R&S RT-ZC20B User manual

R&S®RT-ZC20B
Current Probe
User Manual
1802996702
Version 01
(B2ñÑ2)

This manual describes the following Rohde & Schwarz product:
●R&S®RT-ZC20B, Current Probe (1409.8233.02)
© 2022 Rohde & Schwarz GmbH & Co. KG
Muehldorfstr. 15, 81671 Muenchen, Germany
Phone: [phone] - 0
Email: [email protected]
Internet: www.rohde-schwarz.com
Subject to change – data without tolerance limits is not binding.
R&S® is a registered trademark of Rohde & Schwarz GmbH & Co. KG.
All other trademarks are the properties of their respective owners.
1802.9967.02 | Version 01 | R&S®RT-ZC20B
The following abbreviations are used in this manual: R&S®RT-ZC20B is abbreviated as R&S RT-ZC20B.

Contents
R&S®RT-ZC20B
3User Manual 1802.9967.02 ─ 01
Contents
1 Safety and regulatory information....................................... 5
1.1 Safety instructions................................................................................5
1.2 Labels on the product.......................................................................... 7
1.3 Warning messages in the documentation.......................................... 8
2 Product description...............................................................9
2.1 Key features.......................................................................................... 9
2.2 Unpacking and checking....................................................................10
2.3 Description of the probe.....................................................................11
2.3.1 Probe head............................................................................................11
2.3.2 Probe box..............................................................................................12
3 Connecting the probe..........................................................13
3.1 Handling the probe............................................................................. 13
3.2 Connecting the probe to the oscilloscope....................................... 14
3.3 Identification of the probe..................................................................15
3.4 Setting up and demagnetizing...........................................................16
3.5 Connecting the probe to the DUT......................................................17
3.6 Considerations for measurements....................................................18
4 Maintenance and service.................................................... 21
4.1 Cleaning...............................................................................................21
4.2 Contacting customer support............................................................21
4.3 Returning for servicing...................................................................... 22
4.4 Calibration interval............................................................................. 22
4.5 Storage.................................................................................................23
4.6 Disposal............................................................................................... 23

Contents
R&S®RT-ZC20B
4User Manual 1802.9967.02 ─ 01

Safety and regulatory information
R&S®RT-ZC20B
5User Manual 1802.9967.02 ─ 01
1 Safety and regulatory information
The product documentation helps you to use the product safely and efficiently.
Follow the instructions provided here and in the Chapter 1.1, "Safety instructions",
on page 5.
Intended use
The product is intended for the development, production and verification of elec-
tronic components and devices in industrial, administrative, and laboratory envi-
ronments. Use the product only for its designated purpose. Observe the operating
conditions and performance limits stated in the data sheet.
The probe is designed for usage with oscilloscopes that have a Rohde & Schwarz
probe interface. Supported Rohde & Schwarz oscilloscopes are listed in the pro-
be's data sheet.
Where do I find safety information?
Safety information is part of the product documentation. It warns you of potential
dangers and gives instructions on how to prevent personal injury or damage
caused by dangerous situations. Safety information is provided as follows:
●In Chapter 1.1, "Safety instructions", on page 5. The same information is
provided in many languages as printed "Safety Instructions". The printed
"Safety Instructions" are delivered with the product.
●Throughout the documentation, safety instructions are provided when you
need to take care during setup or operation.
1.1 Safety instructions
Products from the Rohde & Schwarz group of companies are manufactured
according to the highest technical standards. To use the products safely, follow
the instructions provided here and in the product documentation. Keep the prod-
uct documentation nearby and offer it to other users.
Use the product only for its intended use and within its performance limits. Inten-
ded use and limits are described in the product documentation such as the data
sheet, manuals and the printed "Safety Instructions". If you are unsure about the
appropriate use, contact Rohde & Schwarz customer service.
Safety instructions

