x
TCP202A
50 MHz, 15 A AC/DC Current Probe
ZZZ
Instruction Manual
*P071300300*
071-3003-00
xx
TCP202A
50 MHz, 15 A AC/DC Current Probe
ZZZ
Instruction Manual
Revision A
www.tektronix.com
071-3003-00
Copyright © Tektronix. All rights reserved. Licensed software products are owned by Tektronix or its subsidiaries or suppliers, and are protected by
national copyright laws and international treaty provisions.
Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supersedes that in all previously
published material. Specifications and price change privileges reserved.
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.
Contacting Tektronix
Tektronix, Inc.
14150 SW Karl Braun Drive
P.O . B o x 5 0 0
Beaverton, OR 97077
USA
For product information, sales, service, and technical support:
In North America, call 1-800-833-9200.
Worldwide, visit www.tektronix.com to find contacts in your area.
Warranty
Tektronix warrants that this product will be free from defects in materials and workmanship for a period of one (1) year from the date of shipment. If
any such product proves defective during this warranty period, Tektronix, at its option, either will repair the defective product without charge for parts
and labor, or will provide a replacement in exchange for the defective product. Parts, modules and replacement products used by Tektronix for
warranty work may be new or reconditioned to like new performance. All replaced parts, modules and products become the property of Tektronix.
In order to obtain service under this warranty, Customer must notify Tektronix of the defect before the expiration of the warranty period and make
suitable arrangements for the performance of service. Customer shall be responsible for packaging and shipping the defective product to the service
center designated by Tektronix, with shipping charges prepaid. Tektronix shall pay for the return of the product to Customer if the shipment is to a
location within the country in which the Tektronix service center is located. Customer shall be responsible for paying all shipping charges, duties,
taxes, and any other charges for products returned to any other locations.
This warranty shall not apply to any defect, failure or damage caused by improper use or improper or inadequate maintenance and care. Tektronix
shall not be obligated to furnish service under this warranty a) to repair damage resulting from attempts by personnel other than Tektronix
representatives to install, repair or service the product; b) to repair damage resulting from improper use or connection to incompatible equipment; c) to
repair any damage or malfunction caused by the use of non-Tektronix supplies; or d) to service a product that has been modified or integrated with
other products when the effect of such modification or integration increases the time or difficulty of servicing the product.
THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THE PRODUCT IN LIEU OF ANY OTHER WARRANTIES, EXPRESS OR
IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE. TEKTRONIX' RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND EXCLUSIVE REMEDY
PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY. TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY
INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS
ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.
[W2 – 15AUG04]
Table of Contents
Generalsafety summary .................................................................................................................... v
Service safety summary................................................................................................................... viii
Compliance Information.................................................................................................................... ix
Certifications and Compliances ...................................................................................................... ix
Environmental Considerations....................................................................................................... xii
Preface..................................................................................................................................... xiii
Documentation....................................................................................................................... xiii
Conventions Used in this Manual ................................................................................................... xiii
Returning the Probe for Servicing ...................................................................................................xiv
Key Features ............................................................................................................................... 1
Connectingthe Probe ...................................................................................................................... 2
........................................................................................................................................ 2
Degaussingthe Probe ................................................................................................................ 5
Probe Controls and Features .............................................................................................................. 6
Compensation Box Controls . ........................................................................................................ 6
Probe Head Controls and Features .................................................................................................. 8
Table of Contents
TCP202A Current Probe Instruction Manual i
Table of Contents
FunctionalCheck .......................................................................................................................... 10
Basic Operation............................................................................................................................ 11
Application Examples...................................................................................................................... 13
Accessories and Options.................................................................................................................. 19
Probing Principles ......................................................................................................................... 27
Specifications.............................................................................................................................. 39
Inductance Measurements .......................................................................................................... 14
Measuring Inductor TurnsCount .................................................................................................... 17
Optional Accessories . ............................................................................................................... 22
Options............................................................................................................................... 26
Degaussing a Probewith an Unpowered Conductor in the Jaws .................................................................. 27
Measuring Differential Current....................................................................................................... 28
Extending Current Range. ........................................................................................................... 30
Increasing Sensitivity ................................................................................................................ 33
Common Mode Noise/Magnetic Field Errors........................................................................................ 34
Maximum Current Limits............................................................................................................. 35
WarrantedCharacteristics ........................................................................................................... 39
Typical Characteristics............................................................................................................... 40
Nominal Characteristics ............................................................................................................. 46
Performance Verification .................................................................................................................. 47
Equipment Required ................................................................................................................. 48
Making the DC CurrentLoop ........................................................................................................ 49
ii TCP202A Current Probe Instruction Manual
Table of Contents
Set up the Equipment ...............................................................................................................50
DC Gain Accuracy ................................................................................................................... 51
Rise Time and Bandwidth ........................................................................................................... 54
Test Record .......................................................................................................................... 56
Adjustments................................................................................................................................ 57
Equipment Required & Setup........................................................................................................ 57
Adjustment Procedures.............................................................................................................. 58
Maintenance . . ............................................................................................................................. 61
Troubleshooting...................................................................................................................... 61
Cleaning.............................................................................................................................. 62
Index
TCP202A Current Probe Instruction Manual iii
Table of Contents
iv TCP202A Current Probe Instruction Manual
General safety summary
Review the following safety precautions to avoid injury and prevent damage to this product or any products connected to it.
To avoid potential hazards, use this product only as specified.
Only qualified personnel should perform service procedures.
To avoid fire or personal injury
General safety summary
Connect and disconnect properly.
source.
Connect and disconnect properly.
Connect and disconnect properly.
circuit under test. Connect the probe reference lead to the circuit under test before connecting the probe input. Disconnect the probe
input and the probe reference lead from the circuit under test before disconnecting the probe from the measurement instrument.
Ground the product.
electric shock, the grounding conductor must be connected to earth ground. Before making connections to the input or output
terminals of the product, ensure that the product is properly grounded.
This product is indirectly grounded through the grounding conductor of the mainframe power cord. To avoid
Observe all terminal ratings.
manual for further ratings information before making connections to the product.
Do not connect a current probe to any wire that carries voltages above the current probe voltage rating.
