GFL built-in duct sensors are used to measure the temperature of liquids and gases in pipes, air ducts or tanks. A special installation fl ange (MF) isrequired when installing the sensor in an air duct. If the sensor is to be used in liquids, nickel-plated brass dip sleeves (THMs / 200) are required. In aggressive media, the use ofstainless steel (V4A) dip sleeves (THV / 200) is recommended. Dip sleeves and installation flanges are notincluded in standard delivery and must be ordered separately as accessories.