The Smith Meter Model PA-6 Preamplifier is designed to be used with the Smith Meter Turbine Meters and D Transmitters (on PD Meters) to convert the low voltage sinusoidal signal to a square wave pulse form that can  be used to increase the transmission distance of the pulse or convert the pulse form for instruments that require a  highspeed, edge-triggered input. The preamplifier has also been designed with a jumper-selectable gain that can be used to either increase or decrease the sensitivity of the unit to fit the needs of the application.