Impulse Series continuous TDR level transmitter uses time domain reflectometry (TDR) to provide accurate measurement of total level, distance or volumetric outputs. It gives continuous level measurement of liquids at ranges up to 50 ft. (15 m), with a two-wire 4-20mA, HART output signal. It is made of 316SS and Hastelloy C for use in hazardous (Class I, Div. 1) environments with either intrinsically safe or explosion- proof installation requirements.