Safety and regulatory information
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6User Manual 1802.9967.02 ─ 01
Using the product requires specialists or specially trained personnel. These users
also need sound knowledge of at least one of the languages in which the user
interfaces and the product documentation are available.
Reconfigure or adjust the product only as described in the product documentation
or the data sheet. Any other modifications can affect safety and are not permitted.
Never open the casing of the product. Only service personnel authorized by
Rohde & Schwarz are allowed to repair the product. If any part of the product is
damaged or broken, stop using the product. Contact Rohde & Schwarz customer
service at https://www.rohde-schwarz.com/support.
In these safety instructions, the term "product" covers instruments (oscillo-
scopes), probes and their accessories.
Choosing the operating site
Only use the product indoors. The product casing is not waterproof. Water that
enters can electrically connect the casing with live parts, which can lead to elec-
tric shock, serious personal injury or death if you touch the casing. If
Rohde & Schwarz provides accessories designed for outdoor use of your product,
e.g. a protective cover, you can use the product outdoors.
Unless otherwise specified in the data sheet, you can operate the product up to
an altitude of 2000 m above sea level.
The product is suitable for pollution degree 2 environments where nonconductive
contamination can occur. For more information on environmental conditions such
as ambient temperature and humidity, see the data sheet.
Performing measurements
Take the following measures for your safety:
●Observe all voltage and current ratings of the instrument, the probes, and the
accessories. Exceeding the allowed limits can lead to an electric shock.
Limits and ratings are marked on the products and listed in the data sheets.
Consider that the rated values depend on the frequency. The limitation curves
or values are provided in the data sheet.
●Never cause any short circuits when measuring sources with high output cur-
rents.
●When working with current probes, observe the additional operating condi-
tions specified in these safety instructions.
Safety instructions

Safety and regulatory information
R&S®RT-ZC20B
7User Manual 1802.9967.02 ─ 01
●Prevent the probe from receiving mechanical shock. Avoid putting excessive
strain on the probe cable or exposing it to sharp bends. Touching a broken
cable during measurements can cause injuries.
●Set up all probe connections to the instrument before applying power.
Working with current probes
When working with current probes, you can measure high-frequency currents or
currents that contain high-frequency components.
●Switch off the test circuit while connecting the probe.
●Do not attach the clamp to bare unisolated conductors. To avoid injury from a
short circuit, measure at a location on an insulated wire where the insulation is
sufficient for the circuit voltage.
●Connect the probe only to the secondary side of a breaker. With this measure,
you avoid injury, if a short circuit occurs.
●The following effects can cause burns and fire or damage to the measurement
site:
– Eddy current loss can cause heating of the sensor head.
– Dielectric heating can cause heating of cord insulation and other materials.
●When measuring current that includes a high-frequency component, consider
the derating characteristics of the probe. Do not measure any current that
exceeds the rated current.
Using the probes with high frequencies or strong magnetic fields may cause
the device to become abnormally hot, resulting in fire, equipment damage, or
burns.
1.2 Labels on the product
Labels on the casing inform about:
●Personal safety
●Product and environment safety
●Identification of the product
Labels on the product

Safety and regulatory information
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Table 1-1: Meaning of safety labels
Potential hazard
Read the product documentation to avoid personal injury or product damage.
Hazardous contact voltages
Do not use the probe at uninsulated live lines. Make sure to measure at sufficiently
insulated conductors. This measure protects you against electric shock, electric burn,
or arc flash.
Table 1-2: Labels regarding product and environment safety
Labeling in line with EN 50419 for disposal of electrical and electronic equipment after
the product has come to the end of its service life.
1.3 Warning messages in the documentation
A warning message points out a risk or danger that you need to be aware of. The
signal word indicates the severity of the safety hazard and how likely it will occur
if you do not follow the safety precautions.
WARNING
Potentially hazardous situation. Could result in death or serious injury if not avoi-
ded.
CAUTION
Potentially hazardous situation. Could result in minor or moderate injury if not
avoided.
NOTICE
Potential risks of damage. Could result in damage to the supported product or to
other property.
Warning messages in the documentation

