High Performance Infrared Gas Measurement System Based on a Semiconductor Gas Sensor IR Source with Tunable Fabry-Pérot Filter

摘要

In this work, a miniature infrared (IR) spectrometer for gas analysis was realized by using a microstructured Fabry-Pérot interferometer as a tunable filter. Two of these filters were applied for two different wavelength ranges (3.9 to 5.0 μm and 8 to 10.5 μm, respectively). Thus, a wide range of gases can be detected and quantified. A semiconductor gas sensor was used as IR radiation source. With filter modulation frequencies of several Hz, optical spectra can be recorded quickly and several gases can be monitored simultaneously. Furthermore, a computer model of the system was created which describes all the steps of the measurement chain and calculates the influences on the measurement at each step. To generate the models of the Fabry-Pérot filters (FPF), for example, the devices were characterized using Fourier Transform Infrared (FTIR) spectroscopy. Gas measurements were performed in the two wavelength ranges to demonstrate the functionality of the system’s operating mode as a low cost spectrometer.