Rohde & Schwarz RT-ZC31 User manual

R&S®RT-ZC31
Current Probe
User Manual
1801494902
Version 03
(B1aa2)

This manual describes the following R&S products:
●R&S®RT-ZC31, Current Probe (1801.4932.02)
●R&S®RT-ZA13, Probe Power Supply (1409.7789.02)
© 2023 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.
Trade names are trademarks of the owners.
1801.4949.02 | Version 03 | R&S®RT-ZC31
The following abbreviations are used in this manual: R&S®RT-ZC31 is abbreviated as R&S RT-ZC31.

Contents
R&S®RT-ZC31
3User Manual 1801.4949.02 ─ 03
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 Product overview.................................................................................. 9
2.2 Key features.......................................................................................... 9
2.3 Unpacking and checking......................................................................9
2.4 Description of the Probe.................................................................... 10
2.4.1 Probe Overview.................................................................................... 10
2.4.2 Termination Unit.................................................................................... 11
2.4.3 Junction Box (Keys, LEDs)................................................................... 13
2.4.4 Sensor...................................................................................................15
3 Connecting the probe..........................................................17
3.1 Handling the probe............................................................................. 17
3.2 Connecting the probe to the power supply......................................18
3.3 Connecting the probe to the oscilloscope....................................... 19
3.4 Setting up and demagnetizing...........................................................20
3.5 Connecting the probe to the DUT......................................................22
3.6 Disconnecting the probe from the DUT............................................ 24
3.7 Considerations for measurements....................................................25
4 Features and characteristics.............................................. 28
4.1 How to measure current accurately.................................................. 28
4.2 Protection mode..................................................................................28

Contents
R&S®RT-ZC31
4User Manual 1801.4949.02 ─ 03
4.3 Typical characteristics........................................................................30
4.3.1 Frequency characteristics..................................................................... 31
4.3.2 Frequency derating curve..................................................................... 31
4.3.3 Input impedance................................................................................... 32
4.3.4 Consumption current.............................................................................32
4.3.5 Influence of common-mode voltage......................................................33
5 Troubleshooting...................................................................34
5.1 Possible device errors........................................................................34
5.2 LED display errors.............................................................................. 35
6 Maintenance and service.................................................... 39
6.1 Cleaning...............................................................................................39
6.2 Contacting customer support............................................................39
6.3 Returning for servicing...................................................................... 40
6.4 Calibration interval............................................................................. 40
6.5 Storage and transport........................................................................ 41
6.6 Disposal............................................................................................... 41
7 R&S RT-ZA13 probe power supply.................................... 42

Safety and regulatory information
R&S®RT-ZC31
5User Manual 1801.4949.02 ─ 03
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.
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.
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.
Safety instructions

Safety and regulatory information
R&S®RT-ZC31
6User Manual 1801.4949.02 ─ 03
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.
●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.
Safety instructions

Safety and regulatory information
R&S®RT-ZC31
7User Manual 1801.4949.02 ─ 03
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
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.
Labels on the product

Safety and regulatory information
R&S®RT-ZC31
8User Manual 1801.4949.02 ─ 03
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-ZC31
9User Manual 1801.4949.02 ─ 03
2 Product description
2.1 Product overview
The R&S RT-ZC31 is a clamp-on current probe that features high current-detec-
tion sensitivity and broad frequency band. The probe uses three current ranges to
detect current waveforms from a few hundred µA to 50 A.
By clamping on the conductor to be measured, the current waveform is captured
easily without interrupting the electric circuit.
2.2 Key features
●The sensor head has a clamp design that makes it possible to easily observe
current waveforms while current continues to flow through the conductor being
measured.
●Three current measurement ranges: 0.1 V/A, 1 V/A, and 10 V/A.
●You can observe low-current waveforms at the high sensitivity of 10 V/A.
●LED warnings indicate overload and unlocked sensor head.
●Broadband frequency characteristics DC to 120 MHz.
●Demagnetization and automatic zero adjustment functions make it easy to get
ready for measurement.
2.3 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.
Unpacking and checking

Product description
R&S®RT-ZC31
10User Manual 1801.4949.02 ─ 03
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
2.4 Description of the Probe
2.4.1 Probe Overview
Figure 2-1: Probe overview
1 = Sensor
2 = Junction box
3 = Termination unit
Description of the Probe

