CWTUMHF-F
Novel ‘forked’ Rogowski coil construction with excellent high frequency performance.
A wide-band AC current probe with a shielded version, an alternative coil configuration to measure current in dense power electronic circuits.
Product Synopsis
CWTUMHF-F
Novel ‘forked’ construction with a coil length of 55mm.
A wide-band AC current probe with BNC output to connect to most types of oscilloscope or data acquisition devices.
The CWTUMHF-F (1.7mm thickness) is the electrostatically screened version of the CWTUM-F and is an extension of the original CWT Ultra-mini range from PEM. The novel mechanical construction can reduce overall Rogowski coil size and thus the probes impact on the circuit under test. This simplifies measurements in densely populated power electronic circuits.
Features
- Novel ‘forked’ construction with a coil length of 55mm.
- Wide operating temperature -40°C to +125°C.
- Current ratings from 60A pk to 12kA pk.
- Coil insulation 1.2kV pk.
- Peak di/dt capability up to 100kA/μs.
- A shielded ‘HF’ version 1.7mm cross section diameter.
Excellent voltage immunity
HF (-3dB) 30MHz
Applications
- Switching current waveforms in power electronic circuits:
- MOSFET or IGBT devices as small as TO-220, D2PAK and other SMT power devices.
- Measuring power losses in semiconductor bond wires in power devices.
- Monitoring currents in small inductors, capacitors, snubber circuits, etc.
- Measuring small AC currents in the presence of large DC currents (e.g. monitoring capacitor ripple).
- Power converter development and diagnostics.
- Measuring high frequency sinusoidal, pulsed or transient currents in power frequency to rf applications.
Standards and Approvals
- CE marked
- Complies with EMC EN61326-1
- Complies with IEC 61010-1; IEC 61010-2-032
- PEM Ltd is certified to the ISO9001:2015 standard
PEM are committed to delivering the highest level of quality to our customers, read more about how we strive to achieve this in our Quality Standards and Compliance sections.
Key Features
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Novel ‘forked’ coil
Novel ‘forked’ construction with a coil length of 55mm.
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Wide operating temperature
Wide operating temperature -40°C to +125°C.
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Thin coils and high insulation
Coil insulation 1.2kV pk, a shielded ‘HF’ version of 1.7mm cross section diameter, and a thinner 1.3mm version.
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Peak di/dt
Peak di/dt capabilities up to 100kA/μs.
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Current ratings
Current ratings from 60A pk to 12kA pk.
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Customise cable length
Longer cables than the standard 1m are available on request.
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Custom coil length
Coil lengths longer than the standard 55mm are available.
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Bespoke options
Choose from a range of standard options or create a custom design.
Performance
CWTUMHF-F (Shielded / High frequency version - 1.7mm thickness)
| Model | Sensitivity (mV/A) | Peak Current (A) | Noise(mVp-p) | Droop (%/ms) | LF (-3dB) (Hz) | Peak di/dt (kA/μs) | HF (-3dB) Bandwidth
(MHz)
|
|---|---|---|---|---|---|---|---|
| CWTUMHF-F/03 | 100 | 60 | 20 | 85 | 150 | 4.0 | 30 (55) |
| CWTUMHF-F/06 | 50 | 120 | 15 | 78 | 100 | 8.0 | 30 (55) |
| CWTUMHF-F/1 | 20 | 300 | 15 | 53 | 50 | 20 | 30 (55) |
| CWTUMHF-F/2 | 10 | 600 | 15 | 19 | 20 | 40 | 30 (55) |
| CWTUMHF-F/6 | 5.0 | 1200 | 15 | 9.3 | 10 | 80 | 30 (55) |
| CWTUMHF-F/15 | 2.0 | 3000 | 12 | 4.6 | 5.0 | 100 | 30 (55) |
| CWTUMHF-F/30 | 1.0 | 6000 | 12 | 2.4 | 2.6 | 100 | 30 (55) |
| CWTUMHF-F/60 | 0.5 | 12,000 | 12 | 1.2 | 1.2 | 100 | 30 (55) |
Noise - ‘Noise’ is the internally generated integrator noise, this is predominantly the same frequency as the LF (-3dB) bandwidth.
HF(-3dB) Bandwidth - The HF(-3dB) is specified for a 1m cable and 55mm coil, we can supply longer coils and cables on request.
di/dt ratings
These are ‘Absolute maximum di/dt ratings’ and values must not be exceeded.
| Type | Abs. Max. peak di/dt | Abs. Max. rms di/dt |
|---|---|---|
| CWTUMHF-F | 100kA/μs | 1.0kA/μs |
Technical Specifications
CWTUMHF-F
- Output
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±6V pk corresponding to ‘Peak Current’ into ≥ 100kΩ (recommended e.g. DC1MΩ oscilloscope).
