Cal Test Electronics CT4071 User manual

CT4071
CT4072
User Manual
INPUT
±3.5V
6.5KV
CAT III
6.5KV
CAT III
OUTPUT
EXT.SUPPLY
INTO 1MΩ
≤ ± 8V
9V
200mA MAX
MHz Dierential Probe
Dierential Mode Common Mode
DC+AC peak
±3500 V @ 1000x
±3500 V
±1700 V @ 500x
±700 V @ 200x
±350 V @ 100x
POWER OVER RANGE
OFF
1000x
500x
200x
100x

450886-001 Rev. A caltestelectronics.com 1
CT4071 and CT4072 Differential Probes User’s Manual
© 2017 Cal Test Electronics. All rights reserved.
Unauthorized duplication of Cal Test Electronics documentation
materials is strictly prohibited. Customers are permitted to duplicate
and distribute Cal Test Electronics documentation for internal
educational purposes.

450886-001 Rev. A caltestelectronics.com 2
Safety Summary
To avoid personal injury and/or product damage, review and comply with
the following safety precautions. These precautions apply to both operating
and maintenance personnel and must be followed during all phases of
operation, service, and repair of this probe.
A WARNING statement calls attention to an operating procedure,
practice, or condition, which, if not followed correctly, could result
in injury or death to personnel.
A CAUTION statement calls attention to an operating procedure,
practice, or condition, which, if not followed correctly, could result
in damage to or destruction of parts or the entire product.
Do Not Work Alone
Do not work alone when working with high voltages.
Inspect the Probe
Inspect the probe and accessories for cracks and frayed or broken leads
before each use. If defects or damages are noted, DO NOT USE the
probe.
Dry Conditions
Hands, shoes, oor, and work bench must be dry. Avoid making
measurements under humidity, dampness, or other environmental
conditions that might affect safety.
Do Not Remove the Probe’s Casing
Removal of the probe’s casing may expose you to electric shock. If
necessary, disconnect the inputs and outputs of the probe before opening
the case.
Hazardous Contact
To avoid injury, remove jewelry such as rings, watches, and other metallic
objects. Do not touch exposed connections and components when power
is present.
Unexpected Charges
Hazardous voltages may be present in unexpected locations in circuitry
being tested when a fault condition in the circuit exists.

450886-001 Rev. A caltestelectronics.com 3
Capacitors inside the instrument may retain a charge even if the instrument
is disconnected from its source of supply.
Use Only in Ofce-Type Indoor Setting
The probe is designed to be used in ofce-type indoor environments. Do
not operate the probe:
zIn the presence of noxious, corrosive, flammable fumes, gases,
vapors, chemicals, or finely-divided particulates.
zIn environments where there is a danger of any liquid being
spilled on the probe.
zIn air temperatures exceeding the specified operating
temperatures.
zIn atmospheric pressures outside the specified altitude limits or
where the surrounding gas is not air.
Not for Critical Applications
This probe is not authorized for use in contact with the human body or for
use as a component in a life-support device or system.
Do Not Substitute Parts
Do not install substitute parts or perform any unauthorized modication to
the instrument.
Only Qualied Personnel
Only qualied personnel should use this probe. This differential voltage
probe is designed to be used by personnel who are trained, experienced,
or otherwise qualied to recognize hazardous situations and who are
trained in the safety precautions necessary to avoid possible injury when
using such a device.
Observe Maximum Working Voltage
Do not use any probe above its maximum working voltage ranges. See
“Electronic Characteristics” on page 11.
Use Proper Power Source
Do not operate this probe from a power source that applies more than the
voltage specied.