Product description
R&S®RT-ZC31
11User Manual 1801.4949.02 ─ 03
2.4.2 Termination Unit
Figure 2-2: Termination unit overview
1 = Output terminal
2 = Unlock lever
3 = Ventilation holes
Description of the Probe

Product description
R&S®RT-ZC31
12User Manual 1801.4949.02 ─ 03
4 = Serial number
5 = Power plug
6 = Shell
Unlock lever
The lock mechanism keeps the clamp closed.
Vents
The vents are on the sides and bottom. Do not clog them.
Power plug
Connect the plug to the R&S RT-ZA13 probe power supply receptacle to supply
power to the sensor.
Shell
Pull on the power plug while simultaneously pulling this shell to disconnect the
plug.
Description of the Probe

Product description
R&S®RT-ZC31
13User Manual 1801.4949.02 ─ 03
2.4.3 Junction Box (Keys, LEDs)
1 = POWER LED
2 = OVERLOAD LED
3 = JAW UNLOCKED LED
4 = DEMAG/AUTO ZERO LED
5 = DEMAG/AUTO ZERO key
6 = RANGE LEDs
7 = ▲(Higher range) key
8 = ▼(Lower range) key
POWER LED
The POWER LED turns green (lighting up continuously) when the device is ener-
gized. It flashes rapidly if a checksum error has occurred.
Description of the Probe

Product description
R&S®RT-ZC31
14User Manual 1801.4949.02 ─ 03
OVERLOAD LED (red light)
Shows the overload status of the system. The following states are defined:
Color State
Flashes three
times
Indicates that demagnetizing or automatic zero adjustment cannot be per-
formed.
Fast flashing red Indicates that an overload state is detected, the device has entered pro-
tection mode or a checksum error has occurred.
JAW UNLOCKED LED (red light)
The JAW UNLOCKED LED turns red (lighting up continuously) if the sensor head
is not locked.
Color State
Lights red The upper jaw is unlocked.
Flashes three
times
Indicates that demagnetizing or automatic zero adjustment cannot be per-
formed.
Fast flashing red Indicates that the device has entered protection mode or a checksum
error has occurred.
DEMAG / AUTO ZERO LED (orange light)
Color State
Flashes slowly Demagnetization or automatic zero adjustment has not yet been per-
formed
Lights orange Demagnetization and automatic zeroadjustment are in execution
No light Demagnetization and automatic zero adjustment has been completed
Lights red The upper jaw is unlocked.
Flashes three
times
Indicates that demagnetizing or automatic zero adjustment cannot be per-
formed.
Fast flashing Indicates that the device has entered protection mode or a checksum
error has occurred.
DEMAG/AUTO ZERO key
Performs demagnetization and zero adjustment.
Press this key long (approx. 1 sec.) for demagnetization and zero adjustment.
Press this key short (within 0.5 sec.) for a zero adjustment only.
Demagnetization and zero adjustment cannot be performed in the following cir-
cumstances:
Description of the Probe

Product description
R&S®RT-ZC31
15User Manual 1801.4949.02 ─ 03
●The sensor head is unlocked (JAW UNLOCKED LED is lit up)
●During an overload condition (the OVERLOAD LED is flashing)
●When a measured current is detected
(Higher range) key / (Lower range) key
Switch over to a next higher / lower current range.
RANGE LEDs (green lights)
Color State
Lights green The current range is chosen.
Fast flashing Indicates that the device has entered protection mode or a checksum
error has occurred.
2.4.4 Sensor
Description of the Probe

Product description
R&S®RT-ZC31
16User Manual 1801.4949.02 ─ 03
1 = JAW UNLOCKED indicator
2 = Current direction indicator
3 = Opening lever
4 = Sensor aperture
5 = Jaws
6 = Sensor head
JAW UNLOCKED indication
If the sensor head is unlocked, you can see this indication on the probe.
Current direction indication
Clamp the device to the conductor so that the direction in which the current being
measured is flowing matches the arrow.
Opening lever
Operating lever for opening the sensor head. Always use this lever to open the
sensor head.
Sensor aperture
A conductor to be measured has to pass through this aperture.
Sensor head
The sensor head clamps on the conductor being measured, and carries out the
actual current measurement.
Description of the Probe