Product description
R&S®RT-ZC20B
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2 Product description
The R&S RT-ZC20B is an AC/DC current probe. It allows the user to make cur-
rent measurements from DC to 100 MHz. By clamping on the conductor to be
measured, the current waveform is captured easily without interrupting the elec-
tric circuit.
Since the probe is equipped with the Rohde & Schwarz probe interface, it can be
connected to any Rohde & Schwarz base unit that is compatible with this inter-
face. When connected to the front panel of a Rohde & Schwarz oscilloscope, the
probe is controlled using the software of the oscilloscope.
2.1 Key features
The R&S RT-ZC20B is an AC/DC current probe. It allows the user to make cur-
rent measurements from DC to 100 MHz. By clamping on the conductor to be
measured, the current waveform is captured easily without interrupting the elec-
tric circuit.
Since the probe is equipped with the Rohde & Schwarz probe interface, it can be
connected to any Rohde & Schwarz base unit that is compatible with this inter-
face. When connected to the front panel of a Rohde & Schwarz oscilloscope, the
probe is controlled using the software of the oscilloscope.
The key features of the probe are the following:
●Highly accurate current detection.
●Easy current measurement without interrupting the electric circuit.
●Broadband frequency characteristics DC to 100 MHz.
●Permits measurement of low current levels.
●Easy protection function to avoid self-heating during excessive input.
●Unique thin film Hall effect element.
●Rohde & Schwarz probe interface:
– Powered by the oscilloscope - no need for an additional power supply
– Remotely controlled by the oscilloscope
Key features

Product description
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2.2 Unpacking and checking
1. Unpack the product carefully.
2. Retain the original packing material. Use it when transporting or shipping the
product later.
3. Using the delivery notes, check the equipment for completeness.
4. Check the equipment for damage.
If the delivery is incomplete or equipment is damaged, contact
Rohde & Schwarz.
Delivery notes
The delivery contains the following items:
●User manual
●Carrying case
●R&S RT-Zxx high-voltage and current probes data sheet
●Safety instructions for oscilloscopes and accessories (multilingual)
●Calibration certificate
●Documentation of calibrated values
Unpacking and checking

Product description
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11User Manual 1802.9967.02 ─ 01
2.3 Description of the probe
Figure 2-1: Overview of the R&S RT-ZC20B current probe
1 = Sensor
2 = Probe box
3 = Sensor cable
4 = Opening lever
5 = Sensor head
6 = Current direction indication
7 = UNLOCK indication
8 = Coarse adjustment trimmer
2.3.1 Probe head
The probe head consists of the following parts:
Opening lever
Operating lever for opening the sensor head. Always use this lever to open the
sensor head.
Description of the probe

Product description
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Sensor head
The sensor head clamps on the conductor being measured, and carries out the
actual current measurement. It is a precision assembly including a molded com-
ponent, 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.
See also "Handling the sensor head" on page 13.
Coarse adjustment trimmer
Use this only when adjustment is not possible within the range of the zero adjust-
ment. Use a nonconductive screwdriver (e.g. ceramic driver) for adjustment.
2.3.2 Probe box
The probe box connects the probe and the oscilloscope via the Rohde & Schwarz
probe interface. The Rohde & Schwarz probe interface contains a male precision
7 mm (276 mil) BNC connector and six pogo pin connectors. This interface pro-
vides the required supply voltage and is also used to transmit analog signals and
digital data simultaneously. All the analog voltages required by the probe are gen-
erated in the probe box.
The BNC connector is a precision component designed to reach a much higher
frequency limit when connected to an instrument with Rohde & Schwarz probe
interface.
Connect the probe only to an instrument with Rohde & Schwarz probe interface.
Never connect it to a usual BNC jack, because this can damage the probe inter-
face.
(1) Rohde & Schwarz probe interface with
7 mm (276 mil) coaxial connector and 6 pogo
pins
(2) Release knob
Description of the probe

