Keysight Technologies N2893A User manual

Keysight N2893A
100 MHz Current Probe
User’s
Guide

2 N2893A 100 MHz Current Probe User’s Guide
Notices
© Keysight Technologies, Inc. 2013 - 2014,
2016, 2017, 2018
No part of this manual may be reproduced in
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tronic storage and retrieval or translation into
a foreign language) without prior agreement
and written consent from Keysight Technolo-
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international copyright laws.
Manual Part Number
N2893-97004
Edition
August 2018
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 disclaims all
warranties, either express or implied, with
regard to this manual and any information
contained herein, including but not limited
to the implied warranties of merchantability
and fitness for a particular purpose. Key-
sight shall not be liable for errors or for inci-
dental or consequential damages in
connection with the furnishing, use, or per-
formance of this document or of any infor-
mation contained herein. Should Keysight
and the user have a separate written agree-
ment with warranty terms covering the
material in this document that conflict with
these terms, the warranty terms in the sepa-
rate agreement shall control.
Technology Licenses
The hardware and/or software described in
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U.S. Government Rights
The Software is "commercial computer soft-
ware," as defined by Federal Acquisition Reg-
ulation ("FAR") 2.101. Pursuant to FAR
12.212 and 27.405-3 and Department of
Defense FAR Supplement ("DFARS")
227.7202, the U.S. government acquires
commercial computer software under the
same terms by which the software is custom-
arily provided to the public. Accordingly,
Keysight provides the Software to U.S. gov-
ernment customers under its standard com-
mercial license, which is embodied in its End
User License Agreement (EULA), a copy of
which can be found at http://www.key-
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therein, does not require or permit, among
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puter software or commercial computer
software documentation that is not custom-
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to, or otherwise provide, the government
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additional government requirements beyond
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Software. With respect to any technical data
as defined by FAR 2.101, pursuant to FAR
12.211 and 27.404.2 and DFARS 227.7102,
the U.S. government acquires no greater than
Limited Rights as defined in FAR 27.401 or
DFAR 227.7103-5 (c), as applicable in any
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Safety Notices
CAUTION
A CAUTION notice denotes a hazard. It
calls attention to an operating proce-
dure, 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 indi-
cated conditions are fully understood
and met.
WARNING
A WARNING notice denotes a hazard. It
calls attention to an operating proce-
dure, 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.
DANGER
A DANGER notice that incorrect opera-
tion presents extreme danger of acci-
dent resulting in death or serious injury
to the user.

N2893A 100 MHz Current Probe User’s Guide 3
Contents
Introduction / 5
Features / 5
Scope Compatibility / 5
Inspecting the Probe / 6
Cleaning the Probe / 6
Safety Information / 7
N2893A Components / 9
Using the Probe / 11
Making Measurements / 11
Obtaining the Best Measurement Accuracy / 12
Demagnetization and Zero Offset / 14
Protecting the Probe Against Damage Resulting from Excessive
Input / 15
Built-in Safety Function / 15
Performance Verification for N2893A / 17
Procedure / 17
Characteristics and Specifications / 21
Plots / 24
Product Markings and Labels / 26
Service Strategy / 27
To return the Probe to Keysight Technologies for Service / 27
Index

4 N2893A 100 MHz Current Probe User’s Guide
Contents

5
Keysight N2893A 100 MHz Current Probe
User’s Guide
Introduction
The N2893A is a wide-band, DC to 100 MHz, active current probe. The probe features low
noise and low circuit insertion loss. The probe has the following 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 system that includes the thin film Hall element as a detector.
- In the high frequency region, the probe operates as a current transformer.
The N2893A 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.
The probe connects to the InfiniiVision and Infiniium oscilloscopes with 1 MΩAutoProbe
interface. The oscilloscope’s AutoProbe interface provides the probe power, probe offset,
and auto configuration of probe type and attenuation setting thereby making the current
measurements as simple as those made with active voltage probes.
To use this probe 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 an easy circuit connection
- Wide bandwidth - DC to 100 MHz
- Connects directly to InfiniiVision and Infiniium oscilloscopes with 1 MΩAutoProbe
interface
- Auto degauss and offset elimination
- Auto activation of the built-in safety feature if the input current exceeds the rated
continuous maximum to prevent damage resulting from overloading.
Scope Compatibility
- 3000 X-Series oscilloscopes
- 5000, 6000 (except 100 MHz models), and 7000 Series oscilloscopes with software
version 6.10 or higher
- 9000A Series with software version 3.0 or higher
- 90000 X-Series with the N5449A adapter

