I have a home heating oil tank that is hard to get to so it occurred to me that I need to make a gauge that can be read remotely. Looking at the problem it seems like I have 3 different ways I can sense the depth of the oil in the tank.
A: Ultrasonic. This was my preferred method, but I am not sure if there are problems reading a return echo in an enclosed area.
B: Pressure gauge on the out feed to the burned. This I guess could also be fitted at the burner end of the pipe so I could monitor when the burner is running as that would give me a false reading.
C: Capacitance. I don't really want to plumb a plastic pipe on the outside of the tank to measure the capacitance as I see that as a safety issue, but I could use the tank as one electrode and lower a probe into the oil as the other.
Has anyone any experience of any of these methods that could give me the pros or the cons?
If your tank has a gauge, check and see if the piece that moves in the sight glass is magnetic, most modern ones are. If so you can put a reed switch next to the magnet and it will close when the fuel gets to a certain level.
Thanks for the info. I am pretty sure mine is not as its fairly old. I was looking for a gauge not low level indicator, I know there are wireless ultrasonic ones on the market and I had considered using there sensor. http://www.amazon.com/OEM-Rocket-7000-Wireless-Monitor/dp/B001W20K0A. I had also considered modifying my current gauge (float type) to turn a pot to give me a level.
Thanks for the info! The Etape looks like it would be ideal, I don't see where it comes in anything longer than 10" though. I have a 40" deep tank so this would come up a little short.
Personally, I like ultrasonic as you can place the sensor in the fill cap which will be a standard 1-1/2 NPT pipe thread. You can find some ABS or PVC [parts that will thread onto your fill pipe and place the ultrasonic sensor in there. Pot the whole thing in with a petroleum tolerant epoxy -- maybe JB-weld -- and the you can simply screw it on. If you change your mind, or get hassles from the oil supplier, just switch back to the old galvanized cap.
Ultrasonics were my first choice for easy install also. If I can use a probe in the same filler cap and use the metal tank as the other electrode then that is a pretty easy install also. Has anyone on here used ultrasonic depth measurement in a tank who can give advise? I suspect there is an echo problem and you have to have a defined return ping window to filter out the echo's? I am also thinking a narrow beam width will help, anyone got any advise about this?