Agilent Technologies 1147A User manual

s1
Agilent 1147A 50 MHz
Current Probe
User’s Guide
Publication number 01147- 92007
March 2012
For Safety information, Regulatory
information, and publishing information, see
the pages at the end of this book.
©Copyright Agilent Technologies 2000-
2012 All Rights Reserved.

2
1147A 50 MHz Current Probe
Introduction
The 1147A 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 1147A 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 1147A 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 1 MΩ
AutoProbe interface
• Easy to degauss and offset zero calibration
• Easy protect function at excessive input
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 Agilent
representative.
Supplied accessories:
•User’sGuide
•Carryingcase

3
Contents
Note on Safety 4
Safety Symbols 4
Safety Considerations 5
Description of Parts 7
Characteristics and Specifications 9
Measurement Characteristics 9
Power Supply Characteristics 10
Mechanical Characteristics 10
Environmental Characteristics 10
Measurement Procedure 12
Preparations for Measurement 12
Demagnetization and Zero Adjustment 13
Measurement Procedure 13
Service Strategy 17
To return the Probe to Agilent Technologies for Service 17
Calibration Testing Procedures 18
Test Equipment Required 18
Preliminary procedure 18
(1) AC Accuracy 19
Calibration Test Record 20

4
Note on Safety
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.
Safety Symbols
This User’s Guide 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.
The following symbols are used in this User’s Guide to indicate the relative
importance of cautions and warnings.
Caution refer to accompanying documents.
Indicates DC (Direct Current) or AC (Alternating
Current).
Indicates that incorrect operation presents extreme
danger of accident resulting in death or serious injury
to the user.
Indicates that incorrect operation presents significant
danger of accident resulting in death or serious injury
to the user.
Indicates that incorrect operation presents possibility
of injury to the user or damage to the equipment.
Denotes items of advice related to performance of the
equipment or to its correct operation.
WARNING
DANGER
WARNING
CAUTION
NOTE

5
Safety Considerations
Only trained service personnel who are aware of the hazard involveds
(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.
To ensure safe operation and to obtain maximum performance from the
unit, observe the cautions listed below.
• To avoid short circuits and accidents that could result in injury or
death, use the 1147A only with power lines carrying 300 V or less.
• When conductors being measured carry in excess of the safe voltage
level (SELV- E) and not more than 300 V, 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.
• Avoid damaging the cable insulation surfaces while taking
measurements.
• 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.
• Take the following precautions to ensure that the Infiniium does not
form a bridge between the probe and any hazardous live part.
1Isolate 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.
2If 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).
3Read and observe all warnings and precautions relating to electrical
safety for the Infiniium.
• Refer to the following standards regarding the meanings of underlined
terms.
IEC61010- 1
IEC61010- 2- 031
IEC61010- 2- 032
WARNING
DANGER

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• To prevent electric shock, do not allow the unit to become wet and
do not use the unit when your hands are wet.
• Do not subject the unit to vibrations or shocks during transport or
handling. Be especially careful to avoid dropping the unit.
• 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.
• 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 Agilent
representative.
• 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.
• 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.
• 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.
• Do not bend or pull the sensor cable and power supply cable in order
to avoid damaging the sensor cables.
• 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.
• 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.
• 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.
WARNING
CAUTION
NOTE

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Description of Parts
1Opening lever
Operating lever for opening the sensor head. Always use this lever to
open the sensor head.
2Sensor 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.
3Demagnetizing 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.
4Zero 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.
5Coarse adjustment trimmer
This adjustment should only be carried out if the probe offset is outside
the range of the zero adjustment dial.
Current direction indication
"UNLOCK" indication
Sensor Terminator
Sensor cable
1
2
34
5

8
• 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.
• 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.
NOTE

