We can directly attach the sensor to track, or any other ways.

-- Youda

On Mon, Aug 17, 2009 at 3:27 PM, Carl Denk <cdenk@windstream.net> wrote:

> That sounds similar to a defect detector, that is widely used in the
> USA. It counts axles, scans for hot bearings, and other defects. How
> close to the rail will this be located? Can you mechanically fasten it
> to the rail? If so an accelerometer.
>
> Youda He wrote:
> > I need to find some audio frequency sensor for an application.
> > The sensor will be placed on railroad track to "listen" the sound from
> > train, in order to warn people the train is approaching. I also want to
> > check if the sensor can tell whether the track has problems, such as
> > fracture, assuming I also had a signal generator at certain distance on
> the
> > track, produce a impulse or other signal (like hitting the track using a
> > hammer), by receiving the signal, I can do power spectrum analysis to
> find
> > out if there are fractures on the track.
> >
> > Any idea on what type of sensor are available there?
> >
> > -- Youda
> >
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