Figaro sensors

Tin oxide Resistance Neodym Systems 0-20,000 ppm Yes Uses Figaro sensors, but selectively ... 

Chemical modulation of the surface conductivity is the principle of operation of some of the most commercially successful chemical sensors, the high temperature semiconducting oxide sensors. They are known by their brand name Figaro sensors. They are discussed in detail in Section 8.2.2.1. The reason for their commercial success lies in the fact that their performance and cost match exactly the specific practical needs of many applications, particularly those of the automotive industry. They have been described in great detail, from the point of view of both the underlying physics and chemistry (Morrison, 1994 Logothetis, 1987). 

Fig. 8.3. PCA sores plot for measurements with a lab-made e-nose (array of 6 Figaro " sensors) in a composting plant. The high variance of the data is due to the variability of the operating conditions.

We introduced the results of measurements of the response of the Figaro sensors and our samples made of Sn02 and PSi (Figs 12.5 and 12.6) (Aroutiounian et al, 2009). We see from Figs 12.5 and 12.6, the dc resistance response measured by the classical method, led to smaller values of the... 

In biomedical sensing, some of the solid-state devices based on thermal sensing cannot be used effectively. The reason is that the sensor itself has to be heated or is heated quite hot by catalytic surface reactions. Thus pellistors (oxides with catalytic surfaces and embedded platinum wire thermometer), chemiresistors, and Figaro sensor smoke detectors have not found many biologic applications. 

Madou MJ, Morrison SR (1989) Chemical sensing with solid state devices. Academic Press, San Diego, CA, London Mandayo GG, Castano E, Gracia FJ, Qrera A, Cornet A, Morante JR (2003) Strategies to enhance the carbon monoxide sensitivity of tin oxide thin films. Sens Actuators B Chem 95 90-96 Massok P, Loesch M, Bertrand D (1995) Comparison for the between two Figaro sensors (TGS 813 and TGS 842) for the detection of methane, in terms of selectivity and long-term stability. Sens Actuators B Chem 24-25 525-528 Matsuura Y, Takahata K (1991) Stabilization of SnO sintered gas sensors. Sens Actuators B Chem 5 205-209 Meixner H, Lampe U (1996) Metal oxide sensors. Sens Actuators B Chem 33 198-202... 

One of the earliest SnOi sensors, designed by N. Taguchi, is referred to as the Figaro sensor (see below). Sensors of this type make it possible to detect as little as 0.2 ppm of an oxidizable compound such as carbon monoxide or methane [29]. Nevertheless, certain details of the associated sensing mechanism are still not fully understood theoretically. An important aim of current research is to overcome limitations of the present generation of sensors, estpecially instability, irreproduci-bility. and nonselectivity [30]. 

There are several (commercial) applications for discrete gas sensitive devices. Two classical examples are the tinoxide based sensors for combustible gases ("Taguchi or Figaro sensors") used in e.g. gas alarms and the so called A,-sond (based on zirconia) used to control the combustion in cars. 

In this section orrly conductometric sensors are discussed in which the ionic conductivity of the material plays a role. An example includes TiO, which exhibits a variable stoichiometry as a function of the oxygen pressme. Semiconductor materials, like SnOj or similar ones used in Figaro sensors for analysis of reducing species, work on principles of heterogeneous catalysis, without exhibiting ionic conduction in the bulk of the material, and therefore are not considered here. - ... 

CO Resistive sensors pellistors, metal-oxide sensors Optical sensors micro-spectrometer, IR-sources, IR-detectors, IR-filters Hybrid or integrated, surface micromachining Sn02 sintered thick film (Figaro, FIS,. ..), Sn02 thin and thick film on silicon (MiCS, Microsens) IR spectroscopy (Vaisala, Honeywell,. ..)... 

Measurement and Analysis of Adsistor and Figaro Gas Sensors Used for Underground Storage Tank Leak Detection... 

TGS 825 sensor (Figaro Inc.) in the presence of toluene vapor is presented along with a regression model determined by linear least squares using a log... 

Schematic diagrams of commercial tin oxide sensors by Figaro Engineering Inc. are shown in figure 14.2. The sensor of figure 14.2(c) consists of a small ceramic tube coated with tin (IV) oxide and a suitable catalyst. A heater coil maintains the tin oxide temperature (between 200 and 500 °C). The signal is the resistance measurement between the two electrodes at opposite ends of the tube. The assembly is packaged in a protective housing with an open area (covered by wire mesh) to allow gases to enter.

Power consumption for these Figaro-type sensors ranges from 0.6 to 1.2 W. In one effort to reduce the power consumption, Figaro devised a pulse-driven sensor... 

Figaro literature [4] cautions that their TGSs (tin dioxide gas sensors) are... 

In consumer s use, applications of gas sensors related to environmental pollutant gases are carried out mainly for security and amenity. Examples of the applications are, for instance, in the protection from a incomplete burning of combustion apparatus for home use and in the ventilation or condition of indoor atmosphere. A combustion monitoring sensor using SnOj was developed by Tanaka et al.[110] of Figaro Engineering, Japan. The gas water-heater... 

Fig. 8.2. Example of time evolution of 6 tin oxide gas sensors (Figaro S sensors) in the ambience of a composting plant...

Figure 8.4 shows drift compensation of a commercial tin oxide sensor (TGS2620, Figaro ) by multiplicative factor estimated from calibration measurements in ethanol. 

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