Previous papers described wireless devices (motes) for measuring the temperature of the gas in ventilation ducts from smelting pots, and the heat flux through the pot shells. This paper describes more extensive, longer term measurements of duct temperature carried out on ten pots at a smelter in 2006. Measurements were carried out for 43 days and 1.3 million temperatures were recorded, along with simultaneous real-time measurements of roofline HF concentration. The duct motes were self-powered using thermoelectric generators operating off temperature differences between the duct gasses and the surrounding air. Temperatures measured by the motes reflected all pot-work such as removal of cover panels or opening of end doors. Even after elimination of temperatures during active pot work, significant variations in duct temperature were observed, both from pot-to-pot and from day-to-day on individual pots. The variations in pot duct temperature exhibited a good correlation with roofline HF concentrations.