Fluid or gas inflow indicator - has primary magnet on float, with second magnet in tube interior separated from fluid

The fluid indicator has a primary magnet and a float and also a magnet in the tube interior, separated from the fluid and connected to a manometer. The tube, which contains the second magnet and the connection to the manometer, is surrounded by another tube at a distance from the first. The intermediate space between the two tubes is connected to another manometer. It indicates the inflow of fluid or gas or the outflow from the intermediate space. Elements are built into the intermediate space in order to maintain the space between the two tubes. The float slides along the double tube which houses the second magnet.