Robert Shaw thermopiles are the industry leader for gas appliance applications. Their primary function is to ensure a standing pilot light is operative so that on a call for heat, the main burner gas will be properly ignited. Thermopiles are placed in gas applications to detect the existence of a flame for safety purposes by shutting off the potential gas flow to a burner. A thermopile is the assembly of many thermocouples to increase the millivolt output. Robert Shaw thermopiles have two types of connections: coaxial and two-wire spade connectors. The 1950 thermopiles, also known as tp-75, are two-wire spade connectors. The 1951 thermopiles, also known as cp-2 (500-600 millivolts) are coaxial connectors. The 1950 and 1951 series thermopiles (pilot generators) are designed for use on self-powered gas control systems. They can be used to replace similar competitive devices.