Do not operate without covers.
TCP202A Current Probe Instruction Manual v
Do not connect or disconnect probes or test leads while they are connected to a voltage
De-energize the circuit under test before connecting or disconnecting the current probe.
Connect the probe output to the measurement instrument before connecting the probe to the
To avoid fire or shock hazard, observe all ratings and markings on the product. Consult the product
Do not operate this product with covers or panels removed.
General safety summary
Do not operate with suspected failures.
service personnel.
Avoid exposed circuitry.
Do not touch exposed connections and components when power is present.
If you suspect that there is damage to this product, have it inspected by qualified
Do not operate in wet/damp conditions.
Do not operate in an explosive atmosphere.
Keep product surfaces clean and dry.
Terms in this manual
These terms may appear in this manual:
WARNING.
CAUTION.
Warning statements identify conditions or practices that could result in injury or loss of life.
Caution statements identify conditions or practices that could result in damage to this product or other property.
Symbols and terms on the product
These terms may appear on the product:
vi TCP202A Current Probe Instruction Manual
DANGER indicates an injury hazard immediately accessible as you read the marking.
WARNING indicates an injury hazard not immediately accessible as you read the marking.
CAUTION indicates a hazard to property including the product.
The following symbol(s) may appear on the product:
General safety summary
TCP202A Current Probe Instruction Manual vii
Service safety summary
Servicesafetysummary
Only qualified personnel should perform service procedures. Read this
before performing any service procedures.
Do not service alone.
first aid and resuscitation is present.
Disconnect power.
power.
Use care when servicing with power on.
battery (if applicable), and disconnect test leads before removing protective panels, soldering, or replacing components.
To avoid electric shock, do not touch exposed connections.
Do not perform internal service or adjustments of this product unless another person capable of rendering
To avoid electric shock, switch off the instrument power, then disconnect the power cord from the mains
Dangerous voltages or currents may exist in this product. Disconnect power, remove
Service safety summary
General safety summary
and the
viii TCP202A Current Probe Instruction Manual
Compliance Information
This section lists the safety and environmental standards with which the instrument complies.
Certifications and Compliances
EC Declaration of Conformity - Low Voltage
Compliance was demonstrated to the following specification as listed in the Official Journal of the European Communities:
Low Voltage Directive 2006/95/EC.
EN 61010-1:2001. Safety requirements for electrical equipment for measurement control and laboratory use.
EN 61010-2-032:2002. Particular requirements for handheld current clamps for electrical measurement and test equipment.
U.S. Nationally Recognized Testing Laboratory Listing
UL 6010B-2-032:2003. Particular requirements for handheld current clamps for electrical measurement and test equipment.
UL 61010-1 (2ndEdition)- Safety requirements for Electrical Equipment for measurement, Control, and Laboratory use - Part
1: General Requirements
Compliance Information
TCP202A Current Probe Instruction Manual ix
Compliance Information
Canadian Certification
CAN/CSA C22.2 No. 61010-1-04. Particular requirements for electrical equipment for measurement, control, and laboratory
use. Part 1.
CAN/CSA C22.2 No. 61010-2-032:04. Particular Requirements for Hand Held Current Clamps for Electrical Measurement
and Test.
Additional Compliance
IEC 61010-1:2001. Safety requirements for electrical equipment for measurement, control, and laboratory use.
IEC 61010-2-032:2002. Particular requirements for handheld current clamps for electrical measurement and test equipment.
Equipment Type
Measurement
Pollution Degree Descriptions
A measure of the contaminates that could occur in the environment around and within a product. Typically the internal environment
inside a product is considered to be the same as the external. Products should be used only in the environment for which they
are rated.
x TCP202A Current Probe Instruction Manual
Compliance Information
Polution Degree 1. No pollution or only dry, nonconductive pollution occurs. Products in this category are generally
encapsulated, hermetically sealed, or located in clean rooms.
Polution Degree 2. Normally only dry, nonconductive pollution occurs. Occasionally a temporary conductivity that is caused by
condensation must be expected. This location is a typical office/home environment. Temporary condensation occurs only
when the product is out of service.
Polution Degree 3. Conductive pollution, or dry, nonconductive pollution that becomes conductive due to condensation. These
are sheltered locations where neither temperature nor humidity is controlled. The area is protected from direct sunshine,
rain, or direct wind.
Polution Degree 4. Pollution that generates persistent conductivity through conductive dust, rain, or snow. Typical outdoor
locations.
Pollution Degree
Pollution Degree 2 (as defined in IEC 61010-1). Note: Rated for indoor use only.
TCP202A Current Probe Instruction Manual xi
Compliance Information
Environmental Considerations
This section provides information about the environmental impact of the product.
Product End-of-Life Handling
Observe the following guidelines when recycling an instrument or component:
Equipment recycling.
contain substances that could be harmful to the environment or human health if improperly handled at the product’s end of life. To
avoid release of such substances into the environment and to reduce the use of natural resources, we encourage you to recycle this
product in an appropriate system that will ensure that most of the materials are reused or recycled appropriately.
This symbol indicates that this product complies with the applicable European Union requirements according to
Directives 2002/96/EC and 2006/66/EC on waste electrical and electronic equipment (WEEE) and batteries.
For information about recycling options, check the Support/Service section of the Tektronix Web site
(www.tektronix.com).
Production of this equipment required the extraction and use of natural resources. The equipment may
Restriction of Hazardous Substances
This product is classified as Monitoring and Control equipment, and is outside the scope of the 2002/95/EC RoHS Directive.
xii TCP202A Current Probe Instruction Manual
Preface
This manual describes the installation and operation of the TCP202A current probe. Basic probe operations and concepts are
presented in this manual. You can also access the Tektronix Web site for this document and other related information.
Documentation
Preface
To read about Use these documents
TCP202A Probe: First Time Operation, Functional Check,
Operating Basics, Specifications, Performance Verification
In-depth oscilloscope operation, user interface help, GPIB
commands
*
To access the documentation that is installed on your instrument, click
Read this Instruction Manual.
Access the online help from the Help menu on the host
instrument.
in the taskbar and select
Start
*
Programs > TekApplications
.
