Alan

 I am not sure about the legality of revealing a measurement system that
is copyrighted by the US government.  Are you sure you want to run the
risk of being put in prison or worse (being forced to use the spool
method of tank level mesurement)

Gus





Put a spool and line on a stepper motor.  On the end of the line have
a fishing weight and ping-pong ball, coating the weight in epoxy or
don't use lead if it's drinking water.  Pay out the line and it will
magically become lighter when it hits the water.  You could even put the

shaft in a bearing on a strain gague.  Know what the max weight is out
of water and min is with float supporting weight.  Have the motor wind
up and down to keep the strain about halfway in between and you have a
continuous readout.  Could maybe get by without the strain gague.
Microswitch on top and bottom and spring pulling up on shaft instead.
Weight out of water = switch on bottom closed.  Float all in supporting
weight = spring pulling up closes up switch.  Somewhere in between both
switches off and the float/weight will be riding water level.


--
Gus Calabrese    Lola Montes      WFT Electronics
4337 Raleigh Street      Denver, CO 80212
303 964-9670......voicemail      wft@frii.com   http://www.frii.com/~wft

EMERGENCY:   791 High Street     Estes Park, CO  80517
if no success with wft@frii.com, try .... wft@bigfoot.com   then
wft@eudoramail.com