Connecting the probe
R&S®RT-ZC31
17User Manual 1801.4949.02 ─ 03
3 Connecting the probe
3.1 Handling the probe
The R&S RT-ZC31 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.
●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.
●Do not obstruct the ventilation holes on the sides and bottom of the terminator,
as it could overheat and be damaged, or cause a fire.
●Do not store or use the device near induction heating systems (such as high-
frequency induction heating systems and IH cooking equipment)
●Do not store or use the device near HF power supply units.
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.
– Do not place foreign objects between the mating faces of the sensor head,
insert foreign objects into the gaps of the sensor head, or touch the mating
faces.
– 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.
Handling the probe

Connecting the probe
R&S®RT-ZC31
18User Manual 1801.4949.02 ─ 03
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".
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 power supply
1. Have the R&S RT-ZA13 probe power supply, and an oscilloscope or waveform
measuring instrument ready.
2. NOTICE! Voltage check. When using a different power supply than the
R&S RT-ZA13 probe power supply, before turning on the power, make sure
that the voltage of the used power supply matches the supply voltage indica-
ted in the data sheet "R&S RT-Zxx high voltage and current probes".
Turn off the power switch at the rear of the R&S RT-ZA13 probe power supply.
3. Connect the power cord.
4. Connect the power plug of the R&S RT-ZC31 to the power receptacle of the
R&S RT-ZA13 probe power supply.
5. Check that the conductor being measured is not clamped when supplying
power to the R&S RT-ZC31. When power is turned on, a demagnetizing wave-
form is initially applied to the output. This is intentional in the design, and not a
fault.
Connecting the probe to the power supply

Connecting the probe
R&S®RT-ZC31
19User Manual 1801.4949.02 ─ 03
6. Turn on the power switch of R&S RT-ZA13 probe power supply. Ensure that
the front panel power indicator lights.
The POWER LED lights up in green and the DEMAG/AUTO ZERO LED is
slowly flashing in orange.
7. Connect the R&S RT-ZC31 to the oscilloscope, as described in Chapter 3.3,
"Connecting the probe to the oscilloscope", on page 19.
3.3 Connecting the probe to the oscilloscope
●The output of this device is terminated internally. Use a high impedance
input of the measuring instrument. With an input impedance of 50 Ω,
accurate measurement is not possible.
●If using BNC-banana plug adapters or similar to connect to input termi-
nals other than BNC connectors, make sure the polarity is correct.
To connect the probe:
1. NOTICE! Risk of instrument damage. To avoid damaging the terminator, keep
it oriented in a straight line relative to the waveform measurement instrument
when connecting and disconnecting it.
Insert the terminator of the R&S RT-ZC31 straight into one of the BNC input
connectors of the oscilloscope until it clicks. Take care not to tilt it.
Figure 3-1: Connecting the probe to the Rohde & Schwarz oscilloscope
2. Configure the probe connection at the oscilloscope.
Connecting the probe to the oscilloscope

Connecting the probe
R&S®RT-ZC31
20User Manual 1801.4949.02 ─ 03
The exact procedure depends on the used instrument and is described in the
oscilloscope's user manual. Supported oscilloscopes are listed in the R&S RT-
Zxx data sheet.
Make sure to set the following:
● Vertical unit = Ampere
● Coupling = DC
● Termination = 1 MΩ
● Manual Gain = 0.1 V/A, 1 V/A or 10 V/A
Alternatively, select "Predefined probe" = R&S RT-ZC31 (0.1 V/A)/(1 V/A) /(10
V/A) if this selection is available on the instrument.
To disconnect the probe:
1. To avoid damaging the output connector of the terminator, or the BNC input
terminal’s locking mechanism on the oscilloscope, do not rotate when both ter-
minals are connected.
2. Pull the unlock lever toward you.
3. Pull the connector away from the oscilloscope.
3.4 Setting up and demagnetizing
During demagnetization (DEMAG / AUTO ZERO LED lit), the device outputs a
demagnetization waveform (which attenuates over time) from its output terminal.
This waveform, which appears on a waveform measuring instrument, may be
asymmetric along the horizontal axis. However, this does not represent a device
malfunction.
Setting up and demagnetizing