Durex Industries, Cary, IL, offers a line of heavy-duty thermocouples for pollution control and process applications. The sensors can be protected from hostile environments with thermowells or SS, nickel-alloy, ceramic, or silicon carbide protection tubes. The company offers various terminal housing to comply with NEMA standards. Thermocouples meet applicable ANSI and ASTM specifications and have standard tolerances or special limits-of-error. The thermo element design can be single or duplex for multiple outputs from the same point. Head-mounted transmitters are available for 4–20 mA signal conversion.