6 N2893A 100 MHz Current Probe User’s Guide
N2893A Probe
Inspecting the Probe
- Inspect the shipping container for damage.
- Keep the damaged shipping container or cushioning material until the contents of the
shipment have been checked for completeness and the probe has been checked
mechanically and electrically.
- Check the accessories. If the contents are incomplete or damaged, notify your Keysight
Technologies Sales Office.
- Inspect the probe. If there is mechanical damage or defect, or if the probe does not
operate properly or pass calibration tests, notify your Keysight Technologies Sales
Office.
- If the shipping container is damaged, or the cushioning materials show signs of stress,
notify the carrier as well as your Keysight Technologies Sales Office. Keep the shipping
materials for the carrier’s inspection. The Keysight Technologies office will arrange for
repair or replacement at Keysight Technologies’ option without waiting for claim
settlement.
Cleaning the Probe
If the probe requires cleaning, disconnect it from the oscilloscope and gently clean the
external surface of the probe with a soft cloth dampened with a mild soap and water
solution.
Cleaning the Sensor Head
The presence of foreign substances such as dust on the mating surfaces of the probe’s
sensor head can cause acoustic resonance and degraded measurements, Therefore, keep
these mating surfaces clean by gently wiping with a soft cloth.
WARNING
Do not try to clean the unit using cleaners containing organic solvents such as
benzine, alcohol, acetone, ether, ketones, thinners, or gasoline. These may cause
discoloration or damage.
Make sure the probe is completely dry before reconnecting it to the oscilloscope.

N2893A Probe
N2893A 100 MHz Current Probe User’s Guide 7
Safety Information
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 safety notes.
WARNING
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
Do not install substitute parts or perform any unauthorized modification to the instrument. Only
Keysight service centers should perform repair/maintenance on the equipment.
DANGER
To avoid short circuits and accidents that could result in injury or death, use the N2893A probe only
with insulated power lines carrying 300V or less.
DANGER
Never use this sensor on uninsulated conductors. The core and shield case are not
insulated. Before clamping the insulated conductor being measured, make sure that the
insulation on the conductor is undamaged. Any damage to the insulation can cause an
electric shock.
WARNING
Do not subject the unit to vibrations or shocks during transport or handling. Be especially careful to
avoid dropping the unit.
WARNING
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.
WARNING
This unit is not constructed to be dustproof, so do not use it in a very dusty environment.

8 N2893A 100 MHz Current Probe User’s Guide
N2893A Probe
WARNING
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.
WARNING
To avoid scratching the surfaces of the Hall effect elements, keep the core section of the sensor
closed, except when clamping it around the insulated conductor to be measured.
WARNING
Before turning on the instrument, you must connect the protective earth terminal of the instrument to
the protective conductor of the (mains) power cord. The mains plug shall only be inserted in a socket
outlet provided with a protective earth contact. You must not negate the protective action by using an
extension cord (power cable) without a protective conductor (grounding).

N2893A Probe
N2893A 100 MHz Current Probe User’s Guide 9
N2893A Components
Figure 1 Probe components
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 probe
should be connected to the oscilloscope for the demagnetizing process. This process takes
about one second. During demagnetizing, a demagnetizing waveform is output. Refer to
“Demagnetization and Zero Offset" on page 14

10 N2893A 100 MHz Current Probe User’s Guide
N2893A Probe
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 oscilloscope, as the probe is
plugged into the AutoProbe interface. With an input impedance of 50Ω, accurate
measurement is not possible.
NOTE
The probe output sensitivity 0.1 V/A will be automatically selected, as the probe is
plugged into the AutoProbe interface. With a different output sensitivity, accurate
measurements are not possible.

N2893A Probe
N2893A 100 MHz Current Probe User’s Guide 11
Using the Probe
Making Measurements
1Power on the oscilloscope.
2Connect the probe to one of the scope’s channels.
Figure 2 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 Information" on page 7.
Also, take precautions mentioned in “Protecting the Probe Against Damage
Resulting from Excessive Input" on page 15.
NOTE
This probe is NOT compatible with 50Ωonly Infiniium oscilloscopes (for example, the
90000A series oscilloscopes). Use the N5449A high impedance probe adapter for use
with Infiniium 90000X Series oscilloscope. The input coupling is automatically selected
to DC, as the terminator is plugged into the AutoProbe interface.
NOTE
When the probe is connected to a scope channel, the AutoProbe interface recognizes the
probe as an N2893A and automatically configures several settings on the channel to
which the probe is connected.

12 N2893A 100 MHz Current Probe User’s Guide
N2893A Probe
3Perform the steps described in “Demagnetization and Zero Offset" on page 14.
4With the probe’s sensor head around the insulated conductor to be measured, slide the
Opening Lever of the probe into the Locked position as shown in Figure 3. While doing so,
ensure that the UNLOCK indication disappears which indicates that the sensor head is
properly closed. If the sensor head is not properly closed, accurate measurements will not
be possible.
Figure 3 Use the Opening Lever
Obtaining the Best Measurement Accuracy
To obtain the best measurement accuracy, ensure that:
- The current direction indicator on the sensor aligns with actual current direction in the
insulated conductor.
- The sensor opening lever is in the Locked position and the sensor head is properly
closed.
NOTE
Immediately after powering on, this unit may be subject to an appreciable offset drift
due to the effect of self-heating. To counteract this, allow the unit to warm up for
about 30 minutes before carrying out measurements.
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
Under certain circumstances, oscillation may occur if the probe is connected to the
AutoProbe interface while the oscilloscope is on. This does not indicate a
malfunction. Oscillation can be stopped and operation can be restored to normal by
opening and closing the sensor head.

