Application of the piezo resistivity model to estimate valence and conduction bands shifts induced by the mechanical stress is presented. Parameters of the silicon pressure and acceleration sensor, which are under development in the ITE, Warsaw, were used. Geometrical and technological data were used in calculations of the silicon energy band structure and longitudinal coefficient of the piezo resistivity.(pi) _L.

This paper describes the design, technology aspects and exploitation parameters of thick film pressure sensors manufactured in LTCC technology.

The work discusses the application potentials of sol-gel technique in the technology of planar waveguide sensor. The capability to form refractive profiles with the use of various techniques applied in planar optics have been compared. The authors present the results of investigation studies involving the application of sol-gel technique of the oxide system SiO₂:TiO₂ for the formation of sensor layers, mask layers and waveguide layers. The influence of the thickness of waveguide layer and of its refractive index on the sensitivity of the meter measuring the refractive index changes an working in the difference interferometer system has been investigated.

Optical time-resolved spectroscopy using optical fibers opens up new possibilities for research on highly scattering materials. We present a system that measures the time of fligh distribution of light propagating through such materials. The system employs a picosecond semiconductor laser, a photon counter using an avalanche photodiode working in Geiger mode and standard, gradient index profile, multimode fibers. We present the results of measurements obtained using this system and conclusions regarding the further improvement of the system.

The results on the use of technology of rheotaxial growth and thermal oxidation to p0repare sensory layer of stannic oxide are present in this study. Sensor properties of the SnO₂ layers greatly depend on a stage of tin layer rheotaxial growth. Observations of tin layer surface made after the process of rheotaxial growth and the SnO₂ surface on the oxidation stage performed by means of a scanning electron microscope permitted drawing of many substantial conclusions regarding technology of production. The worked out technology made it possible to form sensor structures, which were next measured. This study provides a fragment of a wide research project over preparation and characterization of thin sensory layers made from stannic oxide and accomplished at the Institute of Physics and Institute of Electronics, Silesian Technical University.

The reported back-side contact sensor were fabricated using a standard IC technology. The silver/silver chloride layers were deposited using electrochemical technique. The sensor chips were passivated with silicon nitride layer deposited by LPCVD, which ensure the stability of measurements. Preliminary examination of prepared sensor included the evaluation of their electrical properties and potentiometric response toward chloride. It was found that 19 sensors among 20 exhibited fast and reversible response toward chloride. Near theoretical slopes were obtained over the 10^-4- 10^-1 M chloride concentration range. The response time was shorter than 10S. The statistical evaluation, the calibration curves and the dynamic response of 20 sensors tested at the same time indicates that the proposed technology ensures preparation of sensor chips in a very reproducible way.

This paper presents studies concerning the optimization of PVC nitrate-selection membranes based on quaternary ammonium salts. Performances and selectivities of chemically modified field effect transistors based on the studied polymer membranes were tested. The influence of concentration and of the structure of the quaternary ammonium salts on the PVC membrane selectivity was investigated. The dependence of properties of the membrane on the polarity of the plasticizer used in membranes was also studied. The highest nitrate selectivity and almost theoretical response were obtained for o-NPOE/PVC membranes containing 1 percent of symmetrical tetradodecylammonium nitrate or tetradeclyammonium bromide.

We review the principles of optical sensor based on the use of the sol-gel technique, in particular their fabrication. We also report on potential applications of the recognition phases prepared by encapsulation of fluorescent chemosensors which have been designed by means of a supramolecular approach: two anthryl groups linked to diaminodiethero group. Occurrence of the metal ion-receptor interaction is signaled through the enhancement of anthryl fluorescence. The enhancement takes place when the receptor is able to promote a photoinduced electron transfer mechanism. Cu(II) ions can be distinguished form other transition metal ions in aqueous solution by the recognition phase.

The paper present detailed spectrophotometric studies of thermochromic and solvatochromic properties of solutions of cobalt chloride. The solution exhibits absorbance changes in the visible spectrum in dependence of the temperature and polarity of the solvent used. The influence of the solvent structure, alcohol/water ratio on the spectral properties of the thermochromic solution was examined. The results obtained can be useful in the design of the receptor part of the temperature and humidity fiber optic sensors.

