Content level sensor for stationary ship tanks Nuova Rade 197348 with a working surface length of 20 cm is designed to monitor the level of liquids (water, fuel, etc.). The operating principle of the sensor is based on the ability of a reed switch to change its state under the influence of a magnetic field. When the level of the content in the tank changes, the output resistance of the sensor changes (from 0 to 190 ohms), which becomes a signal proportional to the level of the liquid.