1m deep tank sender units???

[vas]

Since it looks like I have just enough space for an extra gauge on my new dash design, I was thinking of the benefits of installing a fuel gauge...
ATM, I just go down to the e/r and see the trans tube with the nicely handwritten marks. Lovely

considering there are 4 tanks across the width of the craft, interconnected with the two side ones obviously slanted and of smaller capacity, I start with the problem that once under 1/3 measurements wont be linear and hence way off...
I also have the more fundamental problem of getting hold of a sender unit that does measure 1.2m or so. Had a look at VDO gauges and sender units and all are arms and levers up to 600mm or so, so no good. I'm aware of capacitative ones that work at any depth, but not found them and not sure I can easily wire them to the VDO (ahem, it's GOT to be a VDO gauge to match the rest, else I wont bother)

Any ideas?

TBH, I'm not extremely keen, just a thought, if it turns out that I need to spend 500-600euro for that, sod it, I'll just step down to the e/r and save the money for fuel...

cheers

V.

 

[kashurst]

could you extend and bend the float arm to create a bigger range of movement. obviously with slanted tanks it would not be linear but you would soon get used to that

 

[roofus]

http://www.wemausa.com/

they will make to lenght req

 

[Spi D]

The do come in many types. You can use an universal as long it has the rigt ohm range, for VDO often 0-180 ohm (but not always).

If you have to compromise, a sender that can show pretty acurately from empty to somewhere between half and full is adequate. Better a reliable reading when approahing empty...

This type is for up to 24" deep tanks.

 

[David2452]

Good old coastal rides have a new old stock clearence Wema sender @ £24.00 + VAT at the moment.

http://www.coastalrides.com/index.php?act=viewProd&productId=1932

 

[Bandit]

If you want a proper job a measurement of what is in your tank rather than a vague indication if you have fuel in your tank try Tank Tender gauges.

I have fitted them to three of my boats now and at refuel time I can tell you to within 10 litres how much I can take in each tank (1250L).

You can get a single set for many tanks fuel, water, black water etc.

When fitted preferably empty the tank then fill 25 or 50 litres and measure and plot on a table or graph. they say they are accurate to within 1/4 inch 7mm.

http://www.thetanktender.com/

made by Hart Systems, thert is a dealer in the UK IMP.

I have no conection with manufacturer or dealer just a satisfied end user.

 

[boatmike]

I know you are in Athens but if you look at ASAP supplies website you will find them at any length you require. They will indeed work with VDO gauges and the only thing you need to know is if your gauge requires USA imperial or metric resistance. They will mail order anywhere as far as I am aware if you can't find a more local supplier.

 

[vas]

thanks a lot guys, learned a lot about the options by checking the websites suggested

The Wema looks like a v.good idea, simple, should work and close to what I'd be willing to pay. Unfortunately the special offer one is too short for me
The tank tender is too serious and too expensive, I'd rather go down stairs and check with my eyes and spend the money on a radar or plotter even (OK most likely neither, just fuel!)
Mechanical don't seem to be able to do it for that tank depth and width...

However, had a talk with the guy that develops the BMS system I'm using at home and will install in the craft and he told me that they have 2 ways of measuring liquid in tanks (to be used in static diesel tanks for home c/h, and/or water/waste tanks)

The easy one is a pressure sensor (you T off the tank outlet at the bottom and narrow it down to aircomp 3.5mm thread) that is calibrated in s/w and is accurate to 2-3cm (more than enough for me tbh!) Cost 70euro each
The other option is an echo sounder on the top of the tank calculating the distance to the bottom. Good for black water tanks where pressure sensors can be easily blocked... Cost 300euro

Now, having the BMS components, the cost for adding a sensor for diesel and another for water will be 140euro. Stock BMS display will be reporting in real time the values so no extra costs for gauge Not to mention that I don't need to empty tanks, drill holes on top of them etc...

So looks like I'll go down this pressure sensor route. Anyone have any objections/bad experiences with such devices?
I expect them to be inaccurate in bumpy seas but reasonably accurate when stationary or moving at constant speed and conditions. Else, it's easy enough to sample values over 20sec, process them in s/w and present the average on screen

ideas?

V.