RS425 Contactless Torque Transducer

These contactless Torque Transducers are not limited by operational speeds, can fit any shaft and capable of measuring torque from 1Nm and up to 500kNm, providing highly accurate and reliable torque measurement in many applications.

Contactless Torque Transducer with a completely separate rotor and stator

RS425 1000Nm Torque Transducer | Torque Sensor | RS425 Contactless Torque Transducers | RS425 1000Nm Torque Transducer|RS425 1000Nm Torque Sensor | Torque Transducers|RS425 1000Nm Torque Transducer 2

The Datum Electronics Series RS425 contactless torque transducer has been designed to fit easily in line with any drive-train or test rig, using either a spline or key-way shaft. This type of torque sensor has many advantages over other torque measurement systems, including zero bearing friction, high speed and high torque applications.

The Series 425 Contactless Torque Transducers can be adapted to replace existing drive shafts on test rigs and in drive lines, saving the time and cost of designing in special couplings and intermediate shafts to accommodate conventional torque transducers. We are able to modify the ends of the transducer to best suit your requirements, and can even design bespoke ends to fit. By measuring torque on longer drive shaft, you prove the accuracy of the measurement and its tolerance to offset loads. Using a direct replacement with a lightweight rotor the dynamics of the driveline are maintained.

RS425 Rotary Torque Transducer

The RS425 rotary bearingless torque transducer utilises a strain gauged shaft for accurate and reliable torque measurement and a set of rotating on shaft conditioning electronics, where the digital signals are transmitted to the non-rotating part of the system or stator providing a reliable and highly accurate torque measurement solution. The rotor is continuously powered, enabling static and rotary torque measurement to be made. Not only does the RS425 Series offer great technical advantages, but this range of contactless torque sensors are also competitively priced.



Non Contact Torque Transducers and Torque Sensors


 RS425 Rotary Torque Transducer Specifications

RS425 TORQUE SENSORSSize 1Size 2Size 3Size 4
TORQUE RANGE0-100Nm0-500Nm0-2,000Nm0-10,000Nm
Keyway or Spline Shaft


Various SCADA Outputs, including RS485 as standard
DIGITAL: USB, Ethernet, RS485/232 and USB memory logging
ANALOGUE: 3 Channels of Torque, Speed and Power as 0-10V/4-20mA
Strain gauge signal, digital on-shaft
with inductive loop
OUTPUT DATA1-4000sps

*In many cases higher RPM ratings can be attained, please call our engineering team to discuss your applications.

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The RS425 Contactless Torque Sensor Range

The RS425 series contactless torque transducer is not limited by bearings; therefore it can be used at higher speeds and places with no bearing loads on to the shaft. The stator needs to be mounted in relation to the shaft within an operating envelope of +/- 3 to 5mm.

The standard range can measure torque ranges from 0Nm up to 10kNm,  bespoke torque transducers (where the same modular elements have been applied)  are also available, from as low as 1Nm and up to 500kNm.

Using our new generation of electronics as found in our industry standard M425 Torque transducer, the RS425 gives customers the ability to choose the sample rate that they need from 1 up to 4000sps, with higher resolution using up to 24bit technology.

The Competitive Edge

The Series RS425 contactless torque transducer transmits calibrated digital data as this is a cleaner and more defined method of transmitting data. The on-shaft signal from the strain gauge is converted to a digital signal and amplified on a shaft. It is this signal, that is taken off the shaft and processed by either with our DUI; Datum Universal Interface, or with our free of charge GUI software, providing the end user with clean and definitive data transmission.

Contactless Torque Sensor with a Rotary Shaft and Static Body

Torque Sensor Instrumentation

The Series RS425 contactless torque transducer is compatible with our Datum Universal Interface (DUI), which gives a range of digital and analogue outputs, as well as a digital display of the torque, speed, and power. It can also be set in a legacy mode to work with our older range of indicators and displays.

If you require analogue signal, our Series 425 bearingless torque transducers are able to provide either 4-20mA or 0-10VDC output with DUI; by converting the digital data signal from the torque transducer to an analogue signal. However, the effect of external or electrical noise can depend on signal strength and definition. Other commercial applications may use slip rings or analogue signals to transmit data, but the outputs of the Datum Electronics series 425 torque sensors are digital as standard.

A popular option is to view data from the transducer on a PC or laptop for torque data analysis. Our DUI software has been developed to allow the user view the torque data in real time with optional data analysis for performance monitoring and control. Using a simple USB interface or Ethernet connection, the torque transducer data can be displayed and logged at the touch of a button with  DUI.

RS425 Contactless Torque Sensor with Digital and Analogue Outputs


If your requirements dictate anything above our standard torque sensor range of 10,000Nm, we can and have engineered torque measurement transducers up to 500,000Nm.

Contact Team





      RS425 Rotary Torque Transducer Datasheet
      RS425 Bearingless Torque Transducer User Guide

      RS425 Rotary Torque Senor Measurement Range

      Torque Sensor SizeRated Load
      Rated Load
      (lb ft)
      Speed (RPM)*
      Shaft Length Face to FaceBody WidthShaft
      Dia. g6 TOL (ISO 286-2)
      Keyway Length (BS4235-1 :1972)Keyway dth (BS4235-1 :1972)Output Module LengthOutput Module WidthKeyway Depth Off Axial Centre
      (BS 4235-1:1972)
      Overall HeightBase Fixing holes. Centre to centre
      Size 1 – A 0-100-100-10,000150501522.551128.54.3140120
      Size 1 – B0-200-200-10,000150501522.551128.54.3140120
      Size 1 – C 0-500-500-10,000150501522.551128.54.3140120
      Size 1 – D 0-1000-750-10,000150501522.551128.54.3140120
      Size 2 – A0-2500-2000-10,00017050304481128.511140120
      Size 2 – B0-5000-4000-10,00017050304481128.511140120
      Size 3 – A0-1,0000-7500-6,000240505078.5121128.520140120
      Size 3 – B0-2,0000-1,5000-6,000240505078.5121128.520140120
      Size 4 – A0-5,0000-4,0000-5,000240507578.5201128.530140120
      Size 4 – B0-10,0000-8,0000-5,000240507578.5201128.530140120
      Size 5 – A0-15,0000-12,0000-2,00029260110116321128.544220200
      Size 5 – B0-20,0000-15,0000-2,00029260110116321128.544220200
      Size 5 – C0-25,0000-20,0000-2,00029260110116321128.544220200
      Size 5 – D0-30,0000-25,0000-2,00029260110116321128.544220200

      *Higher speed requirements are available, please contact our team to find out more.
      *For more information please refer to the M425 Rotary Torque Sensor Datasheet and Handbook in the Technical Documentation section.



      • Datum HQ Headquarters
      • Castle Street
      • East Cowes
      • United Kingdom
      • PO32 6EZ
      • +44 (0) 1983 28 28 34


      RS425 Rotary Torque Transducer Datasheet
      RS425 Bearingless Torque Transducer User Guide


      • Lightweight Torque transducer
      • Completely separate rotor and stator set
      • Long-term operation reduced maintenance
      • Ideal keyway shaft for easy fitting
      • Spline shafts are available as an alternative
      • Ideal for high-speed applications
      • Standard range available from 0Nm-10,000Nm
      • Analogue Output available
      • Compatible with LABVIEW software
      • Ideal for fully sealed or underwater applications (IP 68)
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