I have a 42 foot Recreational Vehicle that’s brand new fuel gauge is not working. To check and work on the sensor/sending unit will cost an arm and a leg (dropping the 180gl fuel tank, purchasing the sender and sensor, $200 per hour labor costs). I have found multiple made in China External Ultrasonic fuel sensors that adhere to the bottom of the fuel tank. First, has anyone heard of this? Second, does anyone know an American company that makes these sensors? And thirdly, do they work?
I am attaching the links to 2 different ones made in China for you perusal.
Also if anyone knows how to make one of these, please let me know.
I've seen a couple of reports on those too, one I think was from a beer brewer who reported that it did the job. I've been planning to experiment with them but -- other distractions.
Ok one more question, and I appreciate your help.
Would the item you suggesting be as accurate as the one from the ABEST METER I linked in my initial message, ESPECIALLY while my vehicle is moving down the road. ABEST METER states that their electronics will take movement into consideration while calibrating the fuel level.
Probably not, but my guess is that averaging a few readings would take care of sloshing effects. But it was just a suggestion to try.
If you don't mind the cost of the first item, by all means try that out! On this forum, you will very often see complaints if a sensor costs more than a cup of coffee.
In general ultrasonic sensors in liquid can be very accurate due to the fact that they are timing based and µP are excellent at timing.
Your issue will be slosh and angle, not accuracy. Don't under estimate the amount of slosh in a fuel tank. Even going down the road at an even speed the fuel will be everywhere. So you will have to average a significant number of readings to even get close. A good thing to know is the level of a filling station has a max inclination specification (unfortunately I don't recall the value). It is typical of level sender algorithms to sense the absence of slosh and the presence of increased level to reset the slosh value.
I worked for a company that makes automotive fuel tanks. I've done a significant amount of work on level senders and talked to the mfg engineers who write the code for the Level senders.
Did you install it or did some service business do it? Did it ever work? My old Dodge truck has a 20 gallon tank that is very long. On the level garage floor it will show 3/4 full, but driving down a slight incline will show 1/4 full. You will have similar problems.
By the time you’ve got this working it would be easier to drop the tank out and repair it.
Have checked the wiring , tank earth , resistance of existing sensor ?
Is this a boat ?
Are you sure the tank has to come out ?
$200 per hour is a bit steep…