Precision and accuracy in the measurements of responsivity

In this work we discuss some error sources in the determination of infrared sensors responsivity, identifying, quantifying and, when possible, proposing ways of minimize them. The errors may happen on the reading of electrical signal, or on the illumination of the sensor under test. When reading the electric signal, noise may be read as signal, even when using a lock in amplifier, and also signal intensity may be lost on the electric cables and connections, before reaching the pre-amplifier. During illumination of the sensor, geometrical distortions, unplanned reflections, radiation partial obstruction and atmospheric absorption can make the calculated signal intensity unreal, even if the source itself is a very good one.