DirectShear - Optical™ Control Unit

Optical Shear (OS) Series | OSU-1001-H2U (Half Width 2 Rack Units)


Product Description

The OSU-1001-H2U AC/DC Differential Optical Sensor Unit is an integrated fiber optic and electronic system that provides the ability to measure mean and fluctuating quantities of interest using a differential optical sensor, e.g., wall shear stress or pressure. The OSU provides a stable light source and fiber optics to transmit light to and from the sensor head as well as optoelectronics to convert the light reflected from the sensor head to a single analog voltage signal for output to a data acquisition system.

Two integrated rechargeable lithium ion batteries minimize noise due to EMI and provide up to 20 hours of continuous operation. The control unit makes use of transimpedance amplifiers and an instrumentation amplifier to enable measurement of both mean and dynamic components.

Sensor Options:

This control unit pairs with the following sensor.

Key Features

  • Mean and fluctuating optical sensor measurements compatible with all DirectShear CS Series models
  • Selectable low-noise AC or rechargeable Li-ion battery power source
  • Optimized high dynamic range and bandwidth
  • System status and battery voltage LED indicators
  • Rugged, industrial LC Duplex fiber connection
  • Removable shielded sensor cable


  • Time-resolved, direct mean and fluctuating wall shear stress measurements
  • Differential optical shear stress sensors for subsonic and transonic applications
  • Instrumentation-grade skin friction sensing
  • Aerodynamic drag research
  • Detection of flow separation
  • Wind tunnel instrumentation

What is the typical application for DirectShear Sensors?

DirectShear Sensors are typically used in wind tunnel testing applications. 

Does each sensor need its own control unit?

Yes. Each sensor requires a dedicated control unit and each unit supports a single sensor at a time; however, multiple sensors can be paired with a single control unit in cases where spares or different sensor types are desired. Engineering services are available for customers who desire custom configurations of control units to support multiple sensors.