The devices with the aid of buoyancy of float help in indicating the level of fluid in the tank
Transparent level gauge is best used in the interface liquid application and also liquid which are not colorless.
The liquid level rises in the tank, the liquid also rises inside the glass tube and one can see the the liquid level in the tank.
Reflex level gauges are designed to detect the difference in refractive indices of vapor and liquid and level detections.
The magnet on the float and the magnetic follower are coupled and move in union.