Fylde FE-596-CDT4 Electronics Module
For Blade Tip Clearance Measurement and Tip Timing Systems
Although our capacitive sensors are compatible with a number of commercially available electronic systems we recommend the use of Fylde FE-596-CDT4 electronic modules and associated equipment, as shown below:
The FE-596-CDT4 module is a 4 channel high speed capacitive displacement measurement system that senses the capacitance developed between the sensor electrode and passing blade tips as they rotate within the engine.
The system converts the measured capacitance change from the probe into a voltage output that increases as each blade tip approaches the sensor and then falls to a nominal zero baseline when there is no blade tip present.
This system output is called the blade passing signal (BPS) as and can be used to measure blade tip clearance as a function of the signal amplitude and also blade vibration by monitoring the time interval between the passing blades.
The system can generally be relied upon to give good fidelity on blade passing signals with passing times of less than 5μs. A typical output is shown below:
One of the main advantages of the FE-596-CDT4 module is the ability of the system to optimise itself for any probe and cable combination, with all system tuning and optimisation performed via an Ethernet connection or optionally via an RS232 interface.
System parameters such as gain, cable compensation, balance, AC coupling (including short term DC ability), are all under remote control.
For blade tip clearance measurements, sensor calibration is usually performed on a high speed spinning rig that simulates the actual blade tip profile to be measured and provides a calibration file of output voltage versus clearance.
The system can operate with a total combined input cable length of up to 25m and includes comprehensive reporting of the input cable electrical condition, together with automatic warning of any system overloads.
Our Japanese Distributor offers in-house calibration and system integration services together with system tutorials for new customers.