Ultrasonic Measurement of Steel Tank

[Goature]

Hello all! I have this steel diesel trailer. I want to measure the level of the tank, but I don't want to put anything electric inside - for obvious reasons. I've therefore been thinking of putting some ultrasonic sensor on the outside of the tank (probably on the bottom), that measures the level from the bottom and up. Does anyone know if this is feasible? Are there transducers that are strong and/or cheap enough? Are there other methods that are better?

I've found this transducer: http://www.prowave.com.tw/english/products/ut/ep/40ep250.htm

PS. The walls of the tank are quite thin, just a couple of millimeters.

[Marco]

Seeing as they are being sold I'd say it is feasible

[Goature]

Seeing as they are being sold I'd say it is feasible

Thank you! Very neat, that is exactly what I need! Ok, so now that i know it works, I want to build my own! I suspect that the probe is some sort of piezoelectric microphone/speaker/buzzer... Does anyone know if a normal cheap-ass piezo-buzzer would work as a transducer, or do I need some other type of piezo?

[trevwhite]

Well you could experiment and use one of these..

http://www.ebay.co.uk/itm/LED-Display-Car-Parking-Rear-Reverse-Kit-Buzzer-Radar-8-Sensors-4-Front-4-Rear-/221354076731?hash=item3389bb2a3b:m:mALVAH24f-cmCP0SSw0jzRw

I do not know how high the tank is but maybe the transducer could be used to measure the depth from the top to the level? Just an idea.

[_Andrew_]

I use BEP Marine ultrasonic fuel level transducers on the deisle fuel tanks of my generators and fuel bunds. There pretty accurate, very flexible with resistive output which can be configured to work with many common gauges / displays / fuel management systems, 0 to 10v voltage output that can be customised. They also can be set up for tank linearisation for shaped tanks.

These ones fit in the top of the tank (hole does gave to be cut) but a gasket is supplied with the sender unit

They do have to be programed for the tank dimensions and fare few suppliers will program it for you if the dimensions of the tank are supplied. A programmer unit and software is also available which is responsibly easy to use. You just need a windows computer, PP3 battery and depending on what type of ports you have on your computer either a 9 pin D RS232 cable or USB to RS232 cable.

http://www.ecs-marine-equipment.co.uk/marine-equipment/bep-tsi-ultrasonic-tank-sender-item-25932.html

If I remember correctly these are manufactured in New Zealand and seem to be avaliable globally. The example above is the company I get them from in the UK.

For the aplicacion I use theses for I needed to know percentage fuel left, volume of fuel in the tank in liters and the ability to automatically activate a fuel transfer valve to switch tanks from an empty tank to a full tank with out interrupting the operation of the generators. So coupled these sensors to an arduino and spun a bit of code.

[Marco]

Use two piezo discs, put some weight behind them, put a chirp on one, use the other one as a receiver and mix it's signal with the chirp, high pass in analog to remove the direct signal and echos from the metal transitions and put it into a =>16 bit ADC to find the frequencies/distances of echos.

OR spend a couple hours doing literature research on what's actually the most sensible way to do it