These results are preliminary. ASTM E1602 currently specifies a maximum surface temperature of 230F for masonry heaters, with unspecified fueling. Stack of brands visible to the right of the clock. Simultaneous data were taken by OMNI with calibrated thermocouples, using an automated data aquisition system, shown in the first photo, above. The IR thermometer data is shown in the graph below.
Temperatures are in degrees Fahrenheit.
Download the data in Excel 97 format.