This is about several diesel tanks that need to be monitored in terms of diesel volume. I want to measure and monitor the volume of Diesel liquid inside horizontally cylindrical tanks with standard dimensions, however the safety rules are strict, where no electrical devices or wires has to exist in the tank zone, which limits the solution to few methods or devices. What i want to achieve is to measure the diesel volume inside the tank without having to use an ultrasonic sensor, as it will require some modification to the tank, not mentioning the wires connecting from the transducer to the display unit. the question here is whether we can use a sensor that can be attached to the output pipe of the tank and calculate the diesel volume. a sensor to measure pressure or flow, will it work for such requirements ? If yes, how do I calculate the volume based on those values ? and is there's any device in the market that can provide the volume of liquid inside the tank straight forward without the need to make any further calculations using the outlet pipe ? The tank is similar to the one in the picture below.