文档介绍：IEEE SENSORS JOURNAL, VOL. 10, NO. 11, NOVEMBER 2010 1691
Modeling of Infrared Gas Sensors Using
a Ray Tracing Approach
Johann Mayrwöger, Peter Hauer, Wolfgang Reichl, Reinhard Schwödiauer, Christian Krutzler, and
Bernhard Jakoby
Abstract—Many gas molecules absorb ic radiation
at characteristic wavelengths in the infrared region. This absorp-
tion can be used to identify defined substances like CO2, ammo-
niac, and so forth. A lot of different types of gas sensors are based
on the principle of infrared absorption like photoacoustic sensors
(., Golay cells), dispersive infrared instruments (., utilizing a
diffraction grating), or Fourier transform infrared (FTIR) spec-
trometers. However, the monly used types of infrared Fig. 1. Sketch of a NDIR gas sensor system containing the IR-source, the
absorbing gas sensors are nondispersive infrared (NDIR) sensors. sensor cell with reflecting walls, a gas specific filter, and the IR-detector.
Such a NDIR gas sensor consists of some basic function blocks,
., an IR-source, the sensor cell or optical path containing the
sample gas, a gas specific filter, and an IR-detector. One of the cen- the sample-gas in the sensor cell absorbs radiation at its char-
tral issues in the design of this kind of sensors is the geometry of
the sensor cell. In this paper we investigate the use of statistic ray acteristic wavelengths,