Keysight 1147B User manual

Keysight 1147B
50 MHz Current Probe
User’s Guide

2
Notices
© Keysight Technologies, Inc. 2000- 2016, 2018
No part of this manual may be reproduced in any form
or by any means (including electronic storage and
retrieval or translation into a foreign language) with-
out prior agreement and written consent from Key-
sight Technologies, Inc. as governed by United States
and international copyright laws.
Manual Part Number
01147-97002
August 2018
Published in USA
Published by:
Keysight Technologies, Inc.
1400 Fountaingrove Parkway
Santa Rosa, CA, 95403
Warranty
The material contained in this document is provided
“as is,” and is subject to being changed, without
notice, in future editions. Further, to the maximum
extent permitted by applicable law, Keysight dis-
claims all warranties, either express or implied, with
regard to this manual and any information contained
herein, including but not limited to the implied war-
ranties of merchantability and fitness for a particular
purpose. Keysight shall not be liable for errors or for
incidental or consequential damages in connection
with the furnishing, use, or performance of this doc-
ument or of any information contained herein.
Should Keysight and the user have a separate writ-
ten agreement with warranty terms covering the
material in this document that conflict with these
terms, the warranty terms in the separate agreement
shall control.
Technology Licenses
The hardware and/or software described in this docu-
ment are furnished under a license and may be used
or copied only in accordance with the terms of such
license.
Restricted Rights Legend
If software is for use in the performance of a U.S. Gov-
ernment prime contract or subcontract, Software is
delivered and licensed as “Commercial computer
software” as defined in DFAR 252.227-7014 (June
1995), or as a “commercial item” as defined in FAR
2.101(a) or as “Restricted computer software” as
defined in FAR 52.227-19 (June 1987) or any equiva-
lent agency regulation or contract clause. Use, dupli-
cation or disclosure of Software is subject to Keysight
Technologies’ standard commercial license terms,
and non-DOD Departments and Agencies of the U.S.
Government will receive no greater than Restricted
Rights as defined in FAR 52.227-19(c)(1-2) (June
1987). U.S. Government users will receive no greater
than Limited Rights as defined in FAR 52.227-14
(June 1987) or DFAR 252.227-7015 (b)(2) (November
1995), as applicable in any technical data.
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 prod-
uct 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.

3
Contents
Introduction / 5
Safety / 6
Description of Parts / 11
Using the Probe / 13
Performance Verification for 1147B Probe / 17
Characteristics and Specifications / 21
Product Markings and Labels / 24
Service Strategy / 25

4

Introduction
5
Introduction
The 1147B is a wide-band, DC to 50 MHz, active current probe.
The probe features low noise and low circuit insertion loss. The
intelligent interface makes the probe ideal for use with the
InfiniiVision and Infiniium products using the AutoProbe interface.
This unique probe interface makes current measurements as
simple as those made with the active voltage probes.
The 1147B has two operating regions that provide a wide, flat
frequency response. In the DC to low frequency AC region, the
probe operation is based on the negative feedback of the amplifier
system that includes the thin film Hall element as a detector. In
the high frequency region, the probe operates as a current
transformer.
The 1147B is ideal for acquiring high transient time signals such
as those found in motor controllers, in switching power supplies,
and in current amplifiers driving inductive loads.
In order to use this product effectively and to ensure a long
operational life, read this user’s guide carefully and retain it for
future reference.
Features
- Highly accurate current detection
- Split-core construction allows easy circuit connection
- Broadband frequency characteristics DC to 50 MHz
- Connects directly to InfiniiVision and Infiniium scope with
1M
ΩAutoProbe interface
- Easy to degauss and offset zero calibration
- Easy protect function at excessive input
- Carrying case
Inspection
When the unit is delivered, check and make sure that it has not
been damaged in transit. If the unit is damaged, or fails to operate
according to the specifications, contact your dealer or Keysight
representative.

Safety
6
Safety
This manual provides information and warnings essential for
operating this equipment in a safe manner and for maintaining it
in safe operating condition. Before using this equipment, be sure
to carefully read the following warnings, cautions, and notes.
NOTE
This equipment is designed according to IEC 61010-1 Safety
Standards, and has been tested for safety prior to shipment.
Incorrect measurement procedures could result in injury or
death, as well as damage to the equipment. Please read this
manual carefully and be sure that you understand its contents
before using the equipment. The manufacturer disclaims all
responsibility for any accident or injury except that resulting due
to defect in its product.
WARNING
Only trained service personnel who are aware of the hazard
involved (for example, fire and electric shock) should perform
maintenance on the instrument. When maintenance can be
performed without power applied, the power cord must be
disconnected from the instrument.
WARNING
To avoid short circuits and accidents that could result in injury or
death, use the 1147B only with power lines carrying 300V or less.
WARNING
When conductors being measured carry in excess of the safe
voltage level (SELV-E) and not more than 300V, to prevent short
circuits and electric shock while the core section is open, make
sure that conductors to be measured are insulated with material
conforming to (1) Overvoltage Category I, (2) Basic Insulation
Requirements for Working Voltages of 300 V, and (3) Pollution
Degree 2. Never use this sensor on bare conductors, the core and
shield case are not insulated. If a bare conductor is inevitable to
be measured, make sure that the power to the wire must be
turned off, when opening the jaws of the probe to insert or
remove the bare wire so that 300V CAT I is always satisfied.
WARNING
Avoid damaging the cable insulation surfaces while taking
measurements.

