Virtual Hydromet” make Water Level Sounder is a reliable instrument for measuring the water level and total depth in boreholes, wells, reservoirs etc. For the measurement the bob is lowered to the water level. When touching the level, a sensor effects the illumination of a signal lamp & an additional acoustic signal will be released by a buzzer. When the probe is touching the water-level there is a conductive connection between the tip of the probe and the sensor-body. Thereby a circuit of the lamp and the buzzer will be closed.