In this paper the rational description of the sensor constructed to detect the flow reversal has been presented. The sensor consists of two parallel heated wires the distance between them is appointed in such a manner that the thermal interaction of wires may be observed. In the sensor the wires are connected in series, and they are supplied by one constant temperature system. Consequently, the sum of resistances of wires is maintained to be constant. The difference of voltages referring to heated wires is recorded.

A new method of contour and its characteristic feature extraction form noisy image is presented. For image smoothing, the image convolution with a Gaussian function has been used. Then an inflexion point of an image function in the direction of the image gradient vector has been used as a new contour definition. Behavior of this image gradient gives also the information about spatial orientation of contour segments used as invariant characteristic features. Thus, the angles between segments have been calculated by means of operations on the histogram of contour angles. The method application on a highly noised image has been used for illustration of proper method works.

The present paper deals with technologically advanced, programmable, intelligent transceiver for the wireless measurement of the strain, static and dynamic stresses and forces using the strain gauges. The intelligence of the measurement modules enables the long time operation. The system zero-scale calibration, span and offset limits can be set remotely. Digital filters are used for the optimum frequency response of the measuring signal. The transceiver is also equipped with the input for the latest generation of the Dallas digital temperature sensors.

This paper presents a new wireless measurement method for static and dynamic examination of buildings, bridges, masts, towers, steel structures, silos etc. by using new generation telemetric modules operating in intelligent radio network. The system provides a possibility of steel and reinforced concrete structures evaluation by measurement of mechanical stresses, deformation and temperature - depending on used sensor. Developed and built prototype system can be used for the on line monitoring, quality assessment and the usefulness of the building objects over long time periods.

This paper present the concept of the transducer for shape reconstruction and magnetic induction measurement of periodic arbitrary shape wave magnetic field. The measuring head consists of three coils with separated leads. Coils are fixed perpendicularly one to the other. Coil output voltages are synchronously sampled and the input samples are processed according to the algorithm developed. The characteristic curve of the transducer is theoretically deduced. Algorithm fixing signs of currently reproduced output samples of reconstructed shape wave is commented. Most significant uncertainty sources of the circuit thrust by essential blocks of signal processing path are analyzed. It was confirmed by simulation that the reconstructed wave shape and calculated induction value are independent of angle setting of measuring head in magnetic field. The transducer sensitivity to the angle setting in the magnetic field is very small.

A construction and metrological properties of 'two- temperature' humidity generator KW-2 are presented in the paper. Changes in humidity are obtained by changing the temperature of moist air, for which exact dew point is obtained in saturator. The calibrator has ability to ensure relative humidity from 5 percent RH up to 100 percent in wide range of temperatures and with a good accuracy. It makes possible not only usual calibration of humidity sensors but also testing of sensors temperature characteristics. Important advantages of the calibrator are simple and cheap design and low operating cost.

The main aim of this work is to present an application of PIC16 microcontrollers in single sensor two gas - CO and CH₄ detectors, using recently developed by FIS Incorporated, semiconductor sensor SB-95. Microcontroller is used not only for comparison the actual output signal from the sensor with the warning and alarm thresholds, but also provides control and self diagnostic functions. Output logic signals allow user to check the level of gas concentration and detect the improper operation of sensor and electronics circuits.

Two new methods of sub-cooled water recognition in dew point hygrometers are presented in this paper. The first one- impedance method use a new semiconductor mirror in which the dew point detector, the thermometer and the heaters were integrated all together. The second one an optical method based on a multi-section optical detector is discussed in the report. Experimental results of both methods are shown. New types of dew pont hydrometers of ability to recognized sub-cooled water were proposed.

In this paper we describe an idea of a multiband system for non-contact temperature measurement and analytic techniques which allow calculate temperature and emissivity of the examined body from the measured data. Influence of some factors on measurement accuracy is discussed. Described technique gives a possibility to optimize construction of the whole system.

In this paper two models of eddy current sensor have been presented. They are base don a one- and multi-turn coil model. The results of computer simulations present a relation of eddy current density on nonferromagnetic conducting materials versus some parameters viz: a coil radius, frequency of excitation current and conductivity of material.

