The aim of the paper is to present polarization characteristics of the light scattered on single fibers and an ensemble of infinitely long cylinders modeling a real composite material. The presented simulation investigations regarding multiple scattering phenomena have been done with the use of Lorenz-Mie theory and Monte Carlo method.

The principle work of different types of distributed fiber optic sensors is presented. We treat fiber sensor as a long line end define it input impedance. The parameters of the impedance determine the principle work fiber sensors. Each method enables the place of disturbance localization.

The paper presents possibility of the application of electroluminescent effect to the construction of electric field intensity sensors. Electroluminophores for these sensors were elaborated on the base of II-VI group semiconductors. Using ZnS:Mn and ZnS:Cu electroluminophors the fiber optic intensity of electric field sensors were prepared. The presented sensors belong to the group of intensity sensors. The advantages of fiber optic electric intensity sensors allow to apply them in various industrial electric power machines.

The paper presents the results of research on the influence of long-term heating of planar waveguides at a low temperature (427 K), produced as result of ion-exchange K⁺--Na⁺ and Ag⁺--Na⁺ in chosen types of glasses, on their properties. The changes in the maximum value of a refractive index on the waveguide surfaces as well as diffusion constants for tested types of glasses at heating temperature were defined.

The subject of this paper is a system for measuring thickness of opaque dielectric layers using the change of the coefficient of the magnetic coupling of two coils. This circuit was designed for measurements of thickness of elements in boats made from epoxy-glass laminates. It can, however, be used everywhere, where the need occurs to make non-destructive thickness measurements of dielectric layers in the range from 5 to 30 mm with an accuracy of 0,5 mm.

The results of the investigation and theoretical analysis of the simple pneumatic sensor's dynamics in conditions of the step-changed length of the detail are presented. The mathematical model taking into account actual losses of the flow and adiabatic changes of the air in the measuring chamber was worked out. For the sensors with inlet and measuring nozzles d_w and d_p from 1 to 2 mm and the volume of the measuring chamber V_k equals 4 cm³ the setting time t_0,95 is 12 to 45 ms, that enables to apply these sensors in the preventive inspection systems.

In this paper, an optical scanner which can be used to investigate a 3D space, has been presented. Some main applications of that device, have been described. The diagram scheme of the scanner as well as a principle of operation and design of particular functional parts are shown. Major tasks of the software which is built in a controller and cooperates with the scanner, are presented. The methods on how create a geometrical model of environment to be useful for navigation of mobile robot, have been discussed. Some results of experiments are given.

The paper presents the method of localization the disturbance place in fiber optic distributed sensor. Furthermore the present writers propose the system composed of Sagnac interferometer coupled with balanced Mach-Zehnder interferometer. The experimental system was constructed and precision of the localization estimated.

The paper gives an amplitude-frequency-time analysis of acoustic signals caused by breaking window-panes and some selected signals received from the environment. The analysis made it possible to determine the excitations which should set off an alarm in the case of shattering the window-pane. It enabled to determine the algorithm of converting the signal from the microphone and the realization of the microsystem cooperating with it. The algorithm is based on an amplitude analysis of signals in two frequency intervals and their time sequence. The microsystem is provided with two selective channels where the amplitude analysis is possible by making use of comparators. The time analysis of the sequence of events being registered is carried out in an 8-bit COP800 microcontroller produced by National Semiconductor firm.

Uncomplicated structure and low costs have caused an immense increase in the applications of reflective optical fiber sensors. The growing interest demands more precision and reliability from the sensors. At the same time the development of microprocessing resulting in increased computing power and computer speed allows to create and simulate increasingly complex systems or 3D measurement structures. Using these possibilities, the paper presents the results of a computer simulation of a fiber optic reflective structure. Special attention is paid to the effect of deflection changes in the reflective surface and to the diffuse reflection from the analyzed surface.

In order to measure a complicated unsteady 3D subsonic turbomachinery flow field by use of five-hole pressure probes and a multisensor hot-wire probe, a computer aided measurement system was built up and developed. Long experiences acquired by us and by other research institutes in various experimental studies were taken into consideration as measurement rules in the system. Using the present measurement system, the 3D unsteady flow fields in turbumachinery were determined. The automatic measurements were performed satisfactorily even in the downstream rotor flow region. From the experiments, it is concluded that the quality of the measurements of the unsteady 3D flow field behind a rotor is improved greatly by means of the proposed computer aided multisensor system.