±2V pk, Sensitivity is half the nominal value into 50Ω. - Accuracy
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Calibrated to ±0.2% of reading with conductor central in the ‘Ideal conductor position’ area.
Conductor positional variation in the ‘Ideal conductor position’ area (for a 5mm dia. conductor) is typically ±1% of reading.
Linearity (with current magnitude) 0.05% of reading - DC offset
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±3mV max. at 25°C
- Temperature
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Coil and cable -40°C to +125°C
Integrator 0°C to +40°C - Coil voltage
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1.2kV pk
Safe peak working voltage to earth.
Rating established by a 3kV rms, 50Hz, 60 sec flash test. - Cable length
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1m (length of cable from coil to electronics).
(Longer cables are available on request). - Coil length
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55mm
(Longer coils are available on request). - Battery Options
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BAlkaline Batteries -- 4 x 1.5V AA alkaline batteries.
External power adaptor disconnects batteries and powers unit.RRechargeable Batteries -- 4 x 1.2V NiMH batteries.
External power adaptor trickle charges batteries and powers unit.External power adaptor available in US, EURO, UK & AUS versions as an optional extra.
Dimensions
CWTUM-F / CWTUMHF-F Dimensions
55mm Standard Coil Length
Novel ‘forked’ Rogowski coil construction
What is included?
The CWTUMHF-F is supplied with some standard items so your measurement is ready to go the moment you receive your probe.
Details of how to specify a CWTUMHF-F probe including peak current rating, coil circumference, cable length and the type of batteries to power the electronic integrator can be found in the performance section.
If you want to purchase a CWTUMHF-F you can get a quote, if your requirement is outside that listed on our website please contact us to discuss your requirements and application.
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CWT Probe
Clip-around Rogowski coil, with cable connected to an electronic integrator housed in a plastic enclosure. The enclosure has an output BNC socket, ON/OFF switch, slide panel for batteries and socket for external DC power.
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0.5m BNC Output Cable
Every CWT unit is supplied with a detachable 50ohm BNC to BNC output cable. (The CWTMini50HF output cable is fixed).
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Carry Case
Robust hard plastic carry case with handle to protect the CWT probe in transit. Dimensions: 330mm x 265mm x 58mm.
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Batteries
Choose from either (4 x 1.5V Alkaline) or (4 x 1.2V NiMH) Rechargeable AA Batteries. (The CWT has trickle charge capability for the NiMH battery option).
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Calibration Certificate
Every unit is supplied with a fully traceable calibration certificate.
Customise & Options
PEM can customise CWTUMHF-F current probes, and supply optional items, that may be required for your specific measurement.
Customisation can be as simple as choosing coil lengths or cable lengths outside those specified on the datasheet, or you may have more complex requirements, see custom designs for some examples.
Additional optional items for the CWT range include a low noise wall mount power adaptor.
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Longer Cables
Longer cables are available up to 2.5m.
(Custom lengths available on request) -
Longer Coils
Longer coils are available. Please Enquire.
(Custom lengths available on request) -
Power Adaptor
External power adaptor available in US, EURO, UK & AUS versions as an optional extra.
Get a Quote
Build your CWT product options and complete our online quotation form.
Custom Design
We can provide custom designs for one off applications or volume manufacture.
Downloads
For more information and documents please see our full technical resources area.
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Datasheets
XX21S and XX13S - Power Adaptor Technical Specification Datasheet PDF 575KB Updated: 20th November, 2024
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Datasheets
CWTUM-F / CWTUMHF-F Datasheet PDF 1.4MB Updated: 15th January, 2025
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Dimension Drawings
CWTUM-F / CWTUMHF-F Dimensions PDF 152KB Updated: 15th January, 2025
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Technical Notes
Voltage Immunity PDF 1.4MB Updated: 22nd October, 2024
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Technical Notes
Low Frequency Performance - 01A PDF 1.6MB Updated: 22nd October, 2024
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Compliance
CWT / LFR / CMC / DCFlex Warranty PDF 197KB Updated: 9th January, 2025
Technical Resources
Browse our extensive resources of technical information, insights and test data.
Get a Quote
Build your CWT product options and complete our online quotation form.
Applications
For more information on possible and suitable applications please review the applications below and click each one for further information.
There are currently no related applications to view. However, you can explore our full applications section.
Compliance
We prioritise compliance with industry standards ensuring all products are safe.
Quality Standards
We are committed to delivering the highest standards of excellence to customers.