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Characteristics and Specifications
Measurement Characteristics
See note 1 below.
Probe Bandwidth DC to 50 MHz (-3 dB)
Accuracy (Probe Only)* ±1% of reading ±1mV
(DC or 45 Hz to 66 Hz)
Risetime2~ 7ns
Maximum current With InfiniiVision Series:
15Apeak(DC+ACpeak),15ADC,10Armscontinuous
Max. peak: 30A peak non-continuous (when two
probes are used)
30Apeak(DC+ACpeak),30ADC,24Armscontinuous
Max. peak: 32A peak non-continuous (when one
probe is used)
With Infiniium Series:
15A peak, 15 ADC, 10 Arms continuous, 30A peak
non-continuous (per each channel)
(Refer to frequency derating curve, Fig. 2)
Maximum peak current 50A (for Pulse Widths ~10µs)
Probe sensitivity 0.1V/A
Noise ~2.5mArms (with 20 MHz Bandwidth limiting)
Insertion impedance Refer to Fig. 3
Temperature coefficient ~±2% (0%C to 40%C)
Effect of external magnetic fields Equivalent to ~20mA (for a 400A/m magnetic field,
DC to 60 Hz)
Maximum circuit voltage 300VCatI(refertosafetyconsiderationsandproduct
compliances)
*This is a specification and is guaranteed at 23%C ±3%C (73%F ±5%F).
1. Requires 1MWtermination. Valid for 23%C ±3%C (73%F ±5%F), at least 30 minutes after power on.
2. Rise time is calculated as: Tr = 0.35/Bandwidth.

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Power Supply Characteristics
Mechanical Characteristics
Environmental Characteristics
See note 3 below.
DC supply voltage requirements ±12Vdc ±1V
Probe power consumption Increases with measured current.
3 VA when measuring 15 A
Maximum cable diameter 5 mm (0.2 inch)
Sensor cable length 1.5 m (59 inches)
Power cable length 1 m (39 inches)
Dimensions Sensor:
Terminator:
175 mm x 18 mm x 40 mm
6.89 in. x 0.71 in. x 1.6 in.
28 mm x 81 mm x 24 mm
1.1 in. x 3.2 in. x 0.94 in
Weight 210 g (7.4 oz.)
Accessories supplied User's Guide, storage case, calibration certificate
Operating temperature range 0%C to 40%C (32%F to 104%F)
Storage temperature range -10%C to 50%C (14%F to 122%F)
Maximum relative humidity
(operating or storage)
80% (no condensation)
Vibration 10 to 55 Hz:
55 Hz:
30 min/axis
10 octave/min
Amplitude 0.3 mm
30 min/axis
Amplitude 0.3 mm
Acceleration 17.91 m/s2
Maximum Altitude 2000 m
3. This probe is intended for indoor use only.

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Frequency [Hz]
Frequency [Hz]
Frequency [Hz]
Fig. 1 Frequency characteristic
Fig. 2 Derating according to frequency
Fig. 3 Insertion impedance
Amplitude [0dB=1V]
Maximum input current [Arms]
Insertion impedance [Ω]

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Measurement Procedure
Preparations for Measurement
1Power on the Infiniium oscilloscope.
2Connect the probe terminator to one of the scope channels.
When the probe is connected to a scope channel, the AutoProbe interface
will recognize the probe as an 1147A and will automatically make several
settings on the channel to which the probe is connected:
aThe channel input resistance will be set to 1MΩ.
bThe channel input coupling will be set to DC.
• 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

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Demagnetization and Zero Adjustment
Refer to the Description of Parts section of this manual when performing
this procedure
1Allow both the Infiniium oscilloscope and the probe to warm up
for at least 30 minutes before making these adjustments.
2Ensure that the channel offset is set to 0 V on the oscilloscope
channel to which the probe is connected.
3Ensure that the probe sensor is NOT clamped around any
conductors.
4Slide the probe sensor Opening Lever into the Locked position.
5Press 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.
6When 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 0 V position.
Measurement Procedure
Ensure all safety warnings and precautions are followed.
1Perform the Demagnetization and Zero Adjustment procedure
above.
2Clamp the sensor head around the conductor to be measured.
3To obtain the best accuracy, ensure that:
aThe current direction indicator on the sensor aligns with actual current
direction in the conductor.
bThe sensor opening lever is in the Locked position
cThe cable is centered in the sensor head.
CAUTION

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• 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.
• The maximum continuous input range varies according to the frequency
of the current being measured. See figure 2 in “Characteristics and
Specifications”
• 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.
• 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.
• At high ambient temperatures, the built- in safety circuit may activate
at current input levels below the rated continuous maximum.
• Continuous input of current exceeding the rated maximum or repeated
activation of the safety function may result in damage to the unit.
• When opening the sensor head of the probe, be sure to operate with
the opening lever. If an upper core is forced to open when the sensor
head is locked, the open- close mechanism can be damaged.
• 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 4.
WARNING
Do not Press Upper core Lock state

