What is Time Constant? Time Constant is the period of time over which the values measured by a detector are averaged. On most applications the time constant is 30 to 60 seconds. Why is Time Constant Important? It is necessary to minimize noise. The output signal from a detector is not the process value at that instant. It is an exponentially weighted average of the values recorded over the time constant. All measurements have noise – or statistical fluctuations. This noise is generated from the inconsistency of radioactive decay, but can be minimized when the values are averaged. The greater number of values (longer time constant), the less impact noise has on the measurement.
VEGA INSTRUMENTS (2016) What is time constant and why is it important?