Analysis on Nondispersive Infrared Device Characteristics Using Thermopile

Abstract

In the design process, analysis of important parts of the device will help to determine whether the upcoming device can function and which working aspects should be adjusted to meet the designing criteria. For nondispersive infrared device (NDIR) using thermopile, the first condition is damage threshold power at which the incident infrared power must not exceed to avoid damaging the thermopiles. The second condition is the maximum power, in which the incident infrared power should not be higher than a certain level to avoid degrading the sensitivity of the thermopiles. This paper shows a method to estimate the radiation from an IR source and the incident IR power to the thermopile. Signal-to-DC error, signal to noise ratio and other parameters were also analyzed. The real device was used to verify the theoretical values. The results prove that the analyzing method is useful in design, select components, modify, and optimize NDIR devices to detect gases and biological objects.