Trasmitters are electronics that would allow the transducers millivolt signal output to be processed and converted to current for transmission over long distances. Since current are virtually unaffected by radio frequency interferences unlike voltage which are sensitive and to it and would add noise to its reading in addition to being intolerant to resistance, usually a two-wire transmitter is used with 4-20mA output. A three-wire transmitter has also been developed to have an output of 0-20mA signal.