450886-001 Rev. A caltestelectronics.com 4
Must be Grounded
This probe is grounded by the shell of the BNC connector through the
grounding conductor of the power cord of the measurement instrument.
Before making connections to the input leads of this probe, ensure
that the output BNC connector is attached to the BNC connector of the
measurement instrument, and that the measurement instrument is properly
grounded. Whenever it is likely that the ground protection is impaired,
you must make the instrument inoperative and secure it against any
unintended operation.
Compliance Statements
EC Declaration of Conformity
The product conforms to the applicable European Union
requirements per IEC/EN 601010-031:2015 Safety requirements
for electrical equipment for measurement, control and laboratory use. Part
031: Safety requirements for hand-held probe assemblies for electrical
measurement and test.
EU RoHS Compliance
The probe and accessories conform to the 2011/65/EU RoHS2 Directive.
Disposal of Old Electrical & Electronic Equipment
(Applicable in the European Union and other European
countries with separate collection systems). This product is
subject to Directive 2012/19/EU of the European Parliament
and the Council of the European Union on waste electrical
and electronic equipment (WEEE), and in jurisdictions
adopting that Directive, is marked as being put on the market
after August 13, 2005, and should not be disposed of as
unsorted municipal waste. Please utilize your local WEEE
collection facilities in the disposition of this product and
otherwise observe all applicable requirements.
This probe is in compliance with IEC-61010-031 CAT II, Pollution Degree
2.

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Terms and Symbols
The following symbols appear on the product or in its documentation:
Direct current
Both direct and alternating current
Caution, possibility of electric shock
Caution, see documentation for details
Double insulation
Earth Ground
Denitions
Measurement Category II (CAT II) refers to local-level electrical distribution,
such as that provided by a standard wall outlet or plug-connected
equipment. Examples of CAT II measurements would be household
appliances, portable tools, and similar modules.
Measurement Category III (CAT III) refers to measurements on hard-wired
equipment in xed installations, distribution boards, and circuit breakers
that form part of a building wiring installation. Other examples are wiring,
including cables, bus bars, junction boxes, switches, socket outlets in the
xed installation, and stationary motors with permanent connections to
xed installations
Pollution Degree 2 refers to an operation environment where normally only
dry, non-conductive pollution occurs. Temporary conductivity caused by
condensation can be expected.
Working CAT rating is equal to that of the lowest rated element
within the test set-up.

450886-001 Rev. A caltestelectronics.com 6
1 Introduction to CT4071 and CT4072
Overview
The CT4071 and CT4072 differential probes allow safe, accurate
measurements between two voltage points where neither point is
referenced to ground. The CT4071 offers a 50 MHz bandwidth and
the CT4072 offers a 100 MHz bandwidth. Both are compatible with
oscilloscopes from all major manufacturers. The probes are exclusively
powered by the included 9 V power adapter.
Features
zMeets IEC 61010-031 safety standard
zSelectable attenuation settings of 100x, 200x, 500x, and 1000x
z50 MHz bandwidth (CT4071) and 100 MHz bandwidth (CT4072)
zUp to ±3500 V (DC + AC peak) common mode
zHigh accuracy (±2%)
zPower indicator LED
zOver range indicator LED
Initial Inspection
These units are tested prior to shipment. They are therefore ready for
immediate use upon receipt. An initial physical inspection should be
made to ensure that no damage has been sustained during shipment.
After the inspection, verify the contents of the shipment. The included
accessories for this product are:
zDifferential probe
z(2) High voltage hook probes, black & red
z(2) Alligator clips, black & red
z(2) 4 mm probes, black & red (CT4072 only)
z(2) Retractable sheathed 4 mm banana plug test leads, silicone
jacketed, black and red
zInsulated BNC cable, 100 cm
z9 V power adapter
zUser manual

450886-001 Rev. A caltestelectronics.com 7
2 Product Overview
Probe Description
INPUT
±3.5V
6.5KV
CAT III
6.5KV
CAT III
OUTPUT
EXT.SUPPLY
INTO 1MΩ
≤ ± 8V
9V
200mA MAX
MHz Dierential Probe
Dierential Mode Common Mode
DC+AC peak
±3500 V @ 1000x
±3500 V
±1700 V @ 500x
±700 V @ 200x
±350 V @ 100x
POWER OVER RANGE
OFF
1000x
500x
200x
100x
Figure 1 Front Panel Features
Test Leads,
black and red
Insulated BNC
Cable
4 mm Probe,
black and red
(CT4072 only)
High Voltage Hook
Probes,
black and red
Alligator Clips,
black and red
Power and Over
Range Indicators
(Red)
Attenuation
Selector Switch
External Power
Connection

