Gordo, what do you know about fuel tank gauges

[Chief Engineer]

sending units?

Other than the Tempo/Moeller types?

We await your wisdom......seriously

[never monday]

what are you looking for. There is a standard to the ohms of them . I want to say 65-200

[Chief Engineer]

I've got two large diesl tanks in a trawler.

I was wondering what other options are available other than the lever/float system.

I really like sight glasses but I was told they are not legal anymore.

[never monday]

I've seen a few around for the new NEMA 2000 systems that use a long tube without a float.

[GordMay]

Now that’s a loaded question.
There’s not that much to know, and I do know “some” of the facts; but not certain I've any "wisdom" on the subject.

I'm at home, so don't have access to my incredible hard drive (& ABYC recommendations ...)

Tell us your diagnostic problem, and perhaps someone can offer specific advice.

Fuel Gauges are usually the Voltmeter type, which receives it’s reference voltage from a Sender unit, mounted on the Engine. The Sender resistance varies with changes in Level. As the sender resistance increases, the reference voltage transmitted to the Gauge decreases (Ohm's Law).
Dual Station Senders will have Half the Resistance values of single-station senders.

Gauges that use a “long tube, without a float” may be pressure gauges" (like the Heart Tank Tender).

I believe that "Sight Glass" indicating systems remain "legal" .

ABYC on sight gauges: standard H-33, Diesel Fuel Systems.

33.5.10 A means to determine fuel level or quantity shall be provided. If a sight gauge is used,

33.5.10.1 it shall be equipped with a shutoff valve at the top and at the bottom of the gauge, and

33.5.10.2 a warning label shall be placed adjacent to the sight gauge, and

33.5.10.2.1 the warning label shall comply with the requirements of H-33.16 .

In another part of the standard, it mentions that every componant of the fuel system must be "permanently mounted...and independantly supported"...and I think this next one rules out vinyl hose:

33.5.2 The entire system shall be liquid and vapor tight to the hull interior.

American fuel gauges usually read Empty at high resistance (240 Ohm), and Full at Low resistance (33.5 Ohm).
European Fuel gauges usually read Full at high resistance (180 Ohm), and Empty at Low resistance (10 Ohm).
The difference (between Ami & Euro) lies not in the gauge or sender, but only in the orientation & calibration of the display.

See also:
http://www.cruisersforum.com/forums/...sting-645.html

http://www.cruisersforum.com/gallery...r&imageuser=79

http://www.cruisersforum.com/gallery...r&imageuser=79

[AnchorageGuy]

Chief, We used the Tank Tenders for years and they were fantastic. Always accurate, never failed and were oh so easy to install. Don't rule them out.

[Chief Engineer]

This board is going to make Google obsolete

I liked that one image a while back that was "Gordle" or sumfin like dat.

Thanks for the prompt replies on this cold wet rainy day in Baltimore.

[irwinsailor]

I have tank tender for my four tanks and it seems to work ok but from time to time I double check how many inches with a dowel.

[AnchorageGuy]

Chief, Cold and rainy here in Beaufort, SC so nothing else to do.

IS, How many times did you check with your dowel and find the Tank Tenders incorrect?

[CSY Man]

I use WEMA for both fuel and water tanks.

WEMA USA, Inc. Home Page - Boat fuel, water and holding tank level sensors and related instruments



Just like this board and yours truly, they are from Norway and of excellent quality.

[Inthewind]

A tried and true method that never fails and is very accurate is a guaged dip stick. Thought I would throw that in there for the simple minded folks.

[Lancerbye]

I use the Tank Tender for Fuel, Water, and waste. So simple and so accurate.

[Stranded Mariner]

Originally Posted by never monday

I've seen a few around for the new NEMA 2000 systems that use a long tube without a float.

I have seen those before as well. The tube is basically a capacitor, and the capacity changes with the amount of dielectric medium, in this case fuel or oil. No moving parts, so not much can go wrong with the sensor.

[Stranded Mariner]

Originally Posted by Chuck Baier

Chief, We used the Tank Tenders for years and they were fantastic. Always accurate, never failed and were oh so easy to install. Don't rule them out.

I read something about that before (Maybe even on this forum). Isn't the principle that the system measures the back pressure on a sounding pipe, which changes with hight of the medium in the tank?
We used to sell industrial systems like that, and they are very reliable.

[James S]

I also have the Tank Tender for Fuel, Water, and waste. I have a total of 6 tanks...with the possibility of adding two more.