Safety
7
WARNING
This instrument is only made for use with the Infiniium. Do not
plug the probe into any interface other than the AutoProbe
interface, of which Infiniium has a protective earthing with
double-insulation construction.
WARNING
Take the following precautions to ensure that the Infiniium does
not form a bridge between the probe and any hazardous live part:
- Isolate the AutoProbe interface to which the probe is
connected from other AutoProbe interfaces using basic insulation
conforming to the overvoltage category, working voltage, and
pollution degree requirements of the circuit being tested.
- If basic insulation requirements cannot be met between the
AutoProbe interface to which this unit is connected and other
AutoProbe interfaces of the measuring instrument, make sure
that the voltage input to the AutoProbe interfaces does not
exceed the safe voltage level (SELV-E).
- Read and observe all warnings and precautions relating to
electrical safety for the Infiniium.
WARNING
Refer to the following standards regarding the meanings of
underlined terms: IEC61010-1, IEC61010-2-031, and
IEC61010-2-032.
WARNING
To prevent electric shock, do not allow the unit to become wet
and do not use the unit when your hands are wet.
WARNING
The maximum continuous input range is based on heat that is
internally generated during measurement. Never input current in
excess of this level. Exceeding the rated level may result in
damage to the probe.
WARNING
The maximum continuous input range varies according to the
frequency of the current being measured. See Figure 10 on page
23 in “Characteristics and Specifications”.

Safety
8
WARNING
If excess current is input, generated heat activates a built-in
safety function that blocks normal output. If this happens,
remove the input immediately (unclamp the sensor from the
conductor being measured or reduce the input current to zero).
Wait until the sensor has had sufficient time to cool before
resuming operation.
WARNING
Even if the input current does not exceed the rated continuous
maximum, continuous input for an extended period of time may
result in activation of the safety circuit to prevent damage
resulting from heating of the sensor.
WARNING
At high ambient temperatures, the built-in safety circuit may
activate at current input levels below the rated continuous
maximum.
WARNING
Continuous input of current exceeding the rated maximum or
repeated activation of the safety function may result in damage
to the unit.
WARNING
Do NOT measure current such that the total probe current
consumption exceeds the allowable AutoProbe interface current
consumption. The excess current consumption causes a
temporary shutdown of the Infiniium power supply for safety.
Quit the measurement and cycle the power of the Infiniium, if the
shutdown occurs. The typical probe current consumption from
the AutoProbe interface is shown in Figure 1 on page 9.

Safety
9
Figure 1 Typical Probe Consumption
CAUTION
Do not subject the unit to vibrations or shocks during transport or
handling. Be especially careful to avoid dropping the unit.
CAUTION
Do not store the unit where it will be exposed to direct sunlight,
high temperature, high humidity, or condensation. If exposed to
such conditions, the unit may be damaged, the insulation may
deteriorate, and the unit may no longer satisfy its specifications.
CAUTION
Before using the unit, inspect it and check the operation to make
sure that the unit was not damaged due to poor storage or
transport conditions. If damage is found, contact your dealer or
Keysight representative.
CAUTION
This unit is not constructed to be waterproof or dustproof, so do
not use it in a very dusty environment or in one where it will get
wet.

Safety
10
CAUTION
The sensor head is a precision assembly including a molded
component, a ferrite core, and a Hall effect element. It may be
damaged if subjected to sudden changes in ambient
temperature, or mechanical strain or shock, and therefore great
care should be exercised in handling it.
CAUTION
The matching surfaces of the sensor head are precision ground,
and should be treated with care. If these surfaces are scratched,
performance may be impaired.
CAUTION
Do not bend or pull the sensor cable and power supply cable in
order to avoid damaging the sensor cables.
CAUTION
Gently wipe dirt from the surface of the unit with a soft cloth
moistened with a small amount of water or mild detergent. Do
not try to clean the unit using cleaners containing organic
solvents such as benzine, alcohol, acetone, ether, ketones,
thinners, or gasoline. They may cause discoloration or damage.
CAUTION
To avoid scratching the surfaces of the Hall effect elements, keep
the core section of the sensor closed, except when clamping it
around the conductor to be measured.
NOTE
Accurate measurement may be impossible in locations subject to strong
external magnetic fields, such as transformers and high-current
conductors, or in locations subject to strong external electric fields, such as
radio transmission equipment.

