CWT Ultra mini current probe, high frequency wideband, rogowski coil

CWT Ultra miniature wideband current probe
for ac current measurement

Powertek
UK Tel: +44 1788 519911
US Tel: +1 631 744 0294
Email : info@powertekuk.com

The CWT ULTRA Miniature current probes utilize a Rogowski Coil sensor thin enough (typical cross section 1.7mm) to fit between the legs of a T0220 semiconductor switching device. With a high frequency bandwidth up to 20MHz, the CWT ULTRA miniature is ideal for measuring steady state current, switching transients or pulsed currents between 300mA and 6000Apk in power electronic equipment. The CWT ULTRA miniature probe is a clip around flexible coil current probe, based on the Rogowski principle to achieve high bandwidth measurement and faithful conversion of current to voltage, intended for use with oscilloscopes, transient recorders, data loggers, power meters and power analyzers. All models are supplied with an 80mm length clip-around coil, ensuring easy current monitoring even where access is limited.

cwtultra.jpeg (7485 bytes)

Sense coil thickness 1.7mm

1.7mm dia sense coils will fit between the legs of T0220 package
Very thin & flexible clip-around sense coil
Peak Current ratings from 30Apk to 6000Apk
Sensitivity set to give ± 6 volts peak output
(e.g. 20.0mV/A for ± 300A peak)
Capability of driving 50 ohm impedance
High Frequency Bandwidths 10Hz to 20MHz
Accuracy typically 0.2% of reading
Sense coil length of 80mm
Peak voltage isolation 1.2kV

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Ultra mini current sense coil and ferrule dimensions

Models and current ranges

	CWT015 200mV/A 30Amax 116Hz to 20MHz	order code CWT015 B / 1 / 80UM
	CWT03 100mV/A 60Amax 66Hz to 20MHz	order code CWT03 B / 1 / 80UM
	CWT06 50mV/A 120Amax 32Hz to 20MHz	order code CWT06 B / 1 / 80UM
	CWT1 20mV/A 300Amax 9.0Hz to 20MHz	order code CWT1 B / 1 / 80UM
	CWT3 10mV/A 600Amax 6.2Hz to 20MHz	order code CWT3 B / 1 / 80UM
	CWT6 5mV/A 1200Amax 3.2Hz to 20MHz	order code CWT6 B / 1 / 80UM
	CWT15 2mV/A 3000Amax 3.2Hz to 20MHz	order code CWT15 B / 1 / 80UM <<New>>
	CWT30 1mV/A 6000Amax 3.2Hz to 20MHz	order code CWT30 B / 1 / 80UM <<New>>
Cable length - The cable connecting the measurement coil to the integrator box is 1m

CWT Ultra mini data sheet PDF
CWT Ultra Mini user manual

CWT Ultra Mini specifications
Type	Sensitivity (mV/A)	Peak current (A)	Peak di/dt (kA/uS)	Noise max^*1 (mV_pk-pk)	Droop typ. (%/ us)	LF (3dB) bandwidth typ. (Hz) f_L	Phase lead at 1kHz typ. (deg)	HF (3dB) bandwidth typ. (MHz) f_H *²
Type	Sensitivity (mV/A)	Peak current (A)	Peak di/dt (kA/uS)	Noise max^*1 (mV_pk-pk)	Droop typ. (%/ us)	LF (3dB) bandwidth typ. (Hz) f_L	Phase lead at 1kHz typ. (deg)	^{Coil Length 80mm}
High Sensitivity Ranges of CWT .... measuring currents from 300mA
CWT015	200.0	30	1.0	20	0.100	116	8.4	20
CWT03	100.0	60	2.0	15	0.060	66.5	4.2	20
CWT06	50.0	120	4.0	12	0.030	32	2.1	20
CWT1	20.0	300	10.0	10	0.009	9.0	0.7	20
CWT3	10.0	600	20.0	10	0.006	6.2	0.7	20
CWT6	5.0	1200	40.0	10	0.004	3.2	0.7	20
CWT15	2.0	3000	40.0	10	0.004	1.5	0.7	20
CWT30	1.0	6000	40.0	10	0.004	1.5	0.7	20

^*1. Distributed around the f_L (3dB) bandwidth.
^*2. The high frequency bandwidth is in part dependent on coil length. Contact Powertek for values of f_H for other coil lengths.

TYPICAL ACCURACY (full scale)	Calibrated to UKAS ±0.2% with conductor central in the loop Variation with conductor position in the coil loop typically ±2%
TYPICAL LINEARITY	±0.05% (full scale)
ABSOLUTE MAXIMUM VALUES OF di / dt (kA/µs) (value must not be exceeded)	CWT 015, 03 CWT 06, 1 CWT3, 6	PEAK 25.0 PEAK 25.0 PEAK 40.0	RMS 1.0 @ 70^oC RMS 2.0 @ 70^oC RMS 2.2 @ 70^oC

Coil and cable
COIL CIRCUMFERENCE ‘A’ (mm)	80mm
COIL CROSS SECTION ‘B’ (mm)	1.7mm
PEAK COIL VOLTAGE ISOLATION (kV)	1200V
Safe peak working voltage to earth. Coils are flash tested at 3kV/60Hz for 60 seconds. Information about the continuous use of coils at high voltage can be obtained from Powertek
TEMPERATURE RANGE (^oC)	-10^oC to 70 ^oC
For de-rating due to temperature cycling please consult Powertek
CABLE LENGTH (metres) (from box to coil)	1m

Power input - mechanical - environmental
POWER SUPPLY	All CWT Ultra Mini units are supplied with four AA batteries (typical life 90 hours) and a 12V-24Vdc input socket and a power adapters to power the CWT from 230Vac or 115Vac. Specify adapter type, 230Vac or 115 Vac
INTEGRATOR BOX DIMENSIONS (mm)	H =183mm, W = 93mm, D = 32mm
OUTPUT SOCKET	BNC (output impedance 50 ohms- unit supplied with 0.5m BNC-BNC coaxial cable)
MIN. OUTPUT LOADING	>100kohm (for rated accuracy). 50ohm will reduce the sensitivity to half its normal value (for driving long cables >10m)
TEMPERATURE RANGE (^oC)	0^oC to 40 ^oC

Ordering
Model / sensitivity CWT Ultra mini unit is supplied with bnc-bnc cable, 12-24Vdc input, 4 AA batteries, power adapter, user manual, calibration certificate and carry case.	Denotes battery	/	Cable length (m)	/	Coil circumference (mm)
CWT015	B	/	1	/	80UM