[Shop-talk] Remote tank level sensing.

[Mark Miller]

Hi.  A friend asked me to come take a look when their water system 
failed recently.  Problem was easy to diagnose and fix (a leak caused 
the tanks to drain out faster than they filled up.  Leak fixed and the 
tanks refilled within a few days) and I [foolishly] offered to help set 
something up so it won't happen again as catastrophically.

The situation: there are some spring fed storage tanks about 50-100 feet 
away from the nearest source of power.  They typically remain full or 
nearly so and there is a system to keep them full (manual float valves). 
I would like to add some level sensors in the tank to indicate when the 
tank is less than 1/2-3/4 full (something might be awry) and another 
when the tank is almost empty to disable the (remote from the tanks, but 
located near power) booster pumps to prevent them from running dry and 
possibly overheating.

The most straightforward would be to put sensors in the tanks and run 
wires to relays at the pumps and indicators, but that would require 
trenching.  Anyone know of a good source for some battery operated 
transmitters and battery or wired receivers?  These are rather slow 
changing signals, so something that transmitted only at a change or had 
a transmit interval that could be set to a long time would be better for 
battery life (but changing batteries isn't that big a deal, just a pain).

Thank, o all knowing list!!

-- 
Regards,

Mark Miller
markmiller at threeboysfarm.com