Description of Parts
11
Description of Parts
Figure 2 Probe Parts Identification
Opening Lever
Operating lever for opening the sensor head. Always use this lever
to open the sensor head.
Sensor Head
This clamps the conductor being measured, and carries out the
actual current measurement. It is a precision assembly including a
molded component, a ferrite core, and a Hall effect element. It
may be damaged if subjected to sudden changes in ambient
temperature, or mechanical strain or shock. Care should be
exercised when handing the sensor head.
Demagnetizing Switch (DEMAG)
This demagnetizes the core if it has been magnetized by switching
the power on and off, or by an excessive input. Always carry out
demagnetizing before measurement. The demagnetizing process
takes about one second. During demagnetizing, a demagnetizing
waveform is output. Refer to “Demagnetization and Zero
Adjustment” on page 16.

Description of Parts
12
Zero Adjustment Dial (ZERO ADJ)
Use the zero adjustment dial to correct for the effect of a voltage
offset or temperature drift on the unit. The probe should be always
be zeroed after demagnetization. Refer to “Demagnetization and
Zero Adjustment” on page 16.
Coarse Adjustment Trimmer
This adjustment should only be carried out if the probe offset is
outside the range of the zero adjustment dial.
NOTE
The output of this unit is terminated internally. The high-impedance such as
1 MΩinput impedance will be automatically selected on the Infiniium, as
the Terminator is plugged into the AutoProbe interface. With an input
impedance of 50 Ω, accurate measurement is not possible.
NOTE
The probe output sensitivity 0.1 V/A will be automatically selected, as the
Terminator is plugged into the AutoProbe interface. With an different
output sensitivity, accurate measurement is not possible.

Using the Probe
13
Using the Probe
Making Measurements
1 Power on the oscilloscope.
2 Connect the probe terminator to one of the scope channels.
Figure 3 Connecting the Probe to the Oscilloscope
WARNING
Ensure all safety warnings and precautions are followed. Before
using the probe, study the warning and precautions in
“Safety" on page 6.
NOTE
This probe is NOT compatible with 50Ωonly Infiniium oscilloscopes (for
example, the DSO80000 or 90000 series oscilloscopes). The input coupling
is automatically selected to DC, as the Terminator is plugged into the
AutoProbe interface.
NOTE
Immediately after powering on, this probe may be subject to an appreciable
offset drift due to the effect of self-heating. To counteract this, allow the
probe to warm up for about 30 minutes before carrying out measurement.
NOTE
When the probe is connected to a scope channel, the AutoProbe interface
recognizes the probe as an 1147B and automatically sets the channel to
1M
Ωinput resistance with DC input coupling.

Using the Probe
14
3 Perform the steps in “Demagnetization and Zero Adjustment" on
page 16.
4 Using the probe’s opening lever, clamp the sensor head around
the conductor to be measured as shown in Figure 4 on page 14.
Figure 4 Use the Opening Lever
5 To obtain the best accuracy, ensure that:
- The current direction indicator on the sensor aligns with actual
current direction in the conductor.
- The sensor opening lever is in the Locked position
- The cable is centered in the sensor head.
6 At high frequencies, common mode noise may affect
measurements taken on the high voltage side of circuits. If this
occurs, reduce the frequency range of the measuring instrument
or clamp onto the low-voltage side of the circuit (as shown in
Figure 5 on page 15), as appropriate.
CAUTION
Always use the opening lever when opening the probe’s sensor
head. If an upper core is forced to open when the sensor head is
locked, the open-close mechanism can be damaged.
NOTE
When performing continuous measurements, it is necessary to be aware
that the zero offset voltage will drift if the ambient temperature changes.
NOTE
Under certain circumstances, oscillation may occur if the probe is
connected to the AutoProbe interface while the Infiniium is on. This does
not indicate a malfunction. Oscillation can be stopped and operation
restored to normal by opening and closing the sensor head.

