Alberto Smulders wrote:
>
> Hi Rick !!!
>
> Another very interested person here, looking for a cheap method to measure
> contents in grain and oil storage bins - should be a kind of ultrasonic
> rangefinder, maximum range around 10...12 meters, ruggedized for use in an

I've often wondered if one can't use a speaker to see at which frequency
it resonates to measure the empty space in vessels like these. Another
application would be a pertol tank.

Has anyone tried this?

--
Friendly Regards

Tjaart van der Walt
mailto:tjaart@wasp.co.za
 _____________________________________________________________
| WASP International http://www.wasp.co.za/~tjaart/index.html |
|       R&D Engineer : GSM peripheral services development    |
|   Vehicle tracking | Telemetry systems | GSM data transfer  |
|    Voice : +27-(0)11-622-8686 | Fax : +27-(0)11-622-8973    |
|              WGS-84 : 26010.52'S 28006.19'E                 |
|_____________________________________________________________|