N2893A Probe
N2893A 100 MHz Current Probe User’s Guide 13
- The conductor under test is positioned in such a way that it is in the center of the clamp
aperture.
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 4, as
appropriate.
Figure 4 Clamp Onto the Low-Voltage Side of Circuit
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.
NOTE
When performing continuous measurements, it is necessary to be aware that the zero
offset voltage will drift if the ambient temperature changes.
NOTE
At some frequencies, some sound may be produced by resonance. This has no effect
on measurements.

14 N2893A 100 MHz Current Probe User’s Guide
N2893A Probe
Demagnetization and Zero Offset
1Set the channel offset to 0V for the oscilloscope channel to which the probe is
connected.
2Ensure that the probe sensor is NOT clamped around any conductors.
3Slide the probe’s Opening Lever into the Locked position as shown in Figure 5.
Figure 5 Use the Opening Lever
4Press the probe’s DEMAG button shown in Figure 1 on page 9. 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.
5On Infiniium oscilloscopes:
aClick Setup > Probe Calibration.
bClick the AutoZero button to automatically start the demagnetization
followed by the zero offset routine.
cFollow the on-screen instructions.
6On InfiniiVision oscilloscopes:
aPress the scope’s channel button (1, 2, 3, or 4) for the channel you are using.
bClick the Probe softkey (under the display) and then press the key to
automatically start the demagnetization and zero offset process.
cFollow the on-screen instructions.
NOTE
Allow both the oscilloscope and probe to warm up for at least 30 minutes before
making these adjustments.

N2893A Probe
N2893A 100 MHz Current Probe User’s Guide 15
Protecting the Probe Against Damage Resulting from Excessive
Input
The maximum continuous input range is based on heat that is internally generated during
measurement. This range varies according to the frequency of the current being measured.
See Figure 11 on page 24 to know about the maximum continuous input range for the
N2893A probe. It is recommended not to exceed this range.
Built-in Safety Function
In such situations, when the built-in safety function is activated:
1Remove the input immediately (unclamp the sensor from the conductor being
measured or reduce the input current to zero).
2Wait until the sensor on the probe had the sufficient time to cool before resuming
operation.
WARNING
The steps and guidelines provided in this topic must be followed to ensure that your
probe is protected against any damage caused due to the input current that exceeds
the maximum continuous input range for the probe.
WARNING
In the following situations, the generated heat activates a built-in safety function in
the probe that blocks normal output to prevent probe damage resulting from heating.
- If the input current exceeds the maximum continuous input range.
- Continuous input for an extended period of time (even if the input current does not
exceed the rated continuous maximum).
- At high ambient temperatures, the built-in safety function may activate even at
current input levels below the rated continuous maximum.
WARNING
If there is continuous input of current exceeding the rated maximum or repeated
activation of the built-in safety function, it may result in damage to the unit.

16 N2893A 100 MHz Current Probe User’s Guide
N2893A Probe
Figure 6 Typical Probe Consumption
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 oscilloscope’s power supply for
safety. Quit the measurement and cycle the power of the oscilloscope, if the
shutdown occurs. The typical probe current consumption from the AutoProbe
interface is shown in Figure 6.

N2893A Probe
N2893A 100 MHz Current Probe User’s Guide 17
Performance Verification for N2893A
Use the following procedure to test the warranted Accuracy specifications for the N2893A
probe (as listed on page 21). 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.
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 N2893A probe’s output to the N1022B probe adapter’s input.
Table 1 Required Test Equipment
Description Minimum Requirements Recommended Test Equipment
Oscilloscope Bandwidth ≥ 250 MHz
Amplitude accuracy: ≤ 0.4%
Infiniium or InfiniiVision with
1MΩinput
Two Digital Multimeters - Keysight U1251B Handheld
Digital Multimeter or equivalent
DVM/DMM
AC Current Generator AC 10 Arms, 50 or 60 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 - -

18 N2893A 100 MHz Current Probe User’s Guide
N2893A Probe
Figure 7 Providing power to the N2893A probe
2Turn on the equipment.
3Wait for 20 minutes to allow the probe to warm up.
4Connect the test setup as shown in Figure 8 on page 19 as per the following substeps.
aClamp the N2893A 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.

N2893A Probe
N2893A 100 MHz Current Probe User’s Guide 19
Figure 8 Setting up AC Current Generator
5Set the DMM <2> to Vrms mode.
6As displayed in Figure 9 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.

20 N2893A 100 MHz Current Probe User’s Guide
N2893A Probe
.
Figure 9 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 N2893A probe.