The sensor is used for continuous non-invasive, digital, automatic measurement of LPG level and other liquids such as water, chemicals. Sigma ULB measures the level mainly in aboveground stationary cylindrical metal tanks from 10 cm up to 4 meters depending of the liquid density. The sensor has measurement error from 5% up to 1 mm depending on the model. Can be installed in the 0 explosive zone. Sensor description The sensor is a device that consists of one or two ultrasonic emitters / meters connected to a signal converter. The converter is connected to intrinsically safe unit. The barrier is not included in the installation set and supplied as a separate, independent product. Sigma ULB has RS 232, RS 485 output and can be easily connected to GPS tracker, PC, notebook, smartphone or digital indicator