Conventions Used in this Manual
The following icon is used throughout this manual to indicate a step sequence.
TCP202A Current Probe Instruction Manual xiii
Preface
Returning the Probe for Servicing
If your probe requires servicing, you must return the probe to Tektronix. If the original packaging is unfit for use or not available, use
the following packaging guidelines:
Preparation for Shipment
Use a corrugated cardboard shipping
1.
carton having inside dimensions at
least one inch greater than the probe
dimensions. The box should have a carton
test strength of at least 200 pounds.
Put the probe into an antistatic bag or wrap
2.
it to protect it from dampness.
Place the probe into the box and stabilize it
3.
with light packing material.
Seal the carton with shipping tape.
4.
Refer to
5.
beginning of this manual for the shipping
address.
xiv TCP202A Current Probe Instruction Manual
Contacting Tektronix
at the
Key Features
The TCP202A current probe can make accurate measurements from DC to 50 MHz. The probe combines proven Hall-effect
technology with the Tektronix TekProbe oscilloscope interface. Key features include:
>50 MHz bandwidth, <7.0 ns rise time
AC/DC Measurement capability
3% DC Accuracy (typical)
One-button degauss/autozeroing
Direct scaling and unit readout on host
instruments
Key Features
TCP202A Current Probe Instruction Manual 1
Connecting the Probe
Connecting the Probe
The TCP202A current probe can be used with oscilloscopes that feature the Tektronix TekProbe and TekVPI interfaces.
Connecting to Oscilloscopes with
the TekProbe Interface
The TCP202A current probe mates directly
to oscilloscopes that feature the T e ktronix
TekProbe Interface.
Align the tab on the probe connector with
1.
the slot on the oscilloscope input connector
and push in the connector.
Turn the probe connector clockwise to
2.
secure the probe to the oscilloscope.
2 TCP202A Current Probe Instruction Manual
Connecting to Oscilloscopes with
the TekVPI Interface
You can also use the probe with oscilloscopes
that use the Tektronix TekVPI interface, using
the optional TPA-BNC Adapter shown.
The adapter allows TekVPI-interface
oscilloscopes to recognize TekProbe-interface
probes and to supply the necessary power,
serial communication, and offset control to the
probe.
Connect the TPA-BNC adapter to the
1.
oscilloscope. The adapter snaps in when
fully engaged.
Connect the probe to the input of the
2.
adapter.
Turn the probe connector clockwise to
3.
secure it.
Connecting the Probe
TCP202A Current Probe Instruction Manual 3
Connecting the Probe
Disconnecting the Probe
To disconnect the probe:
Turn the probe connector counterclockwise.
1.
Pull the probe away from the adapter (or
2.
instrument if directly connected).
To disconnect the adapter:
Press down the latch button.
3.
Pull the adapter away from the instrument.
4.
4 TCP202A Current Probe Instruction Manual
Degaussing the Probe
To degauss the probe, firstverifythatthe
1.
probe jaw is fully closed.
Connecting the Probe
Press the
2.
of the probe.
DEGAUSS
button on the side
Quick Tip
To maintain measurement accuracy, degauss
your probe in each of these cases:
After you turn on the measurement system
and allow a 20-minute warm-up period
Before you connect the probe to a
conductor
Whenever you subject the probe to a
strong external magnetic field
TCP202A Current Probe Instruction Manual 5
Probe Controls and Features
Probe Controls and Features
The TCP202A probe has controls in both the compensation box and at the probe head.
Compensation Box Controls
Degauss Button
To degauss the probe, do the following:
Disconnect the probe from the current
1.
source.
Close and lock the slider.
2.
Press the
3.
degauss routine.
6 TCP202A Current Probe Instruction Manual
DEGAUSS
button to initiate the
Balance Control
Probe Controls and Features
Rotate the
DC offsets in the probe output. If the balance
control cannot completely remove the DC
offset, then degauss the probe.
NOTE.
zero with the thumb wheel, a coarse balance
adjustment is accessible through an opening
on the underside of the probe head. (See
page 9, Coarse Balance Control.)
BALANCE
If you cannot set the DC offset to
control to null out small
TCP202A Current Probe Instruction Manual 7
Probe Controls and Features
Probe Head Controls and Features
Slider and Conductor Jaw
When the slider is in the locked position,
1.
you can degauss the probe and take
measurements.
Move the slider to the unlocked position to
2.
insert and remove conductors to and from
the jaw.
Thejawcanaccepta5mm(0.2in)
3.
diameter maximum conductor size.
WARNING.
force conductors larger than 5 mm (0.2 in)
diameter into the jaw.
4.
To prevent probe damage, do not
Safe handling zone – keep fingers behind
demarcations when taking measurements.
CAUTION.
changes in ambient conditions. Do not insert conductors larger than 5.0 mm (0.20 in) diameter into the probe jaw. Damage to
the probe may result.
8 TCP202A Current Probe Instruction Manual
The probe head is a precision assembly. Do not drop the probe or subject it to physical shock, strain, or sudden
Coarse Balance Control
Use this control to adjust the probe balance
when the fine-balance thumb wheel does not
have enough range to zero the probe output.
The coarse balance adjustment is accessible
through an opening on the underside of the
probe head.
First, set the thumb wheel to the midway point,
and then use an insulated, straight-edge tool
on the coarse balance adjustment to set the
offset to zero.
Probe Controls and Features
TCP202A Current Probe Instruction Manual 9
Functional Check
Functional Check
The following procedure checks that your probe is functioning properly. To verify that your probe meets the warranted specifications,
refer to the
Performance Verification
procedures. (See page 47.)
CAUTION.
conductors larger than 5.0 mm diameter into the probe jaw. Damage to the probe may result.
To check that your probe functions correctly,
do the following:
1.
2.
3.
4.
5.
10 TCP202A Current Probe Instruction Manual
The probe jaw opening accommodates insulated conductors with a diameter of 5.0 mm (0.20 in) or less. Do not insert
Connect the probe to any channel of the
oscilloscope.
Set the oscilloscope to display the probe
channel.
Press the
Clamp the probe to your circuit.
Adjust the oscilloscope or use the Autoset
function to display a stable waveform.
When you see a stable waveform, your
probe is functioning correctly.
