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Roman Tabisz
THE CAPABILITY EVALUATING OF INDUSTRIAL MEASUREMENT SYSTEMS

A usefulness of the best known and widely recommended methods and procedures of measurement systems capability determination is evaluated. A new method is proposed. This method allows correcting the capability index of measurement systems as the capability index of production process is being improved.

Il-Bum Kwon, Chi-Yeop Kim, Man-Yong Choi
DEMONSTRATION OF TEMPERATURE MEASUREMENT DISTRIBUTED ON A BUILDING USING FIBER OPTIC SENSOR

We have demonstrated a feasibility study of the fiber optic sensor to monitor the distributed temperature on a building construction. A fiber optic BOTDA sensor system, which has a capability of measuring the temperature distribution, attempted over several kilometers of long fiber paths. This simple fiber optic sensor system employs a laser diode and two electro-optic modulators. The optical fiber of the length of 1400 m was installed on the surfaces of the building. The change of the distributed temperature on the building construction was well measured by this fiber optic sensor. The temperature changed normally up to 4°C through one day. Also, The temperature distribution of spring season was compared with that of early winter season.

Jouko Kiviö, Paul H. Andersson
TOOL BREAKAGE MONITORING IN A MULTI-SPINDLE DRILLING OPERATION

This paper describes tool breakage monitoring in a multi-spindle drilling using acoustic emission (AE) signals. Measurements have been carried out in a real industry environment with a tailor-made multispindle gun drilling machine. The drilling machine comprises some 300 spindles in one line and it is used to drill holes in paper machine parts. Measured AE-signals have been analysed both in time and frequency domain and especially high frequency content of AE-signals (over 150 kHz) have been examined. Breakage can be detected distinctly over the frequency content of AE-signals born in a normal undisturbed drilling. The location of sensors play very crucial role because the high frequency content of AEsignals attenuates very rapidly with increasing distance between the sensor and cutting process.

Stefan Folprecht, Günther Pfeifer, Jürgen Landgraf
INTEGRATED WIRES FOR STRAIN MEASUREMENT IN COMPOSITES CONSISTING OF CARBON-THERMOPLASTIC MATERIALS

It is possible to integrate strain measurement elements below the surface in fast rotating composite parts consisting of carbon reinforced Polyetheretherketone (CFPEEK).
Such measurement elements are made of resistance wires insulated by a netting of glass fibres. This way it is possible to monitor large portions of a composite part up to the limit of loading.
In this article measurement results are published which were obtained by means of resistant wires embedded below the surface of the composite material. The wires are made from the resisting material ISAOHM.

Falk Tegtmeier, Manfred Peters
STRAIN GAUGE BASED MICROSENSOR FOR SPATIAL STRESS ANALYSIS IN BUILDING STRUCTURES

Strain gauges are suitable for stress analysis in buildings due to their high signal resolution. A long-term supervision requires an encapsulated adaptation because of the chemical sensibility of strain gauge applications. The sensor lifetime depends on the encapsulation seal protecting the strain gauge. Therefore, different concepts were examined and adapted to the specific requests in climatic simulation facilities. The mechanical adaptation of the sensor is decisive for its measuring uncertainty. Various concepts were investigated and a process of mechanical distortion of two conical bodies developed such that the useful measuring range covers the range of elastic deformation of construction steels.

Mikko Ruuska, Paul H. Andersson
SPINDLE BEARING MONITORING USING ACOUSTIC EMISSION

A premature failure of machine tool spindle bearings is a major problem in production and can result in enormous loss in the production and spindle rehabilitation cost. This paper describes a condition monitoring system applied to the spindle of a NC machining centre. During idle run the acoustic emission and vibrations were measured using sensors installed in prepared places. A large number of tests were carried out with varying sensor location, spindle rotating speed and spindle load. Measurements were performed in real industrial environment nine times with six weeks intervals in order to obtain trends. The spindle run out was determined at every measurement time as well.

