Water tank level indicator.

[CDK]

Frosty, it took some time because the company I did business with in the far past had their name changed.

http://www.gentechsensors.com/products.asp

This is a UK supplier with a worldwide sales network. Good luck!

[dskira]

The wood stick. Never fail, no need of power accurate and cheap.
Serious.
cheers
Daniel

[hoytedow]

Originally Posted by dskira

The wood stick. Never fail, no need of power accurate and cheap.
Serious.
cheers
Daniel

This is the same technique used by gas stations. Works every time.

Originally Posted by hoytedow

This is the same technique used by gas stations. Works every time.

Does´nt it give a bad taste to the water when you use the same stick?

[hoytedow]

Funny.

[Submarine Tom]

And it doesn't have to be a wooden stick.

If it's awkward to get at use a bendable strip of plastic or whatever.

Another hole can even be made and an engine dip-stick style device can be

used. You may choose to sanitise it before, after or during use to avoid

infecting the tank.

-Tom

[Frosty]

All very helpful but totally unsuitable.

What I was hoping for was a electronics expert draw a circuit of the electronics required to measure the depth of water by the 2 wire method measuring resistance corresponding to the depth in the tank.

I already have this on STBD tank but the port tank has now been replaced twice. My thoughts are that there would not be much in them and one could be made.

[CDK]

That's correct Frosty. Just two parallel wires, a low power AC source and a current measuring circuit. It can also be done with DC, but in that case the wires must be inert, like gold, tungsten etc.

[Frosty]

CDK so what do I buy to make one. the innards of the old one will not be removable as it is epoxied in. I would smash this out and rebuild the circuit in there. What do I need to build one?

[CDK]

Just one LM3914 bar graph driver and 10 small LEDs, a few resistors.
The datasheet (http://www.national.com/ds/LM/LM3914.pdf) shows several examples.
The wires should be straight and parallel. Stainless steel will survive several years if the current is kept low.