Sensors technology

The Passive sensors acquire energy from an external source, e.g., the Sun, and for Active the energy is generated from within the sensor system, beamed ontward, and the fraction returned is measured. Other types of commonly deployed sensors in remote sensing studies are as follows  

Radiometer is an instrument that quantitatively measures the EM radiation in some interval of the EM spectrum. 

Spectrometer is an instrument with a component, such as a prism or diffraction grating, which can break radiation extending over a part of the spectrum into discrete wavelengths and/or separate them. 

The term spectroradiometer tends to imply that the dispersed radiation is in bands rather than discrete wavelengths. Most of the remote sensing satellites have spectroradiometers on board. 

Sensors that instantaneously measure radiation coming from the entire scene at once are called framing systems, i.e., eye, camera, and TV. The size of the scene that is framed is determined by the apertures and optics in the system defines the field of view. 

Patterned copper tracks can be deposited on a flexible PI film. The devices can be used for electronic appUcations. 

With a conventional desktop ink-jet printer an aqueous palladium(II) solution is sprayed onto a surface-treated PI film. The palladium(II) is then reduced by treatment with sodium borohydride (NaBH ). Finally, a copper layer is deposited by electroless copper plating. The surface treatment of the PI, in order to accept the palladium(II) consists either of oxidation with alkaline KMNO4 at 80°C for 60 min or simply with NaOH at room temperature for 72 h. The latter treatment gives better results. Structures with dimensions down to 100 jum with good copper adhesion can be built. 

In a similar way, gold pattern layers have been put on PI substrates by micro contact printing. In micro contact printing, a polymeric stamp that is wetted with a potassium hydroxide solution is pressed onto the PI substrate. The alkaline treated regions of the substrate become hydrophilic and are prone to hold a palladium(II) solution. In the same way as described above, the adhered palladium ions are reduced by NaBILj and further electroplated. 

Flexible PI electrode microelectrode arrays have been developed for electric potential probing for in vivo applications. Implantable micro- 

On the basis of these observations, the Military Munitions Waste Working Group believes that the efficiency and cost-effectiveness of 

---

Committee on New Sensor Technologies Materials and Applications, National Materials Advisory Board, Commission on Engiueeriug and Technical Systems, National Kesearch Council Keport Expanding the Vision of Sensor Materials, National Academy Press, Washiagton, D.C. 1995, pp. 33-45. 

Fig. 16. Exploded view of a smart transmitter based on variable capacitance sensor technology.

Technology has been introduced for on-line estimation of the kappa number based on absorption of ultraviolet light (35). This breakthrough ia optical sensor technology permits closed-loop feedback control of digesters from on-line measurement of the kappa number. 

These results have demonstrated that the biomimetic approach of copying the supramolecular principle of archaeal cell envelopes opens new possibilities for exploiting functional hpid membranes at meso- and macroscopic scales. Moreover, this technology has the potential to initiate a broad spectrum of developments in such areas as sensor technology, diagnostics, biotechnology, and electronic or optical devices. 

Kriz, D Ramstrom, O Mosbach, K, Molecular Imprinting, New Possibilities for Sensor Technology, Analytical Chemistry June 1, 345A, 1997. 

This demand for new devices initiated worldwide research and development programs in the field of "sensors and actuators". Many generic sensor technologies were examined, from which the thin- and thick-film, glass fiber, metal oxides, polymers, quartz and silicon technologies are the most prominent. 

Richard L. Rowe is retired chief executive officer of MCMS, Inc., a 550 million electronics contract manufacturing company. His experience includes sensor technologies applied to aviation security, and his expertise includes new technologies in optics and radio frequency, electronic sensors, and switch products. He has more than 20 years of experience in the electronic sensors and switch products in-... 

Guizard, C., Bac, A., Barboiu, M. and Hovnanian, N. (2001) Hybrid organic-inorganic membranes with specific transport properties. Applications in separation and sensors technologies. Separation and Purification Technology, 25, 167-180. 

Table 1. Fundamental Contributions to Optical Oxygen Sensor Technology up to the Year 2000 (only main author/s given).

As stated above, the beginning of optical pH sensor technology remains hidden. What is nowadays refered to as a sensor layer was formerly mostly refered to as a test strip, a dry reagent chemistry, or an immobilized reagent. 

Other medical products based on optical sensor technology include those of Cardiomed (System 4000), Puritan-Bennett, and one of Radiometer (Copenhagen) which has been withdrawn meanwhile. Optical (but non-fiber) sensors for oxygen and for C02 also are widely used for the determination of bacteria in blood. In 1986, Gehrich et al.36 described an optical fluorescence... 

Sensing schemes have become reliable enough to be of practical utility, instrumentation has become available at costs that make this sensor technology competitive to established sensors, and numerous other sensors schemes have been presented that are of interest, at least from an academic point of view. 

Giallorenzi T.G., Bucaro J.A., Dandridge A., Sigel G.H., Cole J.H., Rashleigh S.C., Priest R.G., Optical fiber sensor technology, IEEE J. Quant. Elect. 1982 QE18 626. 

K.T.V. Grattan, Fibre optic sensor technology, Sensors Actuators A 2000 82 40-61. 

Grattan K.T.V., Meggitt B.T., Optical fiber sensor technology, Vol.4 Chemical and environmental sensing, Kluwer Academic Publishers, 1999, pp. 205-248. 

Faculty of Mechanical Engineering, Centre of Sensor Technology, University ofMaribor Smetanova 17, SI-2000 Maribor, Slovenia... 

Among the great variety of organic chromophores such as azo dyes, nitrophenols, phthaleins, sulfophthaleins, aniline-sulfophthaleins, triphenylmethane dyes, polymethines, and others, only a few have so far been considered to be useful and applied to sensor technology (Table l)25 34. Important characterization parameter of pH indicator is its pKa value ... 

---