DEGAUSS
button.
Basic Operation
Basic Operation
CAUTION.
The mating surfaces of the probe head transformer are precision-polished and should be handled with care. Measurements may
be degraded by dirt on the mating surfaces of the probe head transformer. Refer to the Maintenance section of this manual for
information on how to properly clean the probe head transformer surfaces.
1.
2.
3.
Do not force conductors larger than 5.0 mm (0.20 in) diameter into the probe jaws. Damage to the probe may result.
Check the oscilloscope display before
connecting the probe to a conductor.
If there is a DC offset, degauss and zero
the probe. (See page 5,
Probe
.)
Close and lock the probe jaw over the
conductor.
For correct polarity reading, connect the
probe so that the current flow, from positive
to negative, is aligned with the arrow on
the probe jaw.
Read the measurement on the oscilloscope
display.
Degaussing the
TCP202A Current Probe Instruction Manual 11
Basic Operation
Grounding the Probe
Use the ground lead to improve EMI rejection at high frequencies.
1.
2.
3.
Clip the ground lead to the ground post at
the bottom of the probe head.
Connect the alligator end of the clip to the
circuit ground.
Connect the probe to the circuit.
12 TCP202A Current Probe Instruction Manual
Application Examples
This section explains ways to use your probe in common troubleshooting tasks and how to extend the use of your measurement
system.
Application Examples
TCP202A Current Probe Instruction Manual 13
Application Examples
Inductance Measurements
You can use the current probe to measure the inductance of coils that have either a low-impedance or high-impedance pulse
source of a known value.
Low-Impedance Pulse Sources
This figure shows a constant-voltage pulse
generator of extremely low output impedance
connected to an inductor that has low
resistance.
Connect the inductor across the output
1.
terminals of the pulse generator.
Maintain a constant voltage across the
2.
inductor.
Clamp the current probe over one of the
3.
source leads.
If the probe impedance is a significant
NOTE.
part of the total circuit inductance, measurement
accuracy will be affected. Refer to the probe
specifications for probe insertion impedance.
14 TCP202A Current Probe Instruction Manual
Measure the current ramp. The inductance
4.
is effectively defined by the slope of the
current ramp shown here.
Calculate the inductance using the
5.
following formula:
where:
L
is the inductance in henries,
E
is the voltage of the pulse generator,
dt
is the change in time, and
di
is the change in current.
Application Examples
TCP202A Current Probe Instruction Manual 15
Application Examples
High-Impedance Pulse Sources
If the pulse source has a higher impedance of
known resistance, such that the output voltage
drops as the current increases, the inductance
of a coil can be calculated by the time constant
of the charge curve.
The current ramp shows how the values for the
inductance formula are obtained.
Use this formula to calculate the inductance
based on the current measurement:
where:
L
is the inductance in henries,
τ
is the time required for the current to rise
or fall 63.2% of the total current value, and
R
is the source resistance of the pulse
generator.
16 TCP202A Current Probe Instruction Manual
Measuring Inductor Turns Count
To obtain an approximate turns count of an
inductor, do the following:
Connect the inductor to a current limited
1.
source, as shown.
Measure the input current on one of the
2.
inductor leads.
Clamp the current probe around the
3.
inductor and note the current value.
The number of turns is equal to the ratio of coil
current to input current.
The accuracy of this method is limited by the
current measurement accuracy.
Application Examples
TCP202A Current Probe Instruction Manual 17
Application Examples
For a more precise turns count, you need a
coil with a known number of turns to use as a
reference. Do the following:
Repeat steps 1 and 2 above and make the
1.
following changes:
Insert the reference coil into the current
2.
probe.
Insert the test coil into the current probe
3.
so that the currents oppose each other
as shown. You must observe the polarity
of coil current to determine whether the
test coil has less or more turns than the
reference coil. The turns are calculated by
using the formula:
where:
N
is the number of turns in the test coil,
2
N
is the number of turns in the reference
1
coil,
I
is the measured coil current, and
m
I
is the input current.
1
18 TCP202A Current Probe Instruction Manual
Accessories and Options
This section lists the standard accessories and provides information on how to use the accessories. Specifications are provided
where appropriate so that you can choose the accessory that best fits your needs.
Probe Ground Lead
Fasten the small clip to the ground stub on
1.
the probe body.
Clip the alligator clip to your circuit.
2.
Attach the probe to your circuit.
3.
Reorder Tektronix part number:
196-3521-xx, qty. 1
Accessories and Options
TCP202A Current Probe Instruction Manual 19
Accessories and Options
Nylon Carrying Case with Pouch
and Inserts
Use the carrying case to hold the probe, the
accessories, and the Instruction Manual.
Place the probe, accessories, and manual
1.
in the carrying case.
Close the carrying case to transport the
2.
accessories to another location or for
storage.
Reorder Tektronix part number:
016-1952-xx
20 TCP202A Current Probe Instruction Manual
Instruction Manual
The instruction manual provides operating and
maintenance instructions.
Reorder Tektronix part number:
071-3003-xx
Manuals in the languages listed below
are available online for this product.
Other languages may also be available;
check the Tektronix Web site at
www.tektronix.com/manuals.
Japanese
Simplified Chinese
Accessories and Options
TCP202A Current Probe Instruction Manual 21
Accessories and Options
Optional Accessories
This section lists the optional accessories that you can purchase to help you with your probing tasks.
TPA-BNC Adapter
Use the TPA-BNC Adapter to connect the
probe to oscilloscopes that use the Tektronix
TekVPI interface.
The adapter allows TekVPI-interface
oscilloscopes to recognize TekProbe-interface
probes and to supply the necessary power,
serial communication, and offset control to the
probe.
WARNING.
not exceed the ratings of the TPA-BNC adapter;
it is not intended to be connected to voltages
above30VAC,42Vpk,or60VDC.
Order Tektronix part number:
TPA-BNC
To reduce risk of shock or fire, do
22 TCP202A Current Probe Instruction Manual
HF Current Loop
Use the high-frequency, 50 Ω current loop for
the performance verification procedures. The
BNC connector allows for easy connections to
current sources.
To use the current loop, follow the procedure
for the specific task that you are performing
(for example, Performance Verification or
Adjustments).