Difficulties in construction of pressure transducers working at pressure up to 2 GPa are briefly discussed. Designs and metrological properties of pressure transducer with free active element `bulk-modulus' type with an estimated accuracy better than 0.2% are presented.

An overview of commercial sensors, transducers, monitors and computer systems for arterial pressure and intracranial pressure monitoring has been made in this paper. Similar technical specifications of the devices (measurement range, sensitivity, accuracy) have been emphasized, as well as a variety of structural solutions influencing their static and dynamic parameters. A computer based test stand for checking dynamic properties of pneumatic pressure transducers is presented. It enables tests in a full range of amplitude and frequency change, visualization and comparative analysis of sensor responses for various supply conditions. Exemplary waveforms are shown and initial conclusions concerning sensor features are drawn.

In our laboratory there was elaborated the mode of preparation of side-hole optical fibers characterized by high sensitivity to pressure/sensitivity to temperature ratio. This ratio is two magnitude order higher than this obtained for normal SMPM optical fibers. This work presents the quantitative explanation of this advantageous phenomenon. It has presented the mode and the results of calculations of selectivity to pressure in relation to temperature for defined class of side-hole optical fibers. It has resulted that there exist numerous structures of side-hole fibers for which the sensitivity to pressure/sensitivity to temperature ratio is not lower than 1000. Described mode of calculations of selectivity of birefringent optical fibers to pressure in relation to temperature will permit to optimization of these sensor fibers for technological purposes.

The sensitivity of some resonant and broadband acoustic emission (AE) sensors made of piezoelectric monocrystalline quartz and lithium niobate was investigated under hydrostatic pressures ranging from atmospheric to 1 GPa. Ultrasonic pulses of the 500 kHz frequency generated by an impulse laser were used as the standard AE signals. It was established that the sensitivity of all tested sensors was decreasing with pressure. When measured in dBs the sensitivity of each sensor can be described with a linear function of pressure.

The paper presents a method allowing to reduce the initial offset voltage in piezoresistive sensors. It has been suggested in the work that the number of piezoresistors formed on the surface of the membrane should exceed 4, and the active elements should be selected for the bridge according to the offset minimization criterion during the spike measurements of the structures. A few execution versions of excess piezoresistors have been analyzed, carrying out simulation calculations for each of them to evaluate their performance. In the opinion of the author, the results of the calculations, presented in this tabular and graphic forms, are encouraging. The reduction of the offset voltage entails also the reduction of the temperature zero error. Lower offset and smaller temperature zero error in the crude sensors result in better quality of the sensors after the compensation of errors.

The metrological properties of new ophthalmic tonometer transducer with silicon micromachined structure are presented in the paper. Transducer is dedicated for OPHTHA- Ton tonometer. A principle of dynamic output signal creation in tonometric transducer for intraocular pressure measurement (IOP) during single touch of eyeball cornea has been presented. A test stand developed by the authors for checking metrological properties of transducers as soon as exemplary measurement results have been presented. The results obtained confirm good repeatability of the transducer parameters of IOP measurement and indicate the possibility of applying the transducers for cornea stiffness measurement.

Some alloys specially chosen for their resistivity and low permeability have been investigated in order to detect their utility for force measuring transducer design. The changes of their magnetic characteristic due to the stress applied either parallel or perpendicular to the magnetic flux have been measured. It was found that all of these materials have significant magnetoelastic properties, but one of them (marked 0H23J5) is the best. A new method of presentation of the magnetoelastic effect is proposed. Some designing remarks connected to improvement of metrological properties (sensitivity, linearity, temperature influence) of magnetoelastic force transducers are given.

Local measurement of the coal briquette strains during its destruction caused by sudden decrease of pressure of gas filling pores is difficult, because of high strain of coal (exceeds 16%), which results in bursting. A special type of an resistance-strain gauge, which is pressed into a defined position during briquette preparation was elaborated. This gauge is deformed just as the surrounding coal. The strain is measured as a difference in resistance of a mixture of coal grains (briquette material) and short, 8 micrometers dia. graphite fibers. A ca. 0.5 mm thick and ca. 1 mm long gauge was prepared. Its initial resistance constituted several hundreds ohms. The resistance vs. strain dependence is not linear but stable enough in time and does not depend on the type of gas filling briquette pores (e.g. CO₂ and He).

The subject of this paper is an optical fiber temperature sensor using the techniques of optical time domain reflectometry. The sensor uses the dependence between the refractive index of epoxy resins and temperature and allows us to develop sensors working in transmission as well as in reflective mode.

