PEM CWT Ultra Mini (CWT UM / CWT UM-S) AC Current Probe
The PEM AC Current Probes utilize a Rogowski Coil and Matched Analog Integrator to provide accurate non-contact, measurement of AC currents over a very broad frequency range. These flexible “clip-around” Current Probes have very low insertion impedance compared to Current Transformers, (CT), or Hall Current Transducers, are easy to insert in confined spaces and are not damaged by over-current surges. They can be used for measuring ac, pulse or transient current waveforms. Since the PEM Current Probes have no magnetic core they can be used to measure ac current on a conductor with high dc current or in the presence of a high dc magnetic field.
Standard CWT UM AC Current Probes have a 1.7mm cross section. CWT UM-S AC Current probes have a thinner cross section of 1.2mm.
Features
- Peak Current ratings from 30A to 6kA
- Robust, flexible, clip-around coils
- Integrator included with Rogowski Coil to provide an analog signal accurately proportional to primary current in amplitude and phase
- High voltage isolation and common mode rejection
- Measure ac current even in the presence of a high dc current
- Not influenced by high dc magnetic fields
- Bandwidth from 2Hz to 50MHz
- No I*t limitation as with CT
- Both battery (4xAA) and external DC power supply
- CE marked
- Special cryogenic versions
- Special long coil versions
Applications
- Monitoring current waveforms in semiconductor switches
- Development, test and servicing of power electronic equipment.
- Pulsed Power capacitor discharge and magnetic accelerator current measurements
- Welding, motor drive, generator, currents
- Ground currents in rotating machine shafts
- Induction heating and plasma current measurements
- Measuring AC currents in the presence of large DC currents
- Fault monitoring, circuit breaker interuption and lightening strike currents
- Monitor Battery and Capacitor Ripple Current
- Induction Heating Cooking Appliances
Tech Support
Instructions for Use
Mechanical Dimensions
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- CWT Application Notes
- CWT Technical Note – Delay and Rise Time
- CWT Technical Note – Low Frequency Performance
- Voltage Immunity
- Accurate Power Conversion Measurements on High Power Motor Drives
- Instructions for CWT Integrator Module Fuse Replacement
- CWT Ultra Mini Accuracy Notes
- CWT Ultra Mini Technical Note – High Frequency
- Temperature testing Ultra-mini Coil
- Application Note – CWT AC Current Probes – what is minimum recommended current?
- Application Note: Transducer Termination Impedance – Low and High Frequency Analysis
- PEM CWT AC Current Probes (Rogowski Coils) – Equivalents
- “High Performance Rogowski Current Transducers”, W. F. Ray and C. R. Hewson
- “Next-Generation Current Probes for High-Speed and High Power-Density Applications”, Dr Chris Hewson, Power Electronic Measurements Ltd
- “Power Integrity” by Steve Sandler. See Chapters 5: Probes and 7: Measuring Impedance for applications using PEM Rogowski Coils (purchase of book required).
- CWTUM Gain and Phase Error Charts
- Measuring Fast Switching Currents with CWT UM, CWT Mini and CWT MiniHF, Dr Chris Hewson, APEC 2015
Pricing
Product Configurator:
Select product options from drop-down menus to quote standard products not normally in stock. For fully custom products, fill in the message box below.
Order Code for CWT Ultra Mini: Type / Battery / Cable Length / Coil Circumference
For example: CWT UM/015/B/1/80
For descriptions of the possible selections, please see the Specifications above.
