hello i heard about a project for measuring underground tanks petrol level it consists of sending a signal to the tank and aquiring back using fpga to determine the level and if any leakage occured?
but i do not get sending the signal part? at what frequency can we rely and why doesn't the frequency bounces back when it hits the ground for example? can i get a little clarification on how is this possible ?
it means that we have a tank placed underground and filled with petrol i need to measure the level of petrol in that tank from up the ground by sending a signal ......
you can use an ultrasonic sensor that you can find them as transmitter and receiver , and , we have an effect , that the speed of reflected , wave , will change , due to the oil or water or petroleum or ..... etc. and it's frequency can be about 20KHZ or 40KHZ .
Best Regards
Goldsmith
I don't know what accuracy you require but the speed of sound is not constant in air - it varies with pressure and humidity for example. Also, it is probably different in the presence of petrol vapour. It may be possible to reduce the effect by having a reference distance (object) for continuous calibration.
well that might be able to calculate how far am i from the peak of the tank i dont think it can caluclate the level of the petrol i wanted to try this without impelemting a sensor in the tank let say i send the ultrasonic wave how can i be sure that it hited the liquid and got back is there a specific wave that only returns upon hitting the petrol or a liquid?
No ! the sensors are face to face ( two side of tank ) .
And you have the maximum size of tank , and thus you'll have the size of petrol , that is in your tank . with a simple relations between them , you can find , that how much liters is in your tank .
( the sensor isn't in your tank )
Good luck
Goldsmith
If you have two sensors, one on either side of the tank, how does that give you the contents of the tank? What parameter are you measuring? How is that parameter varying with the amount of liquid in the tank?
I could envisage a system where you placed a sensor under the tank and looked for the reflection from the liquid/gas interface but you would need some good processing to sort out the correct reflection from all the others. It could then probably be done with a single sensor. The speed of sound in a liquid is more stable than in a gas, although it would probably need temperature compensating for good accuracy.