Nondispersive IR analyzer prototypes have been
fabricated with sensor head which consists of sample and reference PbSe photoresistors
(R=300 KOhms, 300 K) as detecting elements and several LED chips all mounted together on
the same plate as shown in Fig. ( see [1-4]). The LED emission (4.3 μm for CO2
and 4.6 μm for CO detection) was focused onto the sample
photodetector by a concave mirror. The mirror was isolated from a gas by a ZnS window
limiting the sample path length to 5 cm. To utilize LED edge emission microreflector has
been mounted together with LEDs. Similar sensor design was used in GIAM-302
portable analyzer for the CO2 gas some years ago.
Modern gas sensors utilize InAs(Sb) photodiodes (PDs)
[5] instead of PbS and PbSe ones. The advantages of PDs are low noise and
small response time. However, all semiconductor components are temperature
sensitive and
additional
measures are to be undertaken for high accuracy device
design.
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vol.2069, Optical Methods for Chemical Process Control, Boston 7-10 September,1993,
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InAsSbP/InGaAsSb infrared diode lasers as a source for gas sensors ", Infrared
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3. B.A. Matveev, G.A. Gavrilov, V.V.
Evstropov, N.V. Zotova, S.A. Karandashov, G.Yu. Sotnikova , N.M. Stus', G.N. Talalakin and
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4. B. Matveev, M. Aidaraliev, G. Gavrilov,
N. Zotova, S. Karandashov, G. Sotnikova, N. Stus', G. Talalakin, N. Il'inskaya, S.
Aleksandrov ”Room temperature InAs photodiode-InGaAs LED pairs for methane detection in
the mid-IR”, Sensors & Actuators Vol. 51(1998), No. 1-3, pp. 233-237
5. Sotnikova, G.
Y.; Gavrilov, G. A.; Aleksandrov, S. E.; Kapralov, A. A.; Karandashev, S.
A.; Matveev, B. A.; Remennyy, M. A. "Low Voltage CO2-Gas Sensor Based on
III–V Mid-IR Immersion Lens Diode Optopairs: Where we Are and How Far we Can
Go?" Sensors Journal, IEEE Volume 10, Issue 2, Feb. 2010 Page(s): 225 – 234
Digital Object Identifier 10.1109/JSEN.2009.2033259