Hot-wire measurements in non-isothermal flows require temperature compensation or correction. One of solutions is the system of two hot-wire anemometers which enable to measure velocity and temperature in non-isothermal gas flows. The output signal come from two hot-wire anemometers operating at different overheat ratio. As the two sensors operate in a CTA mode, we get a wide range of frequency bandwidth for velocity and temperature measurements. This paper present the result of modeling and optimization of a double hot-wire anemometer system providing temperature correction of anemometric signal.

This paper deals with a numerical modeling and optimization of a piezoresistive silicon pressure senor with an etched membrane and diffused piezo resistors. The mentioned sensor utilizes resistance changes of piezo resistors placed on the stressed membrane. Th stress is induced by the differential pressure applied to the membrane. Presented numerical modeling of the pressure sensor was based on theory of piezo resistivity and finite element modeling (FEM). Theory of piezoresistivity allowed for calculating the resistance changes of piezo resistors while FEM allowed for calculating the stress distribution. Applied modeling procedure provided a direct insight into an output signal of the sensor under loading. The main problem of numerical modeling is an accuracy of the achieved results. Because of our reduced knowledge on physical phenomena's, material properties and inherent inaccuracy of numerical methods nay engineer should be aware of the limited accuracy of numerical modeling. There are a number of methods that allow at least to assess roughly the error of modeling but there is still a lot of work to do. Therefore it is the rule of thumb that results of modeling should be always verified with the experiment whenever it is possible.

This paper describes the measurement system used for measuring properties of the ion selective electrodes and for multi parameter measurement. The measurement system can be used for research of dynamic properties of the ion selective electrodes and electrode arrays.

A non-contact passive inductive interface to any type of capacitive sensor structure is presented in the paper. The interface performance is based on the magnetic coupling between two planar coils where one is located on the sensor die and the other is the pat of measurement circuit. The interface construction ins very simple in fabrication and reliable in operation. The theoretical calculations, metrological parameters analysis as well as a sensitivity on the interface parameters variation are discussed in the report.

The present paper deals with theoretical basis of coulometric method used for measurement of chloride ions concentration in water solutions. Static transfer equations were derivated for generator electrodes circuit, as well as for equation describing the kinetics of phenomena taking place in detector electrodes circuit. Basing on assumptions resulting from mathematical models, chloride ions concentration meter was designed and built. This model was used for experimental verification of derivated transfer equations. Results of performed measurements and their analysis confirmed presented theoretical considerations.

This article presents results of a theoretical and simulating analysis of the accuracy of the method of the direct measurement of resistance using a charge balancing circuit and the 'autozero' method. Achieved results showed that those construction makes it possible to reduce a majority of factors that could be sources of measurement errors, however an extent of the reduction first of all depends on parameters of the used semiconductor switches. The influence of finite values of on-state resistances and switching times on a linearity and monotonicity of the conversion characteristic were analyzed in the paper. Results of simulations have been based on parameters of contemporary MOSFET transistors that can be used to switch currents in the circuit.

The simulation results of temperature distribution in the new type silicon dew point detector are presented in this paper. Calculations were done with use of the SMACEF simulation program. Fabricated structures, apart from the impedance detector used to the dew point detection, contained the resistive four terminal thermometer and two heaters. Two detector structures, the first one located on the silicon membrane and the second one placed on the bulk materials were compared in this paper.

The FFT makes a powerful tool for analyzing signals in numerous measurement applications. The present paper deals with several problems concerning the application of the Fourier series analysis in the case when a fluctuating value of a measureand is converted into a frequency signal i.e. when instantaneous frequency of a pulse signal represents an instantaneous value of the measured quantity.

New applications for avalanche photodiodes (APDs) as in systems using visible radiation, have prompted the need for the evaluation of detection properties of ITE APDs in the 400 divided by 700 nm spectral range. The paper presents the method and result of studies on the spectral dependence of the gain, dark and noise currents, sensitivity and excess noise factor of ITE APDs. The studies have shown that ITE APDs optimized for the near IR radiation can be effectively applied in the detection of radiation above the 500 nm wavelength.

The paper presents the results of studies on temperature dependence of such parameters as a dark current, noise current, gain, noise equivalent power and detectivity of silicon epiplanar avalanche photodiodes at the ITE. The photodiode reach-through structure is of an n^PLU-p-(pi) - p⁺ type with an under-contact ring and a channel stopper. The temperature range was stretching from -40 C to +40 C. Specially developed for this purpose an automatic system for low noise measurements was used. A two- stage micro-cooler with a Peltier's element was applied to control and stabilize the temperature of measured structures.

