High Resolution Wheel Pulse Transducer

The Michigan Scientific (MSC) High Resolution Wheel Pulse Transducer (WPT) uses an integrated encoder, which is attached to a customer’s wheel using MSC wheel mounting components. It is commonly used for automotive testing and gathering data on wheel speed, vehicle speed, and distance traveled.


  • Easy Installation
  • Encoder wheel speed sensor
  • Up to 1024 ppr
  • Available with or without weatherproof seals
  • Circular connectors on stator and rotor
  • Sealed, corrosion resistant metal housing
  • Lightweight and compact
  • NIST traceable calibration
  • Used in
    • Speed Testing
    • Vehicle Brake Testing
    • Distance Measurement
    • Map Validation


The High Resolution Wheel Pulse Transducer Assembly is used as rotation sensor mounted outboard of a vehicle wheel. The rotation sensor is used to measure rotational velocity, angular position, and direction of rotation. The assembly consists of electronics in a rugged housing, which is attached to a wheel plate and mounted on the customer wheel using collet lug extensions. The output signals generated by the sensor can be use to determine wheel speed, acceleration, distance, and vehicle speed.

The WPT is very rugged and has been designed to accept contacting rotary seals. Units ordered with these seals are weatherproof with an IP67 rating. For higher speeds in dry conditions, order units without the contacting rotary seals.


Like many of Michigan Scientific’s products, the High Resolution Wheel Pulse Transducer instrumentation package is designed to be used on a variety of vehicles in many different testing applications. It is the optimal tool for  determining how far a vehicle has traveled, how fast the vehicle or wheels are going, and how fast the vehicle is accelerating. The output signals from the WPT are used for analysis in acceleration and braking tests as well as ABS testing. This is crucial when determining the tractive contact a vehicle has with a surface during vehicle development. These systems are commonly used during autonomous and electric vehicle development and weather testing in standard customer vehicles. Having an accurate measurement of wheel speed and distance traveled is also important for mapping for vehicle GPS and navigation systems. Wheel Pulse Transducers provide reliable measurements to aid in vehicle innovation.

Encoder Options

Rotation sensor choices E256, E360, E500, & E512:
Four optical encoder resolutions are offered, see the table below. Each of these encoder choices have four outputs, shown graphically below. Outputs A and B are in quadrature, meaning they are 90° out of phase. Output I is an index pulse. Output A+B is the exclusive OR of A and B, which doubles the basic resolution of the encoder. The outputs, 0 to 5 volt pulses, can drive TTL loads. The encoders have metal code wheels and rugged electronics, which are designed to tolerate shock and vibration.

See “Signal Conditioning Hardware” tab for more options.

Signal Conditioning Hardware

Michigan Scientific Corporation also manufacturers encoder signal conditioners, which can be used to convert the digital pulses of the WPT sensor encoder to other signal formats. The EC-LV and EC-SC are small enclosures that can be added in-line with the stator cable and do not require any additional programming. The EC-LV converts digital pulses to linear voltages and the EC-SC converts digital pulses to digital sine and cosine waves.

EC-LV Linear Voltage Conditioner

The EC-LV conditioner converts 0-5 V digital pulses to linear voltages proportional to angular position and angular velocity. The external switches allow the user to select the speed range and direction of rotation. It outputs angular position and velocity signals, in addition to the four encoder signals.


EC-SC Sine-Cosine Conditioner

The EC-SC conditioner converts 0-5 V digital pulses to digital sine and cosine waves. The sine and cosine waves are 90° out of phase and one complete cycle is equivalent to one revolution of the vehicle wheel. The output voltages are 10 V peak-to-peak. The EC-SC has an external switch to select the direction of rotation.