The self-cleaning Model 640S from Sierra is designed for demanding industrial gas mass flow measurement applications. Constructed of heavy-duty 316 stainless steel wetted materials, the Model 640S is suitable for dirty flows where residue buildup can occur on the sensors, reducing accuracy. Direct gas mass flow measurement uses the company’s Dry-Sense technology for drift-free performance, while a Smart Interface Package offers field programming and meter validation and diagnostics. During tire manufacture, the system uses compressed air and a cleaning nozzle to blast particulates away from the thermal sensing elements when rubber particles clog up orifice flowmeters. At coal-fired power plants where combustion air is preheated to temperatures approaching 500°F (260°C), the self-cleaning unit reduces maintenance time.