This paper presents works over correlation between parameters of domain structure and pyroelectric current in IR sensors base on TGS doped with amino acid-lysine was grown. Computer measuring system making possible registration of domain structure images of non-linear dielectrics was designed and executed. We worked out measuring and analysis algorithms of domain images. Software making possible calculations and analysis of parameters of observed structures was created and static measurements of domain structure within different growth pyramids were performed. Correlation between parameters of domain structure, quantity of admixture and temperature characteristics of pyroelectric coefficient was found.

In this paper the results of the experimental investigation of fiber optic electric field intensity sensor are presented. These sensors are based on electroluminescent effect which consists in the light emission by some substances placed in variable electric field. The luminescent effect is observed in some composite semiconductors, among other - ZnS, doped by Mn, for high its concentration, order 10^-4 - 10^-3 g/g. The final aim of this investigation will be the elaboration of an electric intensity sensor, which together fiber optic temperature sensor and intensive of magnetic field sensor make possible, in the future, to monitor the state of work of electromagnetic power arrangements, first of all - high voltage power transformers.

The results of work on design and technology of a novel fiber-optic sensor are presented. It contains an avalanche photodiode of the 1.55 mm diameter active area coupled with a scintillating plastic fiber of the 1 mm diameter. This fiber emits the light of 530 nm wavelength as a result of interaction with ionizing particles. The developed technique of assembling not only have ensured high optical coupling between the fiber and photodiode structure but also secured total isolation of the photodiode against background radiation. The described sensor design ensures better isolation of an avalanche photodiode structure against nuclear radiation than the sensor with scintillating wafer directly attached to the active surface of the structure.

The paper presents theoretical analysis of planar optical waveguide of the chemical sensor with amplitude modulation. The analysis of the investigated structure is focused on refractive profiles made using ion exchange in glass as well as on the parameters of sensor layer made using sol-gel technique. The influence of waveguide parameters, sensor layer parameters and refractive index of the environment on attenuation coefficients of the guided modes are considered. For the theoretical analysis of the investigated structures the Vassell's matrix method has been used.

The paper presents the fabrication technology of planar gradient tapered waveguide structures using the ion exchange technique in glass. Theoretical predictions of model properties have been compared with experimental results. Application possibilities of these waveguides in sensor related techniques have also been pointed.

In the paper are presented numerical studies of gradient index optical splitters made in a multimode interference technology by Ag⁺ $ARLR Na⁺ ion exchange process. The influence of geometrical parameters of multimode interference structure and technological process parameters is examined in numerical simulations and gradient index optical waveguide splitters and Mach-Zehnder interferometers are proposed. The possibility of using MMI sections as transducers of distributed sensors is discussed.

In the paper are presented investigation of planar and channel polarimetric interferometer made by ion exchange in glass for sensor applications. J have determined the dependence of the difference of propagation constants of orthogonal modes of the same order on the refractive index of the cover, for planar waveguides obtained during the ion exchange K⁺-Na⁺ in the glass BK-7. Similar measurements have been made for the exchange Ag^PLU- Na⁺, determining also for that case the influence of heating time on those parameters.

The paper includes presentation of gas detection sensor used in Polish mining industry of gassy mines. Sensor of explosive gases and those of toxic gases are especially taken into consideration.

A gas analyzer based on chromatography method using silicon- glass components has been built. Its main components were made by using MAMS-like technology, and its conception is concurrent to the idea of an integrated silicon chromatography proposed by SC Terry.

The paper describes the microsystems for total chemical analysis and the structure of a gas microchromatograph. The construction and technical data of capillary micro column of thermo conducting detector and gas microvalve are also described. The paper refers to the test of a model of gas micro chromatography, the analyses of gas samples and presents the exemplary chromatograms.

