The H series of sensors is based on Hall Effect sensor technology, which can sense a change in target motion from true zero to 20 KHz. These sensors incorporate a magnet within the sensor, enabling them to sense ferrous metal as well as magnet targets and can be optimized to detect fine as well as large pitch targets. These sensors integrate a preamplifier/signal conditioner within the sensor housing that provides excellent noise immunity and greater transmission capability. They also have a unique circuit design that offers complete protection in the event of connection mis-wiring. The output frequency of these sensors has a square pulse waveform (digital) that directly relates to the number of turbine blades, gear teeth, etc. that have been sensed. These pulses, in turn, can be correlated to determine flow rate, RPM, or velocity.