Film sensor

Because of its small size and portabiHty, the hot-wire anemometer is ideally suited to measure gas velocities either continuously or on a troubleshooting basis in systems where excess pressure drop cannot be tolerated. Furnaces, smokestacks, electrostatic precipitators, and air ducts are typical areas of appHcation. Its fast response to velocity or temperature fluctuations in the surrounding gas makes it particularly useful in studying the turbulence characteristics and rapidity of mixing in gas streams. The constant current mode of operation has a wide frequency response and relatively lower noise level, provided a sufficiently small wire can be used. Where a more mgged wire is required, the constant temperature mode is employed because of its insensitivity to sensor heat capacity. In Hquids, hot-film sensors are employed instead of wires. The sensor consists of a thin metallic film mounted on the surface of a thermally and electrically insulated probe. 

Golovanov, V., J. L. Solis, V. [.antto, and S. Leppavnori. Different Thick-Film Methods in Prinr-mg ot one-Electrode. Semiconductor Gas Sensors. Sensors Actuators B34 (1996), pp. 410-416. Lantto, V., and V. Golovanov. A Comparison of Conductance Behaviour between SnO> and CdS Gas-Sensitive Films, Sensors Actuators B24-25 (1995), pp. 614-618. 

Schubert J, Schdning MJ, Schmidt C, Siegert M, Mesters St, Zander W, Kordos P, Liith H, Legin A, Mourzina YG, Seleznev B, Vlasov YG (1999) Chalcogenide-based thin film sensors prepared by pulsed laser deposition technique. Appl Phys A Mater Sci Process 69 803-805... 

Reactor type Chip reactor with thin-film sensors and membrane Catalyst material Pt... 

Fig.4.1. Dependence of the concentration of free CH3 radicals in a quartz cylindrical cell on the distance between the film sensor and the point where the radicals are produced, for different temperatures of the vessel walls 25 C (/), 140 C (2), 24rC O), 269 C (4), and 300 C (5).

Fig.4.3. Experimental arrangement for investigation of pyrolysis of molecules by the method of semiconductor sensors 1 - reaction vessel, 2 - quartz slab with a ZnO film (sensor), 3 - filter, 4 - contacts, 5 - incandescent filament, 6 - thermocouple, 7 - cell with a substance, 8 - lamp - manometer, 9 - pin, 10 - flask, 11 - sealing bulkhead, 12 - trap, 13 - thermostat.

Volume 1 Thick Film Sensors (edited by M. Prudenziati)... 

When the development of a scientific field expands, the need for handbooks arises, wherein the information that appeared earlier in journals and conference proceedings is systematically and selectively presented. The sensor and actuator Held is now in this position. For this reason, Elsevier Science took the initiative to develop a series of handbooks with the name "Handbook of Sensors and Actuators" which will contain the most meaningful background material that is important for the sensor and actuator field. Titles like Fundamentals of Transducers, Thick Film Sensors, Magnetic Sensors, Micromachining, Piezoelectric Crystal Sensors, Robot Sensors and Intelligent Sensors will be part of this series. 

Ohba, K., T. Origuchi, and Y. Shimanaka, 1984, Multi-Fiber Optic Liquid Film Sensor, Proc. 4th Sensor Symp., pp. 33-37. (3)... 

Mills A., Chang Q., McMurray N., Equilibrium studies on colorimetric plastic film sensors for carbon dioxide, Anal. Chem. 1992 64, 1383. 

Choi J.W., Bae J.Y., Min J., Cho K.S., Lee W.H., Fiber-optic ethanol sensor using alcohol dehydrogenase-immobilized Langmuir-Blodgett film, Sensor Mater. 1996 8 493-504. 

A new generation of detectors has been developed with NbSi thin-film sensors (instead of the NTD sensors for present detectors). Each detector consists of a Ge crystal with two NbSi sensors acting also as electrodes for charge collection. These thin-film sensors are sensitive to the athermal component of the phonon signal, acting as near-surface interaction tag [49],... 

Platinum thin-film sensors are available in a broad variety of forms. Depending on the proposed application, the sensor may be unhoused, encapsulated in ceramic, configured as a surface mounted device (SMD) or located within a plastic housing with rigid pins. An overview of the variety of different forms currently available is given below (Fig. 5.2). 

Even conventional hotplates can be fitted with a continuously variable temperature control thanks to platinum thin-film sensors. The encapsulated platinum sensor is positioned so that it is in contact with the cast iron plate from below and thus able to register the temperature of the hotplate. Normally the power supplied to the plate is regulated by a stage switch. The increased control sensitivity is made possible by incorporating electronic circuitry capable of interpreting and acting upon the sensor signals. 

The results suggest SSTTXs as new sensor elements for glycoside, pharmaceutical, prostaglandin and steroid sensors. Indeed, a 2 pm thick film sensor (i) provides 0.3 pM detection limits for 9-anthrol (ii) yields a 45 s response time and (iii) is completely reversible (6% relative... 

M. Stankova, X. Vilanova, E. Llobet, J. Calderer, C. Bittencourt, J. J. Pireaux, and X. Correig, Influence of the annealing and operating temperatures on the gas-sensing properties of rf sputtered WO3 thin-film sensors. Sensors Actuators 105(2), 271—277 (2005). 

A. Heilig, N. Birsan, U. Weimar, M. Schweizer-Berberich, J.W. Gardner, and W. Gopel. Gas identification by modulating temperatm-es of Sn02-based thick film sensors . Sensors and Actuators B43 (1997), 45-51. 

S. Hahn. Sn02 thick film sensors at ultimate limits Performance at low O2 and H2O concentrations Size reduction by CMOS technology, Ph.D. thesis. University of Tubingen, Germany (2002). 

Sadagopan K, Sawant SN, Kulshreshtha SK, Jarori GK. Physical and chemical characterization of enolase immobilized polydiacetylene Irangmuir-Blodgett film. Sensors Actual B 2006 115 526-533. 

The potentiometric determination of bromide anions with ion-selective electrodes is possible with commercial electrodes that are commonly based on solid Ag2S—AgBr ion conductor membranes [148-150]. Recently, a novel liquid film sensor has been proposed by Ganjali etal. [151] Determination of bromide was reliable without significant interference from common ions such as chloride and iodide, and was reported down to a micromolar level. The electroactive species in the liquid membrane... 

Physical State Evolved Gas Analysis Mass spectrometer Gas chromatography IR transmission Film sensors External sample analysis... 

L. Ping and P. K. Dasgupta, Determination of Total Mercury in Water and Urine by a Gold Film Sensor Following Fenton s Reagent Digestion, Anal. Chem. 1989,61, 1230. 

Fig. 8.5 Thin Au film sensor for mercury vapor and other adsorbing species...

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