Our Sensor Interface Unit (SIU) generates the laser signal for the optical probes, collects the return optical signal from the probes, and converts the optical signal into an analog voltage signal.
Picture above: Sensor Interface Unit (SIU)
The SIU includes several components:
- Modules to control the probes. For blade tip clearance, each module contains one laser and two return signal channels. For blade tip timing, each module contains two lasers and two return signal channels. Each module can control one blade tip clearance probe or two blade tip timing probes. Up to 8 modules can be packaged into one SIU for controlling a total of 8 tip clearance probes or 16 tip timing probes. More channels are added by using several SIUs.
- A web interface to control the modules remotely: turn lasers on/off, adjust laser power, adjust gain, and more. This web server is typically controlled using the computer in the Data Capture Unit.
- Safety features: laser on/off key switch and laser interlock system.
Configured To Your Exact Needs
With its modular architecture, the SIU can be configured to your exact measurement needs. Eight modules can be inserted into each SIU and each module can be tailored to the customer test needs:
- For blade tip clearance measurement, each module is configured with 1 laser and 2 detectors.
- For blade tip timing (vibration monitoring), each module is configured with 2 lasers and 2 detectors. Note that a blade tip timing configuration can be used for blade tip clearance by not using one of the lasers.
Laser cards can be configured for 635nm red, 404nm blue, or infrared lasers. We offer lasers from 30 mW (which can be tuned down to eye safe level of <5mW at the probe tip) to 400 mW. Laser power is typically increased for use with long range probes or for hot sections of the turbine.
Connectors can be configured to be used with your preferred probes. FC, ST, and SMA connectors are used as standard connectors, and other connectors can be wired upon request.
The SIU is controlled through a web browser, typically from the data capture unit but the user can choose to control the SIU from another computer. There is no software to install. Connection is through an Ethernet cable.
Picture Above: Web Interface for the Sensor Interface Unit
16 analog voltage channels via BNC connectors. Our system supports coaxial cable lengths up to 100 m (300 ft).
Our Sensor Interface Unit was built with user safety in mind. Its redundant safety features are engineered to protect the operator:
- A physical key turns all lasers on and off. The operator working on installing or removing optical probes can take the key, ensuring that nobody will turn the lasers on.
- An interlock connection can be wired to a door, so that opening the door will turn the lasers off. This prevents accidental laser exposure by personnel entering the area. The interlock is an electrical switch which can be wired to any safety system designed by the user.
Manual gain selection and self-controlled auto gain control for easy optimization of output voltage range are available.
Our Sensor Interface Unit operates from 0 to 50 deg C (32 to 120 F) and can be positioned close to the turbomachinery under test.