A method of elimination of the temperature influence on a Liquid Crystal sensor of the electric field based on the temperature measurement and use of a correcting algorithm is presented in the paper. This method results in cost- effective applications, and gives additional information about the temperature in the place where the electric field is measured.

In this paper we present the analysis, design, and construction of a fiber optic evanescent field sensor. A standard PCS multimode fiber was used in a measurement method called the attenuated total reflection. We present sample measurements taken for an alcohol solution of cobalt chloride CoCl₂(DOT)6H₂O compared with the results obtained by methods of classical spectrophotometry. The sensor described can be used in the analysis of strongly absorptive substances, especially where the traditional- optical transmission-measurement methods are impossible.

The present paper discusses theoretical and experimental research on the planar difference interferometer produced with the use of planar technique on a glass substrate plate (planar interferometers) in view of its application in the system of phase-polarization sensors of basic physical quantities.

The fiber optic technique for relative humidity (RH) sensors based on the absorption spectrum of the optical fiber coated with colorimetric reagent cobalt chloride layer is discussed. Probe preparation, optical layout used in the experiment and the responses of the RH probes for different concentrations of cobalt chloride (PVA) solutions are presented.

This paper presents some problems concerned with SAW NO₂ sensors employing copper phthalocyanine (PcCu) as the chemical interface. The influence of piezoelectric substrate materials, crystalline structure and geometry of the PcCu coatings on the sensor sensitivity, and on temperature stability of generated frequency is discussed. The experiments were carried out for SAW delay lines on STX quartz and 128 degree(s)YX lithium niobate. Our measurements concerned PcCu coating of (alpha) and (Beta) structure. We varied the coating layer thickness from 0.1 micrometers to 1.5 micrometers and its density from 0.17 g/cm³ to 1.6 g/cm³. It was found that for the investigated range of parameters the (Beta) -PcCu layer provides several times bettor sensor sensitivity and temperature stability of SAW delay line generation frequency than (alpha) -PcCu layer of the same mass. This is valid for both used substrates.

This paper describes an approach for determining the individual analyte concentrations in a mixture of gases using array tin oxide sensors and cascade correlation learning network. In the present approach a small array of six semiconductor oxide (SnO₂:Pd, Pt) sensors is used to recognize mixtures of air with four pollutants: carbon oxide, methane, propane/butane and methanol vapors. The cascade-correlation algorithm offers a reasonably small net, which is built automatically.

The article refers to the critical analysis of optical system, used in gas analyzers with infrared radiation absorption. To find energy-saving solution, the systems using paraboloids and ellipsoids which cooperate with semi- conducting detector have been considered. The system with ellipsoidal concentrators as more effective in an energy- way, has been the subject to the thorough analysis. For the purpose of compensation of radiation source ageing process and changes in ambient temperature, the three-stage modulation system of infrared radiation has been used. To prove the justness of the solution, the optimal and comparative converter has been constructed and tested.

TiO₂-SnO₂ polycrystalline ceramics were prepared by precipitation from SnCl₄ and impregnation of TiO₂ powder. Thin films were produced by rf reactive sputtering from Ti-Sn metallic target in the Ar+15%O₂ reactive gas mixture. The influence of the system composition on gas sensing performance was investigated. The electrical resistance was measured as a function of hydrogen and methane activity in air at different temperatures between 600 K and 1200 K.

Semiconductor ozone sensors, not expensive in technology and maintenance, are required due to both the increasing industrial ozone applications and in view of the need of O₃ monitoring in some work places. In this work the design and technology of a thin film semiconductor ozone sensor are described. The sensing layers are In₂O₃ thin films doped with iron or cerium. The sensitivity as a function of working temperature and film thickness at a given ozone concentration is described. The dynamic response and recovery times of the sensor under the influence of ozone atmosphere are also discussed.

In this work the application of a-Si:H thin film transistor technology in the field of chemical sensors is presented. In particularly, the optimization of magnetron deposition process for obtaining various silicon nitride films and TFT structures are described as well as adequate structures of Ion Sensitive Field Effect Transistor with respect to the ion sensitive hydrogen properties are studied. The device shows a good Nernst response and high reproducibility but not acceptable stability yet.