Connecting the probe
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3 Connecting the probe
3.1 Handling the probe
The R&S RT-ZC20B can withstand a moderate amount of physical and electrical
stress. To avoid damage, treat the probe with care:
●Prevent the probe from receiving mechanical shock.
●This device should be installed and operated indoors only, between 0°C and
40°C (32°F to 104°F) and 80% RH or less.
●Avoid strain on the probe cable and route it carefully. Keep the cable away
from heat sources, as bare conductors could be exposed if the insulation
melts.
●Do not spill liquids on the probe.
Handling the sensor head
The sensor head is a precision assembly including a molded component, a ferrite
core, and a Hall effect element. To avoid damage, treat it with care:
●Do not subject it to sudden changes in ambient temperature.
●If the mating surfaces are scratched, performance may be impaired. Prevent
the mating surfaces of the sensor head from being scratched:
– Keep the sensor head closed when not in use, to avoid accumulating dust
or dirt.
– Measurements are degraded by dirt on the mating surfaces of the sensor
head, so keep the surfaces clean by gently wiping with a soft cloth.
– Keep the clamp jaws and core slits free from foreign objects, which could
interfere with clamping action.
– When the power is on, keep the core section of the sensor closed, except
when clamping it onto the conductor to be measured. The mating surface
of the core section can be scratched while it is open.
Electromagnetic compatibility
The electromagnetic compatibility (EMC) class indicates where you can operate
the product. The product is rated in EMC class B, see also data sheet under
"General data".
Handling the probe

Connecting the probe
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Class B equipment is suitable for use in:
●Residential environments
●Environments that are directly connected to a low-voltage supply network that
supplies residential buildings
3.2 Connecting the probe to the oscilloscope
The output of the probe is terminated internally. Use an Rohde & Schwarz
oscilloscope with high impedance inputs. Accurate measurement is not pos-
sible with an impedance of 50 Ω.
The probe is designed for usage with oscilloscopes that have a Rohde & Schwarz
probe interface. Supported Rohde & Schwarz oscilloscopes are listed in the pro-
be's data sheet.
1. NOTICE! Risk of circuit damage. When the current probe is connected, a
demagnetizing waveform is initially applied to the core. Rohde & Schwarz
oscilloscopes demagnetize the probe automatically when the probe is connec-
ted to the instrument.
Check that the conductor being measured is not clamped when connecting
the R&S RT-ZC20B to the oscilloscope.
2. NOTICE! Risk of damaging the probe.
Connect the probe only to an instrument with Rohde & Schwarz probe inter-
face. Never connect it to a usual BNC jack, because this can damage the
probe interface.
Connect the probe box (1) to the Rohde & Schwarz probe interface of the
oscilloscope (2).
The probe snaps in when connected properly to the port.
Connecting the probe to the oscilloscope

Connecting the probe
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Figure 3-1: Connecting the probe to the Rohde & Schwarz oscilloscope
► To disconnect the probe:
a) Press and hold the release button (3).
b) Pull the probe box away from the oscilloscope.
3.3 Identification of the probe
When the probe is connected to the oscilloscope, the oscilloscope recognizes the
probe and reads out the probe-specific parameters.
The oscilloscope settings for attenuation and offset are automatically adjusted;
and the oscilloscope switches to high impedance coupling (1 MΩ) to ensure accu-
rate measurements.
The complete probe information is shown in the probe settings dialog. For more
information, refer to the user manual of your oscilloscope.
Identification of the probe

Connecting the probe
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3.4 Setting up and demagnetizing
Before starting measurements, demagnetizing the core and a zero adjustment of
the probe are required.
To demagnetize and zero-adjust the probe:
1. Connect the R&S RT-ZC20B current probe as described in Connecting the
probe to the oscilloscope.
2. NOTICE! Risk of circuit damage. Demagnetizing causes current to flow into
the conductor, which may damage parts in the circuit to be measured. Do not
demagnetize while the R&S RT-ZC20B is clamping a conductor to be mea-
sured.
Make sure that there is no conductor in the sensor aperture.
3. NOTICE! Risk of instrument damage. When opening and closing 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.
Press the opening lever until the UNLOCK indication disappears. Close the
sensor head properly.
4. On the oscilloscope, navigate to the probe settings. For more information,
refer to the user manual of your oscilloscope.
5. Select the channel the probe is connected to.
6. Tap "DeGauss".
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 present at the output.
7. Change the "Zero adjust" value to adjust the waveform to zero position.
After demagnetizing always carry out a zero adjustment.
Tip: Some Rohde & Schwarz oscilloscopes provide a "Detect AutoZero" func-
tion to demagnetize and adjust to zero position in one step.
Tip: You can save the zero adjust value in the probe box. If you connect the
probe to another channel or to another appropriate Rohde & Schwarz oscillo-
scope, the value is read out again.
Setting up and demagnetizing

