E Instruments BTU4500-S Commercial & Industrial HVAC Combustion Analyzer with Built-in Printer is ideal for emissions monitoring, maintenance, and tuning of combustion processes such as burners, boilers, gas and diesel engines, turbines, furnaces, kilns, laboratory analysis, and heaters. The BTU4500-S features a handy external water trap for quick and easy condensate removal, integrated impact printer for easy portable printing, datalogging up to 2,000 tests, and much more. *Equipped with O2, CO, CO2, NO, NOx and SO2 Gas Sensors.