450886-001 Rev. A caltestelectronics.com 8
3 Using the Probe
WARNING
At the time of powering on the probe, the input leads must not
be connected to an item to be tested. Never operate the probe
with the case open.
CAUTION
This probe is used to carry out differential measurements
between two points on the circuit under test. This probe is not
designed for electrically insulating the circuit under test or the
measuring instrument.
Inspection Procedure
1. Connect the BNC output connector to the vertical input of the
oscilloscope.
2. Power on the probe.
3. Set the attenuation setting on the oscilloscope to match the
probe.
4. Connect the input of probe to a function generator. Then select
a square-wave output of 10 V amplitude and 100 kHz frequency.
5. The square-wave will be displayed on the screen of the
oscilloscope. This indicates the probe is working properly.
Note that the oscilloscope should show the same voltage and
frequency as the function generator.

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Getting Started
1. Connect the BNC output connector to the vertical input of a
general purposed oscilloscope. The oscilloscope must have a
ground referenced.
2. Connect power adapter.
3. Select the proper attenuation ratio. When measuring signals
below 350 V, switch the attenuation ratio to 100x in order to get
higher resolution and less noise ratio. For voltages up to 700 V,
set the attenuation ratio to 200x, for voltages up to 1750 V set
the attenuation ratio to 500x, and for voltages up to 3500 V set
the attenuation ratio to 1000x.
4. The power indicator LED should turn on.
5. Plug the hook probes, alligator clips, or 4 mm probes (CT4072)
onto the test leads and connect the circuit to be tested.
Vertical Scale on Oscilloscope
The actual vertical scale of the oscilloscope is equal to the attenuation
factor multiplied by the range of vertical scale selected on the
oscilloscope. For example, with the probe on factor 20x and the
oscilloscope on 0.5 V/div, the real vertical scale is 20 x 0.5 = 10 V/div.
With the probe on 100x, the real vertical scale is 200 x 0.5 = 100 V/
div. These values apply when the oscilloscope is set to the typical 1
MΩ impedance input. When the scope is set to 50 Ω input, the actual
vertical scale will be doubled: 20 V/div for the 20x setting and 200 V/div
for the 200x setting. See the chart below.

450886-001 Rev. A caltestelectronics.com 10
Vertical Scale on Oscilloscope
Scope Input
Impedance
Probe
Attenuation
Setting
Actual
Attenuation
Setting
Vertical Scale
Reading on the
Oscilloscope
Actual Vertical
Scale of the
Oscilloscope
1 MΩ 20x 20x 0.5 V/div 10 V/div
1 MΩ 50x 50x 0.5 V/div 25 V/div
1 MΩ 200x 200x 0.5 V/div 100 V/div
50 Ω 20x 40x 0.5 V/div 20 V/div
50 Ω 50x 100x 0.5 V/div 50 V/div
50 Ω 200x 400x 0.5 V/div 200 V/div
Table 1 Oscilloscope Readings
4 Cleaning
This probe does not require any particular cleaning. If necessary, clean
the case with a soft cloth.
WARNING
Dry the probe thoroughly before attempting to make voltage
measurements.
CAUTION
Avoid immersing or using abrasive cleaners or solvents
containing Benzene (or similar solvents) on the probe as
these can cause deterioration of the probe body and cables.

