The Data Industrial IR Series flow sensors are “environmentally hardened” versions of the standard DI flow sensors. These IR versions are specifically designed for installation in underground vaults and outdoor locations that might be subjected to flooding. The IR Series feature a six-bladed impeller design with a proprietary, non-magnetic sensing mechanism. The impeller shape coupled with the absence of magnetic drag provides accuracy and repeatability throughout the flow range of the sensors. As the liquid flow turns the impeller, a low impedance 8 VDC square wave signal is transmitted with a frequency proportional to the flow rate. This signal can travel up to 2,000 feet between the sensor and the display unit without the need for amplification. The sensors are configured with two 48 inch single conductor leads.