Hi all
I need help in designing a wireless fuel level indicator for a storage tank.
I have thought in an hermetic device fixed inside the tank, in the bottom with some kind of pressure sensor. So, i can monitor the changes in the fuel weight and send an rf (could be fm) to a receiver outside the tank. It has to be an undetectable device. The idea is monitor fuel levels an give an alarm if the rate of lowering is faster than normal to avoid leakage or more important fuel theft.
The idea of pressure sensing is good but you will need to calibrate for different materials if they have different densities. (P = ρ*g*h)
A more common way is ultrasonic level sensors. These are commercially available, give accurate results, and are safe with your flammable material.
I hope the tank is plastic, because if it is metal, you are going to have a problem with the antenna. Also, a pressure device to measure fuel depth would be pretty hard to build. How many inches of the fuel equal one atmosphere? Your margin of error could be greater than the measurement. A float device is still the simplest and easiest way to measure a liquid level.
The ultrasonic suggestion seems very good. I found this:
**broken link removed**
It´s an excellent option for my purpose, but i need to incorporate a way to detect faster than normal lowering of level. Do you think the receptor could be modified or complemented to acomplish this.
There are two ways to detect faster than normal lowering of level.
1. Fixed time sampling:
detect level every pre determined time if the difference is greater than you
expected then you have faster than normal lowering of level.
2. Fixed difference in level:
A predetermined level is known upon reaching this difference in level the time
is calculated between the initial level and the final level.