Order Tektronix part number:
067-2396-xx
Accessories and Options
TCP202A Current Probe Instruction Manual 23
Accessories and Options
TekVPI Calibration Fixture
This calibration fixture is required to complete
a performance verification and gain accuracy
adjustment procedures on the probe. It
provides power to the probe and routes the
probe output signal out through an SMA
connector on the back of the fixture. The signal
can then be measured with another instrument,
such as a precision DMM, to check and adjust
the gain accuracy of the probe.
Order Tektronix part number 067-1701-xx.
24 TCP202A Current Probe Instruction Manual
Deskew/Calibration Fixture
Connect this fixture to host instruments that
support the probe calibration or deskew
procedures. The deskew procedures
compensate for gain errors and timing
differences between current and voltage
probes. Refer to your oscilloscope manual or
fixture documentation for instructions.
Order Tektronix part number:
067-1686-xx
Accessories and Options
TCP202A Current Probe Instruction Manual 25
Accessories and Options
Options
Service Options
Option C3.
Option C5.
Option D1.
Option D3.
Option D5.
Option R3.
Option R5.
26 TCP202A Current Probe Instruction Manual
Calibration Service 3 years
Calibration Service 5 years
Calibration Data Report
Calibration Data Report, 3 years (with Option C3)
Calibration Data Report, 5 years (with Option C5)
Repair Service 3 years
Repair Service 5 years
Probing Principles
The following information is provided to help you use the full potential of your current probe.
Degaussing a Probe with an Unpowered Conductor in the Jaws
You can degauss your current probe while a conductor of an unpowered circuit is clamped in the jaws. The advantage of
degaussing with an unpowered circuit is that any offset from stray DC magnetic fields is compensated. Degaussing with the
conductor in the probe jaws eliminates the need to manually remove the probe.
Be certain that the conductor in the probe jaws is completely unpowered. Any current flowing through the conductor will
NOTE.
cause a residual offset in the current probe and may cause an inaccurate measurement or an error condition.
The impedance of your circuit must be higher than 10 mΩ for the degauss procedure to work. (The probe core will not saturate with
a circuit impedance of less than 10 mΩ). While degauss occurs, the probe will induce a 60 mV, 200 Hz signal in the unpowered
circuit. Your circuit must be able to absorb this induced voltage. With low impedance circuits, several amperes may be induced in
the circuit being measured. This may be of concern when you are using very small conductors.
Probing Principles
TCP202A Current Probe Instruction Manual 27
Probing Principles
Measuring Differential Current
To simplify your differential or null current
measurements, you can place two conductors
in one current probe.
WARNING.
either reduce the number of conductors you are measuring, or, if possible, take your measurement on a smaller conductor.
28 TCP202A Current Probe Instruction Manual
Do not force the slide closed. Damage to the probe may result. If you cannot close the slide around the conductor(s),
Orient the two conductors under test so
1.
that the polarities (+ and –) oppose each
other.
Clamp the current probe around the two
2.
conductors. Be careful not to pinch a
conductor in the probe jaws.
Measure the current.
3.
Conventional current flows from positive to
negative. A waveform above the baseline
indicates that the conductor with the
conventional current flow in the direction
of the probe arrow is carrying the greater
current.
Probing Principles
TCP202A Current Probe Instruction Manual 29
Probing Principles
To adjust for a current null, adjust the
4.
current in one of the conductors until the
displayed measurement is zero.
Extending Current Range
If your measurement exceeds the maximum current rating of the connected probe, you can extend the AC and DC current ranges
without exceeding specified limits by using the following methods.
WARNING.
applicable accessories. When using multiple conductors, do not exceed current limits on either conductor.
To avoid personal injury or equipment damage, do not exceed the specified electrical limits of the probe or any
Extending DC Range
If you want to measure a low-amplitude AC component that is superimposed on an extremely large steady-state DC component
(such as in a power supply), or if you want to extend the DC current range of your probe, you can add offset (bucking) current with
a second conductor.
30 TCP202A Current Probe Instruction Manual
Probing Principles
WARNING.
Do not put more than one uninsulated conductor at a time in the probe jaws. An uninsulated conductor is any
conductor without insulation or without insulation rated for the voltage present on the conductor under test.
To supply additional bucking current:
Place a second conductor that has a pure
1.
DC component of known value in the probe
jaw with the conductor under test.
Orient the second conductor so that the
2.
bucking current flows in the opposite
direction of the DC flow in the conductor
under test.
To determine measurement values, add
3.
the value of the bucking current to the
displayed measurement.
Adding a second conductor to the probe increases the insertion impedance and reduces the upper bandwidth limit of the
NOTE.
probe. Winding multiple turns further increases the insertion impedance, further reducing the upper bandwidth limit.
TCP202A Current Probe Instruction Manual 31
Probing Principles
To increase the value of the bucking current:
Wind multiple turns of the second
1.
conductor around the probe.
The bucking current is equal to the current
flowing in the conductor, multiplied by the
number of turns wound around the probe.
For example, if the second conductor has a
current of 100 mA DC and is wrapped around
the probe five times, the DC bucking current is
100 mA multiplied by 5, or 500 mA DC.
32 TCP202A Current Probe Instruction Manual
Increasing Sensitivity
If you are measuring DC or low-frequency
AC signals of very small amplitudes, you can
increase measurement sensitivity of your
current probe by doing the following:
Wind several turns of the conductor under
1.
test around the probe as shown. The
signal is multiplied by the number of turns
around the probe.
To obtain the actual current value, divide
2.
the displayed amplitude by the number of
turns.
For example, if a conductor is wrapped around
the probe three times and the oscilloscope
shows a reading of 3 mA DC, the actual current
flow is 3 mA divided by 3, or 1 mA DC.
Winding more turns around the probe increases the insertion impedance and reduces the upper bandwidth limit of the probe.
NOTE.
Probing Principles
TCP202A Current Probe Instruction Manual 33
Probing Principles
Common Mode Noise/Magnetic Field Errors
Common-mode noise at high frequencies and
strong magnetic fields on the supply side of
your circuit can cause measurement errors. To
avoid this:
Measure on the low or ground side of your
1.
circuit.