15
• 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 measurement.
• When performing continuous measurements, it is necessary to be aware
that the zero offset voltage will drift if the ambient temperature
changes.
• 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.
• At some frequencies, some sound may be produced by resonance, this
has no effect on measurements.
• 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.
• 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.
• 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.
• 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 waveform measuring instrument or clamp onto
the low- voltage side of the circuit (as shown in figure 5), as appropriate.
Current to be measured [A]
Current consumption [mA]
0 5 10 15
0
100
200
300
400
AC (f=50Hz)
DC
Figure 4. Typical probe consumption
NOTE

16
High
Low
Power
Source Load
Figure 5. Low-voltage side of the

17
Service Strategy
For repair and calibration testing, return the 1147A probe to an Agilent
Service Center. If the probe is under warranty, normal warranty services
apply. If the probe is not under warranty, repair costs will be applied.
To return the Probe to Agilent Technologies for Service
Call (877) 447- 7278 for further details and the location of your nearest
Agilent Technologies Service Office or go to www.agilent.com for contact
information.
1Write the following information on a tag and attach it to the probe.
• Name and address of the owner
• Probe model number
• Description of service required or failure indications
2Retain all accessories.
3Return the probe in its case or pack the probe in foam or
other shock- absorbing material and place it in a strong shipping
container. You can use the original shipping materials or order
materials from an Agilent Technologies Sales Office. If neither are
available, place 3 to 4 inches of shock- absorbing material around
the instrument and place it in a box that does not allow movement
during shipping.
4Seal the shipping container securely.
5Mark the shipping container as FRAGILE. In all correspondence,
refer to the instrument by model number and full serial number.

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Calibration Testing Procedures
These procedures are used to test the warranted specifications for the
1147A Differential Probe. The recommended calibration test interval for
the 1147A is once a year or as required. Use the equipment listed in the
“Test Equipment Required” section to complete the Calibration Testing
Procedure.
Test Equipment Required
Preliminary procedure
1Turn on the Infiniium then connect the 1147A probe to the
Infiniium. Turn on the other equipment.
2Wait 30 minutes to warm up the equipment.
Description Minimum Requirements Recommende
d test
equipment
Used at
Infiniium Bandwidth ≥ 250 MHz
Amplitude accuracy: ~0.4 %
Any Infiniium
oscilloscope
with 1MΩ
input
(1), (2), (3), (4)
Current loop wire 16 AWG, Convenient length 30 cm (1)
AC current
generator
AC 10 Arms, 50 Hz, sine wave
Amplitude accuracy: ~0.3 %
Wavetek 9100 (1)
50Ωcurrent loop N2774-23801 (4)

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(1) AC Accuracy
1Press the DEMAG button on the Terminator.
2Connect the wire to the current terminals of the AC current
generator.
3Clamp the wire with the 1147A and lock the sensor head.
4Set the Infiniium setups as follows:
Averaging: 16
Time: 5 ms/div
Vertical axis: 5 A/div
Trigger level: 0 mV
Trigger slope: Rise
Measurement mode: Vrms (Voltage)
Measurement Area: Entire Display
RMS Type: AC
Other setups: APPROPRIATE
5Set the Generator setups to AC 10 Arms, 50 Hz, and sine wave.
6Generate the wave, measure the current and record it.
7Remove the wire and the generator from the 1147A.
AC current generator Infiniium or
InfiniiVision
with 1MΩinput
Current Probe
1147A
Current loop
wire

20
Calibration Test Record
The AC Accuracy range is based on the Infiniium oscilloscope’s accuracy.
Calculate the minimum and the maximum limits corresponding to the
accuracy of your Infiniium oscilloscope.
Agilent Technologies
1147A DC to 50 MHz Current Probe
Recommended Test Interval: 1 year
Serial No.: ___________________
Certification Date: ______________
Tested By: ___________________
Certification Temperature: _______________________
Recommended Date of Next Certification: ___________
Test Limit
Minimum
Results Limit
Maximum
(1) AC Accuracy [Arms] 9.75 10.25
NOTE