piclist 2001\10\02\081111a >
Thread: Cheap light level sensor
face BY : Tsvetan Usunov email (remove spam text)

>I'm still thinking about how to sense fuel levels in a fuel tank I'm
>building.  I'm leaning toward the idea of a clear shaft tapered at several
>lengths.  Can anyone suggest a cheap way of sensing the reflected light?
>The only cheap sensors I can find appear to have a sensing distance of only
>a few mm at best (I'd be using a ~12" shaft).  Am I looking at the wrong
>type of sensor for this purpose?

I would try two approaches:

1. ultrasonic distance measurement - put sender and received on the top of
your fuel tank. send chirps and listen the echo to calc the distance
2. capacitive (may be dangerous if not well isolated) - if your tank is with
metal walls (it should be if it's fuel tank) put well isolated metal rod
inside the tank and make high approx.200kHz frequency generator - the fuel
level will change the capacitance of your rod-tank wall system with 10 to
100 pf depend on your tank volume - then all you have to do is to measure
the frequency on the output

Best regards
PCB prototypes for $26 at http://run.to/pcb (http://www.olimex.com/pcb)
Development boards for PIC, AVR and MSP430  (http://www.olimex.com/dev)

http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email RemoveMElistservTakeThisOuTspammitvma.mit.edu with SET PICList DIGEST in the body

<000b01c14b43$288ce960$730524d4@ceco> 7bit

See also: www.piclist.com/techref/io/sensors.htm?key=sensor
Reply You must be a member of the piclist mailing list (not only a www.piclist.com member) to post to the piclist. This form requires JavaScript and a browser/email client that can handle form mailto: posts.
Subject (change) Cheap light level sensor

month overview.

new search...