Janja Turšic, Boštjan Podkrajšek, Boris Pihlar, Štefica Cerjan–Stefanovic, Milko Novic
PROFICIENCY TESTS AND LABORATORY REFERENCE MATERIALS IN ION CHROMATOGRAPHY

International Schools of Ion Chromatography are well-accepted annual meetings among users of ion chromatography in Slovenia and Croatia. Special attention is also given to some features of metrology e.g. tracebility and uncertainty. Within schools, proficiency tests are organized, with the aim of checking the performance of participating laboratories as well as of testing different analytical approaches suitable for certain types of samples. The procedure for preparation of a laboratory reference solution (Cl- and Br-) using primary techniques with direct traceability to SI units is also shown.

Jiri Haze, Michal Skocdopole, Jan Krejci, Radimir Vrba, Lukas Fujcik, Dagmar Krejcova, Zuzana Grosmanova
ARTIFICIAL SYNAPSIS – THE DETECTOR OF PESTICIDE TOXICITY

Fast detection of organophosphorous pesticide toxicity in field conditions has not been fully solved yet. The new tool for field measurement of organophosporous pesticides toxicity is described. The detection is based on the inhibition of acetylcholinesterase. The enzyme acetylcholinesterase is immobilized on a miniature electrochemical detector, which is made by Thick Film Technology (TFT). The dimensions of TFT electrochemical sensor are 7,35 x 25,4 mm. The detector is placed in a narrow gap in which the analyzed sample and acetylthiocholine flow. This arrangement simulates the removal of acetylcholin from synaptic gap. It creates the simple model of synapsis - the Artificial Synapsis (AS).
The AS detects the integral sample toxicity. It enables organophosporous pesticides traces to be detected in washout from leaves as well as their direct measurement in rivers, ponds, vaste waters and drinking water sources. The preconcentration of the sample is possible. The detection limit varies in wide range depending on the toxicity of pesticide.
Structure and function of AS is described. Limit of detection (LOD) was found for pesticide Syntostigmin 10-10 mol.

Jiri Haze, Michal Skocdopole, Jan Krejci, Radimir Vrba, Lukas Fujcik, Dagmar Krejcova, Milan Kraus
PORTABLE DEVICE FOR PESTICIDE TOXICITY ANALYSIS FOR MEASUREMENT IN FIELD CONDITIONS

The new portable microfluidic device for field measurement is presented. It consists of two loop pumps. The first loop asssures the mixing of solution. The 95% of solution circulates through the first loop. The second loop consists of capillary which creates the hydrodynamic resistance and the chamber with biosensor. The Artificial Synapsis (AS) is integrated in the chamber, which detects the integral organophosphorous pesticide toxicity. The 5% of solution circulates through AS. Both parts are integrated in a compact device with size of 200 x 100 x 100 mm.
The signal from biosensor is evaluated by Bioanalyzer electronic unit. It is destinated for detection of traces of pesticides in washout from leaves for direct measurment in rivers, ponds, vaste waters and drinking water sources. The electronic unit contains the unique software for data aquisition and biosensor signal analysis. The whole device consists of two basic units and several accessories. The article describes structure and function of this device.

Adamek Martin, Prasek Jan, Krejci Jan, Fujcik Lukas
GRAPHITE PASTES IN THICK FILM SENSORS AREA

Miniature electrochemical sensors can be produced by thick film technology (TFT). The optimal properties of thick film electrode materials are main problems of sensors design. The optimisation of graphite pastes properties for TFT chemical sensor is discussed. The commercial TFT graphite pastes, which are used for common application, are cheap and easily producible, but they are not efficient for electrochemical measurement. These pastes have insufficient sensitivity and they have other bad properties. Graphite pastes, which were designed for special chemical analysis, are technically known, but these pastes are not workable by screen-printing. The first step in rheological properties addition to graphite electrochemical pastes is the goal of this work. This will ensure the pastes printability that will enable the reproducible mass production.
The graphite powder with paraffin wax mixture is the basic component of common chemical graphite pastes. There were examined different properties of these pastes in dependence on graphite powder and binding material content in this work. Finally there are described some measurement with commercial and specially prepared TFT graphite electrodes. All measurements were done using a standard electrochemical couple of potassium ferrocyanideferricyanide.

Page 890 of 939 Results 8891 - 8900 of 9382