The CW-401 is a current clamp meter for amperages up to ±30 A. The device consists of a base unit and a separate sensor head, interconnected through a flexible hose. The housing has very small dimensions and is still very robust, which makes the CW-401 ideal for measurements in rugged environments and hard-to-reach places. 

Even at high ambient temperatures up to +120 °C, the CW-401 has outstanding accuracy due to an intelligent compensation algorithm and its digital signal processing with an microprocessor.

Current measurements are transmitted as digital values over a CAN bus. Through this bus system typically used in automotive applications, measurements can be sent over long lines without any degradation due to EMI or noise.

In combinationen with the CW-140, the CW-401 can be used as mobile current measurement device. Measurement values and other informations can be displayed on the touchdisplay of the CW-140


  • Measurement ranges: ±10 A or ±30 A
  • Accuracy 1 % at higher currents or ±50 mA
  • output of measuring rates over CAN-bus
  • Extensive microprocessor-based calibration
  • Temperature range: -20 °C to +110 °C (-40 °C to 120 °C optional)
  • Rugged aluminium housing
  • Small form factor, swivelling sensor head, suitable for hard-to-reach places
  • Factory calibration

Current measurement

Measurement range: Version for ±10 A and ±30 A 
Sampling rate: 1 kHz
Resolution: 1 mA
Accuracy: 0 A - 5 A: ±50 mA
5 A - 30 A: ±1 % of reading 
Signal frequency: max. 250 Hz


Number: 1
Type: ISO 11898-2 (highspeed)
CAN protocol versions 2.0 A and 2.0 B, supports  SAE J1939 (29-bit-identifer) 
Bit rate: Highspeed up to 1 Mbit/s
Termination: -
Output rate: max. 500 Hz, software configurable 
Connector: D-Sub socket 9-pin, further on request

power supply

Supply voltage: 9 VDC to 30 VDC
Current consumption: 40 mA at 12 VDC

Environmental conditions

Temperature range: -20 °C to +110 °C
Temperature range extended (optional): -40 °C to +120 °C
Protection class: IP 65

General information

Housing: Rugged aluminum case
Dimensions sensor head (LxWxH): 40 mm x 26 mm x 13 mm
Dimensions base unit (LxWxH): 48 mm x 32 mm x 13 mm
Dimensions connecting hose: Ø 8 mm x 55 mm, min. bending radius 20 mm 
Weight: 80 g
Calibration: Factory calibration, DAkkS calibration on request
  • Offset-Calibration over CAN-Bus
  • Automatic remanence correction
  • Integrated temperature measurement
  • Output of measuring rates over CAN-Bus


Datasheet CW-401

Download (PDF)

Back to the overview | CW-400 Series