450886-001 Rev. A caltestelectronics.com 11
5 Specications
All specications apply to the unit after a temperature stabilization time
of 20 minutes over an ambient range of 25°C ± 5°C.
Electrical Characteristics
Bandwidth 50 MHz (CT4071) 100 MHz (CT4072)
Rise Time 7 ns for 200x, 500x, & 1000x
14 ns for 100x
18 ns for 200x, 500x, & 1000x
25 ns for 100x
Attenuation 100x, 200x, 500x, 1000x
Accuracy ±2% *
AC CMRR
80 dB @ 60 Hz
60 dB @ 100 Hz
50 dB @ 1 MHz
Maximum Input Voltage
(100x)
(DC + AC peak)
±350 V
Maximum Input Voltage
(200x)
(DC + AC peak)
±700 V
Maximum Input Voltage
(500x)
(DC + AC peak)
±1750 V
Maximum Input Voltage
(1000x)
(DC + AC peak)
±3500 V
Absolute Maximum Rate
Input Voltage (each side to
ground)
2500 Vrms
Input Impedance
(Differential) 54 MΩ // 1.2 pF
Input Impedance (each side
to ground) 27 MΩ // 2.3 pF
Output Voltage Swing ±8 V (driving 1 MΩ oscilloscope input)
Offset (typical) ±5 mV
Noise (typical) 2 mVrms
Source Impedance 50 Ω
Power Supply 9 V power adapter (included)
* Accuracy based on DMM with 10 MΩ input impedance.

450886-001 Rev. A caltestelectronics.com 12
Environmental Characteristics
Operating Temp/Humidity 0°C to 50°C / 10% to 85% RH
Storage Temp/Humidity -30°C to 70°C / 10% to 90% RH
Pollution Degree Pollution Degree 2
Safety Specications
IEC 61010-031:2015 CAT II
Mechanical Characteristics
Weight 280 g
Dimensions 240 x 80 x 30 mm
BNC Cable Length 100 cm
Input Leads Length 55 cm each
Specications are subject to change without notice. To ensure the most current version of this
manual, please download the current version from our website: caltesetlectronics.com.

450886-001 Rev. A caltestelectronics.com 13
6 Voltage Derating Curve
The derating curve of the absolute maximum input voltage in common
mode is shown as follows:
Figure 2 CT4071: Derating Curve
1KHz 1MHz 10MHz10KHz 100KHz 100MHz
Frequency
5,000
500
50
Volgage (DC+ACpeak)
CT4071 Maximum Input Voltage Derating Curve
3,500
1000
500
250
150
50
1KHz 1MHz 10MHz10KHz 100KHz 100MHz
Frequency
5,000
500
50
Volgage (DC+ACpeak)
CT4072 Maximum Input Voltage Derating Curve
3,500
1000
500
250
150
50
Figure 3 CT4072: Derating Curve

450886-001 Rev. A caltestelectronics.com 14
7 Service & Warranty Information
Limited One-Year Warranty
Cal Test Electronics warrants these products to be free from defective
material or workmanship for a period of 1 year from the date of original
purchase. Under this warranty, Cal Test Electronics is limited to
repairing the defective device when returned to the factory, shipping
charges prepaid, within the warranty period.
Units returned to Cal Test Electronics that have been subject to abuse,
misuse, damage, or accident, or have been connected, installed, or
adjusted contrary to the instructions furnished by Cal Test Electronics,
or that have been repaired by unauthorized persons, will not be
covered by this warranty.
Cal Test Electronics reserves the right to discontinue models, change
specications, price, or design of this device at any time without notice
and without incurring any obligation whatsoever.
The purchaser agrees to assume all liabilities for any damages and/or
bodily injury which may result from the use or misuse of this device by
the purchaser, his employees, or agents.
This warranty is in lieu of all other representations or warranties
expressed or implied and no agent or representative of Cal Test
Electronics is authorized to assume any other obligation in connection
with the sale and purchase of this device.
Service
If you have a need for calibration or repair services, technical, or sales
support, please contact us:
22820 Savi Ranch Parkway
Yorba Linda, CA 92887
800-572-1028 or 714-221-9330
caltestelectronics.com

© 2018 Cal Test Electronics450886-001 Rev. A