Orient the probe to measure conventional
2.
current flow.
34 TCP202A Current Probe Instruction Manual
Maximum Current Limits
Current probes have three maximum current ratings: pulsed, continuous, and Ampere-second product. Exceeding any of these
ratings can saturate the probe core, which magnetizes the core and causes measurement errors. Refer to the specifications for the
maximum current ratings of the probe. (See Table 2 on page 40.)
Probing Principles
Maximum Pulsed Current (I
maxP
)isthe
maximum peak value of pulsed current the
probe can accurately measure, regardless
of how short (within bandwidth limitations)
the pulse duration is.
Maximum Continuous Current (I
maxC
)isthe
maximum current that can be continuously
measured at DC or at a specified AC
frequency. The maximum continuous
current value is derated with frequency;
as the frequency increases, the maximum
continuous current rating decreases.
TCP202A Current Probe Instruction Manual 35
Probing Principles
Ampere-Second Product is the maximum
width of pulsed current that you can
measure when the pulse amplitude is
between the maximum continuous and
maximum pulsed current specifications.
The maximum continuous specification
varies by frequency.
To determine if your measurement exceeds
the Ampere-second product, you must first
determine the maximum allowable pulse width
or maximum allowable pulse amplitude, as
described in the following section.
NOTE.
current, or Ampere-second product rating of the probe. Exceeding these ratings can magnetize the probe and cause measurement
errors.
Always degauss the probe after measuring a current that exceeds the maximum continuous current, maximum pulsed
36 TCP202A Current Probe Instruction Manual
Maximum Allowable Pulse Width
To determine the maximum allowable pulse
width do the following:
Measure the peak current of the pulse.
1.
Divide the Ampere-second (or
2.
Ampere-microsecond) specification
for the range setting of the TCP202A probe
by the measured peak current of the pulse:
The quotient is the maximum allowable
pulse width (PW
Check that the pulse width at the 50% point
3.
of the measured signal is less than the
calculated maximum allowable pulse width
).
(PW
max
max
).
Probing Principles
TCP202A Current Probe Instruction Manual 37
Probing Principles
Maximum Allowable Pulse Amplitude
To determine the maximum allowable pulse
amplitude do the following:
Measure the pulse width at the 50% points.
1.
Divide the Ampere-second (or
2.
Ampere-microsecond) specification
for the TCP202A probe by the pulse width.
The quotient is the maximum allowable
pulse amplitude; the peak amplitude of the
measured pulse must be less than this
value.
For example, the TCP202A probe has a
maximum Ampere-second product of 500 A-μs.
If a pulse measured with the probe has a width
of 11 μs, the maximum allowable peak current
would be 500 A-μs divided by 11 μs, or 45.5 A.
38 TCP202A Current Probe Instruction Manual
Specifications
The specifications in the tables in this section are valid under the following conditions:
The probe has been calibrated at an ambient temperature of 23 °C ±5 °C.
The probe is connected to a host instrument with an input impedance of 50 Ω.
The probe must have a warm-up period of at least 20 minutes and be in an environment that does not exceed the limits
described. (See Table 1.)
Specifications for the TCP202A current probe fall into three categories: warranted, typical, and nominal characteristics.
Warranted Characteristics
Warranted characteristics describe guaranteed performance within tolerance limits or certain type-tested requirements. Warranted
characteristics have checks in the
Table 1: Warranted electrical characteristics
Characteristic Description
DC gain accuracy <3% (typical <1% at +23 °C, ±5 °C)
Rise time (10% to 90%)
Bandwidth
Performance Verification
≤7.0 ns
DC to 50 MHz
Specifications
section.
TCP202A Current Probe Instruction Manual 39
Specifications
Typical Characteristics
Typical characteristics describe typical but not guaranteed performance.
Table 2: Typical electrical characteristics
Characteristic Description
Maximum continuous current – DC and
low frequency (See Figure 3 on page 43.)
Maximum peak current (See Figure 3 on
page 43.)
Displayed RMS noise ≤2.5 mA RMS (limit measurement bandwidth to 20 MHz)
Insertion impedance
Signal delay
Maximum voltage on bare wire
Maximum voltage on insulated wire
Maximum Amp·Second product
15 A DC + peak AC
50 A maximum peak pulse (pulse width <10 us)
(See Figure 2 on page 42.)
~17 ns
150 V CAT II
300 V CAT II
500 μA-s
40 TCP202A Current Probe Instruction Manual
Figure 1: Frequency derating at 25 °C and 50 °C ambient temperatures
Specifications
TCP202A Current Probe Instruction Manual 41
Specifications
Figure 2: T ypical input impedance versus frequency
42 TCP202A Current Probe Instruction Manual
Figure 3: Maximum peak pulse versus pulse width
Specifications
TCP202A Current Probe Instruction Manual 43
Specifications
Table 3: Environmental characteristics
Characteristic Description
Temperature
Humidity
Altitude
Table 4: Typical mechanical characteristics
Characteristic Description
Dimensions, compensation box
Dimensions, probe head
Dimensions, cable length
Unit weight
Operating: +5to+50°C(+41to+122°F)
Nonoperating: -10 to +50 °C (+14 to +122 °F)
Operating: 5-95% RH, tested at +30 °C to +50 °C (+86 °F to +122 °F)
Nonoperating: 5-95% RH, tested at +30 °C to +60 °C (+86 °F to +140 °F)
Operating: Up to 3000 meters (10,000 feet)
Nonoperating: Up to 12,192 meters (40,000 feet)
107mm×41mm×26mm(4.2in×1.6in×1.0in)
197 mm × 1.6 cm × 3.2 cm (7.77 in × 0.625 in × 1.25 in)
2 m (79 in) (from the probe head to the compensation box)
1.550 g (3.44 lbs) (probe, accessories, and packaging)
44 TCP202A Current Probe Instruction Manual
Figure 4: Probe dimensions
Specifications
TCP202A Current Probe Instruction Manual 45
Specifications
Nominal Characteristics
Nominal characteristics describe guaranteed traits, but the traits do not have tolerance limits.
