Since the gas flows to the burner at a fixed rate, any changes in temperature are proportional to the heat release of the gas. The calibration gas is automatically switched and after a short calculation period, any drift from the programmed values are eliminated. The analyzer also electronically compensates for small changes in ambient temperature as they occur. No specific tools are required for servicing and the thermopile and gas filtration elements are all easily removable for cleaning if necessary. The thermopile heat of combustion detector is at the heart of each heating value transmitter.
Air is used as a heat transfer media and flows around the combustion chamber.
Any increase in the heat produced by the combustion of a controlled sample of process gas is immediately sensed and reported to the microprocessor. The mixed gases then flow over the hot junctions of the thermopile before being exhausted outside the analyzer. Combustion calorimeters have been around about as long as the gas industry itself. Their reputation as a maintenance item was earned by early designs that made use of thousands of parts operating mostly in a water bath contaminated with flue gas acids. If you've ever imagined your day spent doing other things than calorimeter maintenance, then you owe it to yourself to look seriously at the Model 95 Heating Value or Wobbe Index Value Transmitters.