This paper describes the development of NH₄⁺- sensitive membranes based on various polymer materials incorporating nonactine as the ionophore for long-term performance CHEMFETs. Different composition of membranes based on plasticized PVC, carboxylated PVC, plasticized PVC modified by decylmethacrylate, polysiloxane and Siloprene were studied. Although polysiloxane membrane presented the most improved adhesion to the chip surface, the Siloprene membrane was successfully applied to design durable NH₄⁺-sensitive CHEMFETs. These sensors showed NH₄⁺-responses with good selectivity even after 14 months of continuous exposure to conditioning electrolyte.

In this paper the first nitrite-selective and perchlorate- selective CHEMFETs based on plasticized PVC membrane containing anion-sensitive receptors were presented. The designed sensors exhibit good selectivities for primary ions over other inorganic anions and show linear responses in the range 1 - 3.5 of pX^- with a slope of 32 - 42 mV decade^-1. These microdevices can be applied in the determination and the monitoring of nitrite and perchlorate anions (even in the presence of some interfering ions).

The purpose of the work was to design a high frequency ultrasonic probe with PVDF foil. The constructed probe was analyzed by modified Mason's computer model and validated experimentally. The coaxial cable, the compensating circuit, the transmitter and receiver impedances as well as the acoustical loading of the back transducer surface were taken into account. The result of study show that the overall sensitivity increases when the inductance in series compensating the clamped capacitance C_o is applied and that the frequency of the transfer function maximum becomes twice lower than the transducer resonance frequency if the back transducer surface is loaded with a material of a high acoustic impedance.

Effects of different ways of sample feed to the sensor, types of used membranes, extent of stretching the membrane pack by working electrode and timing of excitation voltage on performance of amperometric glucose biosensor with oxygen indicating electrode were investigated. In the sensors, enzymatic membranes containing immobilized glucose oxidase and some auxiliary membranes constituted an easily detachable laminated pack. In one of the tested sensors position of the membrane pack with respect to working electrode was adjustable. It was found that the above factors, except the timing of excitation voltage, have not essential influence on performance of O₂-type glucose biosensor.

In this paper, a simple chemical method of urease immobilization on silicon nitride surface is described. As a basic structure to construct urea-biosensor, a pH-sensitive Si₃N₄-gate ISFET was used. The developed method of chemical immobilization of urease is based on Schiff's base formation. The developed EnFET type urea biosensor are characterized by the following parameters: (1) maximum analytical signal: 120 divided by 140 mV in 10 mM phosphate buffer solution, (2) linear range of the (Delta) U_gs equals f(logC_urea): pC_urea(2 divided by 3.5) in 10 mM phosphate buffer, (3) response time: 80 s and (4) lifetime: 35 days with the stable analytical signal then after 52 days this signal decreased by at least 40%. The influence of the concentration as well as the pH of the buffer solution on EnFET response were investigated.

The new method and the device dedicated especially to viscosity measurements of physiological fluids is presented. In the electrofluidic programmable oscillator generating the alternating flow in the hydraulic capillary resistor (the actual sensing element), the electric current proportional to the pressure drop on the hydraulic resistor is measured twice during each period when the driving coil of the electromagnetic actuator passes the same point but in opposite directions. The measured current is then processed in the way making the final result of measurement absolutely independent of zero drifts of mechanical and electrical parts of the measuring system. Also non linearity connected with the `end effects' of the capillary resistor is eliminated by the processing procedure. The viscometer needs a very small dose of a measured fluid (less than 0.15 cm³). Results of tests are also included showing a good linearity and accuracy of the viscometer.

The aim of this paper is to present the results concerning the influence of visual echo and reverberation on the speech process of stutterers. Visual stimuli along with the influence of acoustic and visual-acoustic stimuli have been compared. Following this the methods of implementing visual feedback with the aid of electroluminescent diodes directed by speech signals have been presented. The concept of a computerized visual echo based on the acoustic recognition of Polish syllabic vowels has been also presented. All the research nd trials carried out at our center, aside from cognitive aims, generally aim at the development of new speech correctors to be utilized in stuttering therapy.

The work presents the construction of a device, which transforms speech sounds into acoustical and tactile signals of echo and reverberation. Research has been done on the influence of the echo and reverberation, which are transmitted as acoustic and tactile stimuli, on speech fluency. Introducing the echo or reverberation into the auditory feedback circuit results in a reduction of stuttering. A bit less, but still significant corrective effects are observed while using the tactile channel for transmitting the signals. The use of joined auditory and tactile channels increases the effects of their corrective influence on the stutterers' speech. The results of the experiment justify the use of the tactile channel in the stutterers' therapy.