Table 5: Nominal electrical characteristics
Characteristic Description
Input coupling
Current range
Termination
Compatibility Oscilloscopes equipped with the TekProbe interface
DC
15 A
Terminate output into 50 Ω
Oscilloscopes equipped with the TekVPI interface, when used with the TPA-BNC
adapter (See page 22,
TPA-BNC Adapter
.)
46 TCP202A Current Probe Instruction Manual
Performance Verification
The procedures that follow verify the warranted specifications of the probe listed below. The recommended calibration interval is
one year.
DC gain accuracy
Rise time
Bandwidth
Perform the following verification procedures in the order listed.
Performance Verification
TCP202A Current Probe Instruction Manual 47
Performance Verification
Equipment Required
The equipment required for the performance verification procedures are listed below.
Table 6: Test equipment
Description and quantity Performance requirement Recommended example
Oscilloscope TekVPI interface, 500 MHz or greater bandwidth Tektronix DPO4000
High amplitude pulse generator Rise time <500 ps, pulse width >100 ns, amplitude
Calibrator DCV: 0.2% accuracy, 0 to ±1.5 V, square wave output
Digital Multimeter (DMM) 0.02% accuracy Tektronix DMM4040/4050
Adapter
Adapter
DC current loop 5 turns 18 AWG coated wire on 3 inch form See instructions that follow
HF current loop
Adapter
Adapter
BNC cable 50 Ω, 0.76 m (30 in) length
1
Nine-digit part numbers (xxx-xxxx-xx) are Tektronix part numbers.
Picosecond Labs 2600
>10 Vpp into 50 Ω
Fluke 9100
ACA: 0.25% accuracy, 0 to ±6 A, square wave output
TekVPI calibration/verification adapter
067-1701-xx
TekVPI-to-BNC interface adapter TPA-BNC
50 Ω ±0.5%, BNC male
BNC-to-dual banana plug
SMA male-to-BNC-female
067-2396-xx
103-0090-xx
015-1018-xx
012-0117-xx
1
48 TCP202A Current Probe Instruction Manual
Making the DC Current Loop
Construct the loop using #18 coated wire and a cylindrical form approximately 3 inches in diameter:
exactly
Wind
1.
around the form.
Scrape about a half-inch of coating off of
2.
the ends of the wire.
5 turns of #18 coated wire
Performance Verification
Ensure that the current loop has exactly 5 turns. A significant error will result for each turn variance from 5 turns.
NOTE.
TCP202A Current Probe Instruction Manual 49
Performance Verification
Set up the Equipment
Use the following procedure to set up and warm up the equipment to test the probe.
Turn on the oscilloscope.
1.
Connect the probe to any channel of the
2.
oscilloscope.
Press the
3.
Set the oscilloscope coupling to DC.
4.
Power on the current source and the pulse
5.
generator.
Allow 20 minutes for the equipment to
6.
warm up.
Photocopy the test record and use it to
7.
record the test results. (See page 56.)
50 TCP202A Current Probe Instruction Manual
DEGAUSS
button.
DC Gain Accuracy
This test checks the DC gain accuracy of the probe. If the measurements are out of the specified limits in the test record, refer to
Adjustments
the
Connect a BNC-to-Dual Banana adapter to
1.
the digital multimeter (DMM) input.
Connect the SMA M-to-BNC-F adapter
2.
to the SMA output of the TekVPI
Calibration/Verification adapter.
Connect the BNC cable between
3.
the BNC adapter on the TekVPI
Calibration/Verification adapter and the
BNC adapter attached to the DMM.
Connect the TekVPI Calibration/Verification
4.
adapter to any channel (1–4) of the
oscilloscope.
Connect the TPA-BNC adapter to the
5.
TekVPI Calibration/Verification adapter.
The adapters are only used to supply
NOTE.
power to the probe; measurements are taken
on the DMM.
section. (See page 57.)
Performance Verification
TCP202A Current Probe Instruction Manual 51
Performance Verification
Connect the probe to the TPA-BNC adapter
6.
and then make sure that the probe jaw is in
the locked position.
Degauss the probe by pressing the
7.
DEGAUSS
Connect the 5-turn current loop to the
8.
current source, and then clamp the current
probe around the 5-turn current loop as
shown. The arrow indicator on the probe
should point away from the (+) terminal of
the current source.
Set the current source output to +0.50 A.
9.
Set the DMM to measure DC volts, on
10.
≥2 volt range (or use Autoset).
Enable the output of the current source.
11.
button.
52 TCP202A Current Probe Instruction Manual
Record the exact measurement of the
12.
DMM as M1.
Set the current source output to -0.50 A.
13.
Record the exact measurement of the
14.
DMM as M2.
Compute the % Error using the measured
15.
amplitude values and the formula shown.
For example, you might measure values of
0.250 V for M1 and –0.255 V for M2. With
an expected output voltage (Ve) of 0.250 V,
compute the % Error as shown.
Record the computed %Error values in the
16.
Test Record.
Disable the calibrator output.
17.
Performance Verification
Test current = ±2.500 A (±0.50 A source output x 5 coil turns)
Expected output voltage (Ve) = 0.250 V
Example:
TCP202A Current Probe Instruction Manual 53
Performance Verification
Rise Time and Bandwidth
This procedure verifies that the probe meets the rise time specification. The bandwidth of the probe is then calculated using the
measured probe rise time.
Connect the BNC cable to the output of the
1.
pulse generator.
Connect the other end of the BNC cable to
2.
the HF current loop.
Set the pulse generator output and pulse
3.
width to maximum.
Set the oscilloscope:
4.
Vertical sensitivity to 200 mA/div
Horizontal to 20 ns/div
Trigger at 50%
Averaging on (32)
Coupling to DC
Automeasurement to Rise Time
54 TCP202A Current Probe Instruction Manual
Connect the probe to any channel (1–4)
5.
of the oscilloscope, and then degauss the
probe.
Clamp the current probe around the HF
6.
current loop. Verify that the arrow-shaped
indicator on the probe points away from the
pulse generator.
Record the rise time measurement in the
7.
Test Record.
Calculate the probe bandwidth using the
8.
measured rise time in the following formula:
Record the calculated bandwidth value in
9.
the test record.
End of procedures.
