Vibrating Wire Sensor

Good Afternoon,

I'm looking for some advice with trying to interface a vibrating wire sensor to the Arduino.

The sensor is used to measure strain, it is mounted to a surface and then a electromagnet inside the sensor is excited. This causes an attraction to a thin wire within the unit. When the excitation is released the wire is supposed to vibrate at its resonant frequency (which changes with strain).

Sensor: http://www.geosense.co.uk/media/ProductDatasheet/16/file/VWStrainGaugeSurfaceMountVWS2000V1.1.pdf

The returned wave comes down the same set of wires which are used to excite the sensor and I am having trouble trying to measure the frequency! I have tried to use a H bridge type arrangement so that I can disconnect the sensor from the Arduino outputs but I still don't see any values returned. I have the sensor connected to a op amp configured with a 2.5v ref to allow for positive and negative swings.

I can hear the sensor activating, and can produce a tone with it if supplied with a sweep of frequencies.

Any help would be greatly received.

Thanks,

make that amp derive to give out a digital signal. measure pulse frequency

You will need to provide quite a bit more information before you can expect much help. At the very least you should post a schematic diagram showing how you are attempting to excite the coil and measure the resulting signal. Also post code, using code tags ("#" button).