You may also like…
DirectShear – Optical | Control Unit
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.
|Control Unit Form Factor||
- 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
- Direct measurement of shear stress
- Harsh environment capable
- Non-intrusive - minimal flow disturbance
- High resolution, dynamic range and bandwidth
- Immune to EMI
|Model||Shear Stress (Pa)||Bandwidth (kHz)||Sensitivity (mV/Pa)||Resolution (mPa)||Element Size
|OS-0510||10||0.8||190||0.1||1.5mm x 0.7mm|
|OS-0110||50||1.8||40||0.5||1mm x 0.7mm|
|OS-0610||100||2.5||20||1||1mm x 1mm|
|OS-0210||300||5||5||2||0.4mm x 0.4mm|
|OS-0310||1000||10||1.3||50||0.3mm x 0.3mm|
|OS-0410||5000||20||0.3||50||0.3mm x 0.3mm|
The following additional components and specifications are recommended for AC and DC testing/calibration with the capacitive sensor control unit:
- RG58 coaxial cable with BNC connectors
- Data acquisition system (DAQ) – AC/DC measurement
- Sensing Range: ±1, ±5, ±10V – sensor dependent (see datasheet)
- Resolution: 18+ bits
- Sampling frequency:
- Sensor dependent w/ analog filter between sensor output and analog-to-digital converter (ADC)
- 100+ kS/s w/o analog filter
- Digital multimeter – DC measurement only
- 6.5 digits with power line cycle (PLC) integration
- DAQ or PC connection (e.g., GPIB)
Related Research Projects
Frequently Asked Questions
What is the typical application for DirectShear - Optical Sensors?
What are the operating temperature ranges for DirectShear - Optical sensors?
How do acceleration forces affect the sensor?
The sensor can survive large accelerations; more than 200g. The floating element’s small size and mass limit any significant inertial loads. However, accelerations will affect the output of the sensor. To account for acceleration, an additional accelerometer should be placed near the DirectShear sensor and subtract the coherent power between the DirectShear sensor and the accelerometer. IC2 provides the acceleration sensitivity data in the calibration packet included with each sensor purchase. IC2 is currently working on a future generation of the sensor that will compensate for acceleration automatically. Please contact IC2 for additional information regarding acceleration compensation.