Response Time

The time interval between an abrupt increase or decrease in the temperature of a measurement target and the moment when the infrared thermometer reaches 90% of the signal strength of its final value at a signal output (analog or digital) is known as the response time. The 100% value corresponds to the difference between the final and initial temperatures.

The response time is strongly dependent on the detector technology used, particularly its time constant and whether the input pulse electronic signal processing of the measuring device is synchronized or not. With unsynchronized signal acquisition, this value can fluctuate by one cycle time (with pyrometers) or one image period (with infrared cameras), which can be relevant when recording fast events. The larger value must be specified in the device specifications. The response time must be distinguished from the exposure time, as the latter does not take the entire processing chain into account.