Normally, a thermocouple can only be effectively checked with the use of another thermocouple. Delta HTP/HTX thermocouples are normally furnished with multiple elements, continuously providing redundant output signals. It is not possible to directly verify the accuracy of a thermocouple with an Infrared device (Delta Model HIR or any other.) Since the thermocouple is a spot temperature measurement, and an infrared device measures an average temperature of the surrounding area (due to reflections), it is possible that a properly working thermocouple will read a different temperature than a pyrometer that is pointed directly at the thermocouple. However, if the thermocouple is compared to the pyrometer over time, a trend can be noted. Changes in the trend can indicate developing problems. For example, a decreasing thermocouple indication relative to the pyrometer can indicate that the thermocouple is becoming corroded. A decreasing pyrometer indication relative to the thermocouple can indicate that the pyrometer window is being coated with sulfur. A simple and convenient means to check either the HTP/HTX thermocouple or the HIR Pyrometer is via the use of the CLAUSTEMP Model HIP Handheld Infrared Pyrometer.