CWT Ultra Mini AC Current Probe
| Part No. | Description | Price | In Stock |
|---|---|---|---|
| CWT UM/015/B/1/80 | AC Current Probe, Ultra-mini, 200mV/A, 30A, 116Hz-30MHz, Alkalai battery 4xAA, 1m cable length from Coil to Integrator, 80mm Coil circumference length, 1.7mm cross section. Includes US13S power supply. | $1,200.00 | |
| CWT UM/03/B/1/80 | AC Current Probe, Ultra-mini,100mV/A, 60A, 67Hz-30MHz, Alkalai battery 4xAA, 1m cable length from Coil to Integrator, 80mm Coil circumference length, 1.7mm cross section. Includes US13S power supply. | $1,200.00 | |
| CWT UM/06/B/1/80 | AC Current Probe, Ultra-mini,50mV/A, 120A, 34Hz-30MHz, Alkalai battery 4xAA, 1m cable length from Coil to Integrator, 80mm Coil circumference length, 1.7mm cross section. Includes US13S power supply. | $1,200.00 | |
| CWT UM/1/B/1/80 | AC Current Probe, Ultra-mini, 20mV/A, 300A, 9.2Hz-30MHz, Alkalai battery 4xAA, 1m cable length from Coil to Integrator, 80mm Coil circumference length, 1.7mm cross section. Includes US13S power supply. | $1,200.00 | |
| CWT UM/3/B/1/80 | AC Current Probe, Ultra-mini, 10mV/A, 600A, 6.2Hz-30MHz, Alkalai battery 4xAA, 1m cable length from Coil to Integrator, 80mm Coil circumference length, 1.7mm cross section. Includes US13S power supply. | $1,200.00 | |
| CWT UM/6/B/1/80 | AC Current Probe, Ultra-mini, 5mV/A, 1.2kA, 3.2Hz-30MHz, Alkalai battery 4xAA, 1m cable length from Coil to Integrator, 80mm Coil circumference length, 1.7mm cross section. Includes US13S power supply. | $1,200.00 | |
| CWT UM/15/B/1/80 | AC Current Probe, Ultra-mini, 2mV/A, 3kA, 2.0Hz-30MHz, Alkalai battery 4xAA, 1m cable length from Coil to Integrator, 80mm Coil circumference length, 1.7mm cross section. Includes US13S power supply. | $1,200.00 | |
| CWT UM/30/B/1/80 | AC Current Probe, Ultra-mini, 1mV/A, 6kA, 2.0Hz-30MHz, Alkalai battery 4xAA, 1m cable length from Coil to Integrator, 80mm Coil circumference length, 1.7mm cross section. Includes US13S power supply. | $1,200.00 |
CWT Ultra Mini Accessories
| Part No. | Description | Price | In Stock |
|---|---|---|---|
| US13S | CWT UM Regulated Power Supply. 120VAC, 60Hz, 12V ±10%, 300mA, Barrel type: 1.3 x 3.5 x 10mm. Power disconnects battery when plugged into the integrator. | $40.00 | |
| EU13S | CWT UM Regulated Power Supply. 100V-220AC, 50/60Hz, 12V ±10%, 500mA, Barrel type: 1.3 x 3.5 x 10mm. Power disconnects battery when plugged into the integrator. European plug type. | $40.00 | |
| UK13S | CWT UM Regulated Power Supply. 100V-220AC, 50/60Hz, 12V ±10%, 500mA, Barrel type: 1.3 x 3.5 x 10mm. Power disconnects battery when plugged into the integrator. UK plug type. | $40.00 | |
| PowerCableYK13 | Yokogawa compatible power cord, 0.5m, supports all PEM units fitted with a 1.3mm DC power socket. | $70.00 |
Re-Calibration
Note: Calibration on new product is discounted 50%.
New PEM Rogowski Coils include a Manufacturer’s Calibration Certificate at no extra charge.
| Part No. | Description | Price | In Stock |
|---|---|---|---|
| OL-17025-500A-AC | 17025 Accredited Calibration, Current Transducer, Full-scale Range between 0 and 500Arms, 50-400Hz, https://gmw.com/quality/ | $300.00 | |
| OL-17025-500A-AC-ADD | Calibration of Additional Transducer | $150.00 | |
| OL-17025-2000A-AC | 17025 Accredited Calibration, Current Transducer, Full-scale Range between 501 and 2000Arms, 50-400Hz, https://gmw.com/quality/ | $400.00 | |
| OL-17025-2000A-AC-ADD | Calibration of Additional Transducer | $200.00 | |
| OL-17025-8000A-AC | 17025 Accredited Calibration, Current Transducer, Full-scale Range between 2001 and 8000Arms, 50-400Hz, https://gmw.com/quality/ | $500.00 | |
| OL-17025-8000A-AC-ADD | Calibration of Additional Transducer | $250.00 |
Repair
| Part No. | Description | Price | In Stock |
|---|---|---|---|
| RECOIL-CWT | Recoil (replace damaged coil) and Recalibrate
| $820.00 |
Terms and Conditions
Quantity Discount Schedule:
| Quantity | 1 – 9 | 10 – 24 |
| Discount | 0% | 5% |
Terms and Conditions:
Prices above are for domestic deliveries to Canada, USA and Mexico only.
Prices are expressed in U.S. Dollars, FCA San Carlos, California.
Prices are subject to change without notice.
Higher quantity and OEM discounts are available.
Payment:
Visa, MasterCard, Amex, Prepayment before shipment, or Net 30 days (subject to credit
acceptance).
Delivery:
Items in stock shipped next business day. All other items are 8-10 weeks.