Nova Model 304B analyzes endothermic gas from a furnace or generator. It uses a microprocessor infrared detector for accurate measurements within the range of -20 to +80F (-30 to +27C). In addition, the microprocessor calculates the carbon potential of the sample gas when the furnace or generator temperature is input. The unit operates on a rechargeable battery and has a bright LED digital display and built-in sampling pump. A 4-20 mA output is standard.