Connecting the probe
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8. If zero adjustment is not possible, turn the coarse adjustment trimmer to bring
the waveform within the range of zero adjustment (see figure 2-1 on page 11).
3.5 Connecting the probe to the DUT
1. Check that the system is safe, and that the preparations described in the pre-
ceding sections have been carried out.
2. Pull the sensor slider, so that the clamp opens.
3. Align the sensor so that the current direction indication matches the direction
of current flow through the conductor that you measure. The conductor should
be in the center of the clamp aperture because the measurement may be
affected by the position within the clamp aperture of the conductor being mea-
sured.
4. Press the opening lever until the UNLOCK indication disappears. Make sure
that the sensor head is properly closed.
If the sensor head is not properly closed, accurate measurement is not possi-
ble.
Connecting the probe to the DUT

Connecting the probe
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3.6 Considerations for measurements
Measurements of continuous input current
To avoid damage to the probe when doing measurements of continuous input cur-
rent, consider the following:
●The maximum continuous input range is based on heat that is internally gen-
erated during measurement. It varies according to the frequency of the current
being measured. Refer to the data sheet "R&S RT-Zxx high voltage and cur-
rent probes".
●The device may sustain damage from self-heating even at current levels that
are lower than the maximum rated current. The maximum rated current is a
recommended value that assumes sine-wave input under standard conditions.
Self-heating may happen if the ambient temperature increases or the mea-
surement current waveform contains other frequency components.
●If the input current exceeds a certain level, generated heat activates a built-in
safety function that blocks normal output. If this happens, remove the input
immediately (remove 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.
Continuous input of current exceeding the rated maximum or repeated activa-
tion of the safety function may result in damage to the device.
●Even if the input current does not exceed the rated continuous maximum cur-
rent, 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 current.
●Current measurement exceeding approx. 1 kHz may result in temperature rise
on the sensor-head. This is attributed to excitation loss that cannot be preven-
ted due to natural physical principles. Be careful to avoid injury, electric shock
due to short-circuits, or damage to the device that may be caused by the
increased temperature.
●Do not place any unclamped conductor with an electric current of a frequency
of 10 kHz or more near the sensor head. Current flowing in the conductor
nearby may heat up the sensor head and cause its temperature to rise, lead-
ing to damage to the sensor. For example, when one side of a go-and-return
conductor is clamped and the other side is also placed near the sensor head
as shown in the diagram, even if the electric current is lower than the consec-
Considerations for measurements

Connecting the probe
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19User Manual 1802.9967.02 ─ 01
utive maximum current, electric currents in both sides will heat up the sensor
and raise the temperature, thereby causing damage to the sensor.
Drift, oscillation, and sound
●Immediately after powering on, the probe may be subject to an appreciable
offset drift due to the effect of self-heating. Therefore, warm up the probe for
about 30 minutes before carrying out measurements.
●When performing continuous measurements, be aware that the offset voltage
drifts, depending on factors such as the ambient temperature.
●Under certain circumstances, oscillation may occur while the power supply is
on. This does not indicate a malfunction. Oscillation can be stopped and oper-
ation restored to normal by opening and closing the sensor head.
●Acoustic resonance can occur depending on the amplitude and frequency of
the measured current. This sound may also occur during demagnetizing oper-
ation, but it is not a malfunction or probe failure.
If a foreign substance such as dust is present on the contact surfaces of the
sensor head, a slight gap can occur between the upper and lower sensors,
and a resonant sound may be emitted. Clean the sensors as described in this
manual to ensure correct measurements.
●An increasing volume of the resonant sound during use may indicate that the
gap between the upper and lower sensors has increased. Since the sensor
characteristics may change, it is recommended to calibrate the device.
Considerations for measurements

Connecting the probe
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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 appropriate.
Considerations for measurements