sensor for fuel tank

[simonpp82]

Hi ausfishers, Just after some ideas on whats available out there to measure fuel levels in my fuel tank. My problem is that my the alloy tank is fixed into the centre console and there is no way of seeing in, probing or feeling to see how much fuel is in the tank. Fuel is fed in via the side of the console with a fuel cap fitting and connecting hose to the tank. The electronics i have are a furuno fcv620 and garmin 176c, as far as i can see neither of these units have any fuel sensor option available. Im a bit clueless when it comes to gadgets and technicalities, so im unsure whats out there in the way of sensors etc and how to set it up. Any help would be much appreciated - simon.

[PADDLES]

hi simon, if your tank is above the floor line it might be possible to do something that a mate used to do in his racing car for a fuel tank mounted in the boot. you fit a brass elbow into the side of the tank somewhere near the top with the elbow pointing downwards. you do the same somewhere near the bottom of the tank with the elbow pointing upwards. join the 2 elbows with a peice of clear fuel resistant hose. presto ................... instant sight glass for fuel level.

[finga64]

Can you get to the top of the tank to see if there's a round cover plate that's about 100mm diameter?? A lot of tanks have these to clean the crap out of the tanks.
If there is a round cover a fuel sender unit (very much like a car sender unit) can be placed here and a fuel gauge is put up near your controls.
Cheers Scott

[Cruiser]

If you can't access the tank to install a sender unit (and gauge), you might have to consider a fuel flow meter such a the Navman.

Although mainly used to measure instantaneous fuel flows, the unit can also be used as a fuel gauge. You just tell it how many litres the tank holds (when you fill it) and it can calculate the fuel remaining based on fuel flow and time. Pretty accurate too (probably better accuracy then a normal tank sender unit and gauge). Costs more money than a norma gauge set up though.

Some later outboard motors (such as Yamaha) have a fuel gauge built into their digital speedo (or tacho) but you still need to add a sender unit.

Chris.

[SgBFish]

Simon what sort of boat do you have and how big is the tank?
It would be unusal to have a tank you can't access that doesn't have a sender unit already built in.

Some builders do seal their tanks in but allow access via inspection ports. You may need to put a port in the floor if there isn't one already.

Sounds like a job for a pro as cutting or playing near tanks is dangerous!!
Once you have the sender in place the simplest way is to put a level guage in the floor.
Good luck.
Scott

[simonpp82]

Thanks for the replies guys... The boat is an ex commercial longboat which has been converted to a centre console. The fuel tank was a seperate thing and after fooling around we decided to fit it inside the console permantly sitting a few inches off the floor. Its about 60litres and tank doesn't have any ports or anything, so its not your average tank. It will need some fiddling around with and im lost as how to do it without spontaneously combusting! I liked the simplicity of the clear tubing on the outside to view the levels. Something simple and cheap if possible would be my preffered option.