Agilent Technologies 1147A User manual

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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.

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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

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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

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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

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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

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• 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.