toggle between a Hz or
MHz reading.
Range

Keysight U1281A/U1282A Quick Start Guide 17
Keysight U1281A/U1282A Quick Start Guide 17
Resistance Measurement
Removing test lead resistance
A
mA COM
V
V
A
V
mV
mV
U1282A True RMS Multimeter
mA
Vsense
Peak Vsense
Dual
Auto
FUSED
440mA CAT III 1000V
600VCAT IV
MAX
10A MAX
FUSED
OUT
OUT
MHz
RMT
1
3
2
Vsense
1
2

18 Keysight U1281A/U1282A Quick Start Guide
18 Keysight U1281A/U1282A Quick Start Guide
Continuity Tests
CAUTION
To avoid possible damage to the multimeter or to
the equipment under test, disconnect circuit power
and discharge all high-voltage capacitors before
measuring continuity. Use the DC voltage function
to confirm that the capacitor is fully discharged.
A
mA COM
V
V
A
V
mV
mV
U1282A True RMS Multimeter
mA
Vsense
Peak Vsense
Dual
Auto
FUSED
440mA CAT III 1000V
600VCAT IV
MAX
10A MAX
FUSED
OUT
OUT
MHz
RMT
ON
(closed)
OFF
(open)
4
1
3
2
Esc
Shift
If resistance < threshold, beeper
sounds and red LED indicator
lights up

Keysight U1281A/U1282A Quick Start Guide 19
Keysight U1281A/U1282A Quick Start Guide 19
Diode Tests
Forward bias
A
mA COM
V
V
A
V
mV
mV
U1282A
True RMS Multimeter
mA
Vsense
Peak Vsense
Dual
Auto
FUSED
440mA CAT III 1000V
600VCAT IV
MAX
10A MAX
FUSED
OUT
OUT
MHz
RMT
1
3
2
MHz
The beeper will emit a:
– continuous beep (for 0.3 V to 0.8 V)
– repeated beep (for <0.05 V)

20 Keysight U1281A/U1282A Quick Start Guide
20 Keysight U1281A/U1282A Quick Start Guide
Reverse bias
A
mA COM
V
V
A
V
mV
mV
U1282A
True RMS Multimeter
mA
Vsen se
Peak Vsense
Dual
Auto
FUSED
440mA CAT III 1000V
600VCAT IV
MAX
10A MAX
FUSED
OUT
OUT
MHz
RMT
1
2
MHz
3