Using the Probe
15
Figure 5 Clamp Onto the Low-Voltage Side of Circuit
NOTE
At some frequencies, some sound may be produced by resonance, this has
no effect on measurements.
NOTE
Measurement accuracy is affected by the position of the conductor being
measured within the clamp aperture. The conductor should be in the center
of the clamp aperture.
NOTE
Before making a measurement, press the opening lever until the "UNLOCK"
indication disappears and check that the sensor head is properly closed. If
the sensor head is not properly closed, accurate measurement will not be
possible.
NOTE
Accurate measurement may be impossible in locations subject to strong
external magnetic fields, such as transformers and high-current
conductors, or in locations subject to strong external electric fields, such as
radio transmission equipment.

Using the Probe
16
Demagnetization and Zero Adjustment
1 Allow both the Infiniium oscilloscope and the probe to warm up for
at least 30 minutes before making these adjustments.
2 Ensure that the channel offset is set to 0V on the oscilloscope
channel to which the probe is connected.
3 Ensure that the probe sensor is NOT clamped around any
conductors.
4 Slide the probe sensor Opening Lever into the Locked position.
Refer to Figure 4 on page 14 for the location of the lever.
5 Press the DEMAG button on the terminator. A demagnetization
waveform will be displayed for a short time on the channel to
which the probe is connected. Wait until this waveform is no
longer displayed.
6 When the demagnetization waveform is no longer displayed,
adjust the ZERO ADJ control on the probe terminator to move the
trace for the channel to which the probe is connected as close as
possible to the 0V position. If the ZERO ADJ control cannot center
the trace adequately, then do the following:
aMove the ZERO ADJ control to a midrange position.
bCarefully adjust the Coarse Adjustment Trimmer on
the probe sensor to move the trace on the channel to
which the probe is connected as close as possible to
the 0V position.
cAdjust the ZERO ADJ control on the probe terminator
to move the trace for the channel to which the probe
is connected as close as possible to the 0V position.

Performance Verification for 1147B Probe
17
Performance Verification for 1147B Probe
Use the following procedure to test the warranted Accuracy
specifications (as listed on page 21) for the 1147B probe. The
recommended test interval to warrant performance of this probe is
once a year. However, you can also test the probe’s performance
as and when required using the recommended test equipment and
by following the procedure documented in this chapter.
Table 1 Required Test Equipment
Description Minimum Requirements Recommended Test Equipment
Oscilloscope Bandwidth ≥ 250 MHz
Amplitude accuracy: ≤ 0.4%
Infiniium oscilloscope with 1 MΩ
input
Two Digital Multimeters - Keysight U1251B Handheld
Digital Multimeter or equivalent
DVM/DMM
AC Current Generator AC 10 Arms, 50 Hz, sine wave
Amplitude accuracy: ≤0.3%
Keysight AC6800 or Wavetek
9100
Probe Adapter - Keysight N1022B Probe Adapter
Power Supply - Keysight 1143A Probe Offset
Control and Power Module
Test Cables (with banana jacks) - -
BNC Cable - -
BNC (F) to Banana Adapter - -
NMD 3.5mm (M) to 3.5mm (F)
adapter
--
3.5mm (M) to BNC (F) adapter - -

Performance Verification for 1147B Probe
18
Procedure
1To provide power to the probe, connect the power cord of
the N1022B probe adapter to the Power connector on the
front panel of the 1143A power module. Then connect the
1147B probe’s output to the N1022B probe adapter’s input.
Figure 6 Providing power to the 1147B probe
2Turn on the equipment.
3Wait for 20 minutes to allow the probe to warm up.
4Connect the test setup as shown in Figure 7 on page 19 as per the
following substeps.
aClamp the 1147B probe around the test cable <1> and lock
the sensor head of the probe.
bPress the DEMAG button on the probe.
cSet the digital multimeter (DMM <1>) to Arms mode.
dConnect the test cable <1> to the positive terminal of the
AC current generator's OUTPUT terminal block and to the
current input of the DMM <1>.
eConnect the test cable <2> to the negative terminal of the
AC current generator's OUTPUT terminal block and to
negative input of the DMM <1>.
fUsing the DMM <1>, set the output current of AC current
generator to 6Arms.

Performance Verification for 1147B Probe
19
Figure 7 Setting up AC Current Generator
5Set the DMM <2> to Vrms mode.
6As displayed in Figure 8 on page 20, connect a BNC cable to the:
aN1022B adapter’s output using the NMD 3.5mm (M) to 3.5mm
(F) adapter and 3.5mm (M) to BNC (F) adapter.
bDMM <2> using a BNC (F)-to-banana adapter.
This completes the test setup.

Performance Verification for 1147B Probe
20
.
Figure 8 Complete Test Setup
7Measure the current and record Vrms output of the probe as
displayed on the DMM <2>.
8Calculate gain as follows:
Gain = Vrms /Arms
Gain should be between 0.99 and 1.01 (+/-1% gain accuracy).
9Remove the test cable and AC current generator from the 1147B
probe.