Performance Verification
TCP202A Current Probe Instruction Manual 55
Performance Verification
Test Record
Probe Model/Serial Number:
Temperature:
Date of Calibration:
Performance test
DC gain accuracy
Rise time <7.0 ns NA 7.0 ns
Bandwidth >50 MHz 50 MHz NA
Expected output Minimum Incoming
0.250 V 0.2425 V 0.2575 V
Certificate Number:
RH %:
Technician:
Outgoing
Maximum
56 TCP202A Current Probe Instruction Manual
Adjustments
The procedures that follow describe adjustments to the probe to bring the DC gain accuracy performance within the warranted
specifications.
Equipment Required & Setup
Adjustments
Refer to the equipment list and the DC gain accuracy procedure in the
also need the tools listed below to complete the adjustments.
Table 7: Adjustment tools
Item Description Tektronix part number
Release tool
Adjustment tool
CAUTION.
handling the probe
TCP202A Current Probe Instruction Manual 57
To avoid ESD damage to the probe, use an antistatic wrist strap and work at a static-approved workstation when
Compensation box cover removal tool
Insulated, slotted (straight) head
Performance Verification
to set up the equipment. You
003-1383-xx
003-1433-xx
Adjustments
Adjustment Procedures
You mu s t first remove the cover from the compensation box to access the gain adjustment.
Removing the Compensation Box
Cover
Press the release tool pins into the
1.
compensation box cover catches and
gently lift the cover off a small distance.
Hold the open edge apart, and use the tool
2.
to open the other side of the compensation
box.
With both sides of the box open,
3.
gently separate the two halves of the
compensation box.
58 TCP202A Current Probe Instruction Manual
Adjusting the Gain
Carefully lift the back edge of the circuit
1.
board to access the gain adjustment.
Set up the probe for the DC accuracy test.
2.
(See page 51,
Set the current source output to +0.50 A.
3.
Adjust the probe output to 250 mV, ±5 mV.
4.
Disconnect the probe from the setup.
5.
DC Gain Accuracy
Adjustments
.)
TCP202A Current Probe Instruction Manual 59
Adjustments
Replacing the Compensation Box
Cover
Align the TekProbe interface and the strain
1.
relief notches with the tabs on the cover.
Press the catches of the cover in and lower
2.
the cover.
Slide the tab into the notch.
3.
Firmly press the pieces together until the
4.
cover catches snap into place.
60 TCP202A Current Probe Instruction Manual
Maintenance
This section contains maintenance information for your probe.
Troubleshooting
The TCP202A current probe is designed to work with all oscilloscopes equipped with the TekProbe interface, and with the TekVPI
interface when used with the TPA-BNC adapter. If some of the probe functions do not work properly, an error condition may exist,
and the oscilloscope may alert you to the error or status conditions affecting the probe. See the following table.
Table 8: Probe troubleshooting
Maintenance
Symptom
The oscilloscope does not display a
current measurement from the probe
An error message displays on the
oscilloscope
TCP202A Current Probe Instruction Manual 61
Possible cause
The conductor jaw is not fully closed: Close the jaw completely.
The oscilloscope channel that the probe is connected to may not be selected.
Check your connections and oscilloscope settings.
The oscilloscope channel may be bad: Try another channel or another oscilloscope.
If the probe functions correctly on another channel or oscilloscope, the contacts on
the input channel that exhibits the problem may need to be cleaned. Refer to your
oscilloscope manual for the proper cleaning procedure.
If the probe does not work on another channel or oscilloscope, the probe is
defective, and must be returned to Tektronix for repair.
The message will describe the cause and solution. For example, if the
degauss needed
message appears, perform the degauss procedure.
Probe
Maintenance
Cleaning
Protect the probe from adverse weather conditions. The probe is not waterproof.
CAUTION.
the probe during exterior cleaning.
Do not use chemical cleaning agents; they may damage the probe. Avoid using chemicals that contain benzine, benzene,
toluene, xylene, acetone, or similar solvents.
Clean the exterior surfaces of the probe with a dry, lint-free cloth or a soft-bristle brush. If dirt remains, use a soft cloth or swab
dampened with a 75% isopropyl alcohol solution and rinse with deionized water. A swab is useful for cleaning narrow spaces on the
probe, use only enough solution to dampen the swab or cloth. Do not use abrasive compounds on any part of the probe.
62 TCP202A Current Probe Instruction Manual
To prevent damage to the probe, do not expose it to sprays, liquids, or solvents. Avoid getting moisture inside
Index
Index
A
Accessories
optional, 19, 22
Adjustments, 57
Amp-second product, 36
Application examples, 13
B
Basic operation, 11
Bucking current, 30
C
Cleaning, 62
Common mode noise, 34
Connect the probe, 2
Current limitations
amp-second product, 36
maximum continuous, 35
maximum pulsed, 35
Current loop, 49
D
DC
gain accuracy check, 51
Degaussing, 5
while connected to a
conductor, 27
Differential current, 28
Documentation, xiii
E
Equipment required
adjustments, 57
performance verification, 48
Equipment setup, 50
Extending the current range of the
probes, 30
F
Features, 1
Frequency derating, 35
Functional check, 10
G
Grounding the probe, 12
I
Increasing bucking current, 30
Increasing probe sensitivity, 33
Indicators, 6
J
Jaw, 8
M
Magnetic field errors, 34
Maintenance, 61
Maximum
allowable pulse amplitude, 38
allowable pulse width, 37
continuous current rating, 35
pulsed current rating, 35
Measuring current
current nulls, 28
differential current, 28
TCP202A Current Probe Instruction Manual 63
Index
N
Null current, 28
O
Options, 26
P
Performance verification, 47
Probe
connecting, 2
controls and indicators, 6
extending the current range, 30
grounding, 12
increasing the current limit, 30
maximum current limits, 35
saturation, 35
R
Record, test, 56
Related documentation, xiii
Rise time check, 54
S
Safety Summary, v
Service options, 26
Slider and conductor jaw, 8
Specifications, 39
environmental, 44
mechanical, 44
nominal, 46
typical, 40
warranted, 39
T
TekVPI, 3
Test record, 56
Troubleshooting, 61
64 TCP202A Current Probe Instruction Manual
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