fuel gauge accuracy

[sam]

I do not rely upon the indicated level as shown on the fuel gauge, but keep a solid record of all fuel used. (averaging 0.7 GPH over time-no generator). However, I would like for the unit to roughly indicate some state of fill other than perpetually full. I have not attempted to sort out this issue yet, but thought I would ask the all knowing list for experience first.

This forum has really become a source of help and sharing.

Sam

LONGHAWK

[David]

Hi I have a two cabin and it was not difficult to replace sender unit with the revised factory part with bent arm. Although you need to remove everything from port lazarette remove a few screws from the dividing wall, lift floors and timber beam. (But it would not be possible if a generator is in this location).

I intent to install a programmable NMEA2000 Tank level converter (Maretron or Lowrance) to convert existing sender output to NMEA2000/SeatalkNG and then program it for tank shape. Hopefully I will then be able to accurately display fuel level and fuel remaining on all Raymarine Seatalk2 or SeatalkNG instruments via a SeatalkNG backbone.

Regarding the water tanks in my model, there are 5 screws/probes through the side wall of water tanks at quarter levels, hence gauge only reads in quarters, no sender as such.
David

[Luis Vieira de Sa]

Hello,

In the end of the summer season I intend to replace the original (bent arm) 180 ohm fuel sender with one like this  http://www.wemausa.com/tank_sensors/tank_level_sensors.htm . The replacement is just to unscrew the old sender and screw the new one; Because of the shape of the tank, the reading will indicate full until the tank is about 3/4. However, from this level I expect the reading to be "linear" and I can tolerate this as I find more important a clear reading when the fuel is near the end (well before that of coarse).

Regarding the water tanks, I have sanded the screws that David refers to, and I nearly resolved the problems. However, in one of the tanks, one of the screws needs to be replaced because it shows no connection to the adapter. That is my problem as I neeed to remove the tank to get access to the wall where the screw sits. This is not easy as there is a piece of wood that does not allows me to free the tank.

Best Regards, Luis

 

[Luis Vieira de Sa]

Hello,

It was almost 6 years that I participated in the discussions about water and fuel level indicators in this forum. Only this winter I had a go on it. In particular I made the following:

a) installed 10-180 ohms sensors in the 2 water tanks

b) replaced the 2 senders (those which connect by 3 wires to the VDO panel) with my own designed sender.

c) on the back of the VDO I activated one extra water level indicator (2 were in use but 4 are available)

d) run a 3 wire cable from the back of the VDO panel (port side) to the waste tank (startside)

e) add 4 non-contact water level sensors on the external surface of the waste tank and connect them to my sender (it works with different type of inputs)

f) and I get the level of the waste tank on the VDO display as "fresh water tank number 4" (I could not change these words)

I have some PCBs available for the senders (arduino based) and I plan to make the software freely available. I start my sailing season next week (Italy and Greece) and may be only in September I will describe in full detail what I have done. At this moment I only have some photos in my website:

http://www.vela-navega.com/index.php/tank-monitors

I will be happy to discuss this with interested people. Just send me a PM or use this forum (or my forum).

Best Regards, Luis