Non-invasive water level gauges

muckypup

muckypup

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Is there such as thing as a non-invasive water tank level sender?

What I mean by this is that I have 2 stainless steel water tanks which don't have level gauges. All the senders so far require a hole cutting in the top. Problem is that to get the tanks out is very difficult (may even have to take the engines out).

I'm sure I remember someone posting something like this a long time ago. Can't find it though. I remember it simply sticking to the side of the tank...

Steve
 
Another method might be a flow meter on the tank output pipe which goes to a gadget that knows how much water the tank holds and can measure how much water is being used.

Anyone know a gadget like that?

Steve
 
Was hoping to find something that would hook up to a guage in the saloon or kitchen to save grubbing around in the engine bay just to check on how much water we have on board. We also have 2 100 gallon tanks, one on each side of the boat connected by a balance tube.

Steve
 
We use a Tank Tender. It does mean drilling a small hole in the top of the tank, but you can usually do it without removing the tanks, (so long as you can access a bit of the top of the tank!) The spill pipe that goes into the tank is flexible, so you don't need much access. They work very well, and our gauge is next to the galley and very convenient to read. They are available through Mailspeed and the web site is here. Fortunately it was fitted to the boat when we bought it, and I didn't have to pay the prices they are charging!
 
I have seen a unit that fixes on the outside of a gas bottle to tell you the level without having to put anything inside. I think the same can be done with water tanks.

Sight glasses are only any use if you can get access to the depth of the tank so not much use if the tank is in the bilge - it's fine with the tank on the bridge deck of my cat!

It is also possible to rig a manometer and a sqeezy bulb to measure the depth from hydrostatic pressure by blowing air down the outlet pipe.
 
Every house has a water meter to measure how much water you have to pay for. Its extremely accurate, measuring down to a 10th of a liter, the councils likes this level of accuracy. You should buy or somehow get hold of 2 of them. Install one after the fresh water pump, this then shows how much water you have used.
Put the other one on the end of the hose you use to fill your tanks. Now you can measure the amount of water put in and the amount going out.
This way you can measure down to the liter how much water you have left... as well as many other interesting things like how much water is used when certain people take a shower.
 
This is similiar to what I thought (you don't need a flow meter on the tank fill, just a button to press when the tank is refilled).

I've started knocking up a circuit design for this, and a friend of mine is very good at electronics...

Steve
 
Try www.snake-river.org . they produce a complete range of guages for one - four tanks and non-invasive depth readers.Just about to order some for my Catalina 42 on the recommendations of other Cat users in the States.
 
You can fit a transducer called a proxister to the outside of the tank, this will measure level at only one point tho, so could be set up to warn you of low level or 3/4 empty. Its non invasive so you can just fix/clamp/glue it to the outside of the tank and it will sound a buzzer or flash a light -should be available from Farnell or RS. you need to fill and empty tanks to tune it in. If youve got loads of dosh to spend you could fit a pressure transducer to the tank outlet by T piece and tune the read out scale to read tank contents by pressure, but this will only work when no water is being drawn off-its wot some big ships have.

You also fit a tee in the line as others have said a fit a sight glass/tube. but depending on tank position these can be hard to read.
 
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Try www.snake-river.org . they produce a complete range of guages for one - four tanks and non-invasive depth readers.Just about to order some for my Catalina 42 on the recommendations of other Cat users in the States.

[/ QUOTE ]

These look good but the non-invasive ones require a plastic tank and mine are stainless steel.

Steve
 
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Maybe this would do. Look under boat and RV tanks at www.hendersons.co.uk
They have a clever little in-line unit.

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That is an interesting solution - pressure - I hadn't thought of that (and probably much simpler than my solution he says putting down the book on programming PIC processors).

There are 2 tanks on Harlequin, one each side with a balance pipe in between. This sensor could be put on that pipe quite easily.

Steve
 
Balance line ...

If you have a balance line .... can't you fit a T piece and a sight tube to exit and be viewable somewhere else ?
 
Re: Balance line ...

Not really - It will still mean pulling up the floor to get into the engine bay and getting in with a torch. I think I might try one of the pressure systems mentioned above as my tanks are mostly square.

Steve
 
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