Carbon-in-ash level is an important consideration for combustion efficiency as well as ash marketing. The optoelectronic analyzing system for on-line determination and monitoring of the u burned carbon content of ash samples is presented. The apparatus operates on the principle that carbon content is proportional to the reflectance of IR light. Ash samples are collected iso kinetically from the flue gas duct and placed in a sample tube with a flat glass bottom. The same is then exposed to a light. The reflectance intensity is used by the system's computer to determine residual carbon content from correlation curves. The sample is then air purged back to the duct or to the attached sample canister to enable laboratory check analysis. The total cycle time takes between 5 and 10 minutes. Real time result of carbon content with accuracy 0.3-0.7 percent are reported and can be used for boiler controlling.

Flame instabilities, which can occur during firing up an of industrial boiler, may point to improper fuel/air ratio or boiler malfunction. It can be detected as sudden variations of amplitude of the output signal, obtained from the fiber- optic flame monitoring system. Because of unstable character of this signal, wavelet transform has been chosen as an investigative instrument.

The evolution of photoelectric converter, fiber optics and integrated circuits, in particular optic detectors, increases area of applying of the industrial measuring and control systems that used IR detectors. One of the more important is optic detection of electric arc in industrial energetic arrangements. That kind of detection is sure, easy to apply in existing industrial apparatus a d it is cheaper than another way of detection. Additionally optic detection of electric arc is safety for attendance persons and may work on computer system. The article presents an example of circuit with semiconductor IR photoelectric detector to detection of electric arc and points at the most important questions which should be taken into consideration in designing instruments like described one.

The output signal of the thermal converter should be insensitive to ambient temperature changes. In practice, however, a thermal converter always features a nonzero temperature coefficient of the output signal. This coefficient is determined mainly by the dependence of the heat transfer process on the ambient temperature. The main goal of this paper is to analyze the effect of different enclosures on particular and total temperature coefficients. Three types of enclosure are considered: high-volume enclosure filled with a ga sat pressure close to the atmospheric, low-volume enclosure filled with a gas at pressure close to the atmospheric and low-volume partially evacuated enclosure at internal pressure of some 1 X 10^-4 Pa. The analytical expression for both the thermal conductances and their corresponding temperature coefficients are presented. Example numerical results for a prototype of the converter are also included.

Typical single-chip CCD co0lor camera provides output signal containing RGB components of acquired image. Strong inter- channel correlation of that signal, unacceptable for some applications, is shown. Therefore, some kind of RGB color space transform is required to decrease this correlation. Only the Karhunen-Loeve transform (KLT) secures compete decorrelation. However, possible applications of this method are limited by the fact that coefficients of transform matrix must be calculated for each image separately. In the paper details of effective implementation such transform of color images are described. The examples of KLT applications in the field of color image processing are quoted. Using the standard color images, principal properties of KLT are shown, i.e. a complete decorrelation of color components and energy compaction in first components. This paper present also an approach that allows determining KLT coefficients that are constant for certain class of images and guarantee complete decorrelation simultaneously. A methodology for finding these coefficients is briefly described and some remarks on criteria of image selection for this class are made.

Spectrophotometric methods provide many new possibilities of investigation of combustion process in the automotive engine with spark ignition. Emission spectrum of the flames from the combustion chamber provides valuable information, which is difficult or even not accessible with the aid of other measurement methods. Spectral analysis allows to evaluate concentration of active compounds present in flames, which do not constitute final products of combustion. Concentration of radicals depends on some combustion parameters such as air-fuel ratio. The paper describes an engine test stand equipped with fiber-optic measurement system. The measurement system consists of an optical sensor mounted in the engine head, fiber-optic bundle for signal transmission, grating monochromator and photodetector. Voltage signal from the photodetector is recorded by the PC- based data acquisition system. The main aim of research was to verify usability of the designed fiber-optic measurement system in combustion diagnosis and to develop a method of evaluation of the air-fuel ratio on the base of simplified spectral analysis of the emission during combustion process in an automotive gasoline engine.

Wavelet analysis was used for detection of abrupt changes in sensors signal. The ability to isolate the effect of noise and process changes from analyzing signal was shown, therefore rapid changes due to sensor fault can be magnify through high frequency wavelet coefficients. Wavelet analysis was also used for P phase time arrival identification in one component seismograms form coal mine tremor stations.

Under etching of convex corners during the fabrication process of pressure sensor with the 'bossed' type structure seriously deteriorates parameters of these devices. The problem can be solved by application of properly designed masks with compensating corners.