A precise power amplifier is described in the paper. It was designed to amplify the output ac voltage of a digitally synthesized source from 5 V to 5, 10, 20, 30 or 50 V in 0… 1 kHz frequency range. The five voltage gain coefficients may be selected by GPIB and RS-232 interfaces or from the keyboard. The main application of the amplifier is the ac-dc voltage calibration system, especially useful for evaluation of thermal converters at low frequencies.
The paper presents assumption for a microprocessor measurement-control system (MMCS). For synthesis this system the Petri net was used. On the basis of the analysis of the operation of MMCS there were formed sets of elementary events and conditions defining when particular events could take place, or conditions resulting from a given event. On this basis a Petri net for MMCS was worked out. Using formally prepared specification of the task, a general idea of software was worked out. For application idea of software is used of the SFC language for PLC controllers.
Networked measurement-control systems are widely used in applications ranging from difficult process control to simple discrete manufacturing. Usually, this systems impose real-time requirements to the nodes and communication networks. In the paper current trends in measurement-control system architecture and use of scheduling theory to verify on designing stage deadline constrains are presented. At the end use of offline scheduling method to worst-case response time in one level system based on CAN network is shown.
This paper presents a processing formula of an inductive transducer for conductivity measurements of conducting materials. On the basis of this formula, an analysis of metrological properties for a flow version of the transducer has been performed. This type of the transducer consists of a coil wound round an insulating pipe of which – coaxially with the coil – a cylindrical sample of investigated material is placed. The aforementioned processing formula of the transducer has the form of a dependence between – on the one hand – the changes of impedance observed at terminals of the coil and –...
In this paper we use four texture features of ultrasonic images for the classification of heart disease. The texture features are measured from a gray-level cooccurrence matrix generated from the heart images and are used as inputs to our classification system incorporated with soft computing technologies, which include fuzzy logic-based systems, neural-network-based systems and genetic algorithms. We evaluate the performance of our proposed method in terms of sensitivity, specificity and overall accuracy. Experimental results show that the proposed method has potential utility for...
The paper presents a method of determining the quality of adhesion based on the analysis of the supersonic wave driven by the Dirac potential impulse. Analysis of the response signal by means of linear prediction coding assumes similarity between generating speech in the vocal tract of the larynx and generating the response of the steel anchor to Dirac impulse function. The model of the vocal tract used in the analysis of voiced sounds by LPC was used for the analysis of the response signal of the steel anchor driven by a train of impulses. The purpose of this research is the analysis of...
In this article the metrology verification technique of electrical conductivity tomography system is proposed and investigated. The verification is based on the reference model of conductivity distribution that is constructed as a network of the discrete resistors (conductors). Proposed technique permits to verified the data acquisition system, reconstruction algorithm and approximation effects jointly or separately. The reference network parameters and the stages of the verification algorithm are in details described.
Many have observed that measurement, knowledge generation and advancement are companion activities. The evidence for this assertion comes from sources over the long history of mankind. Better understanding of these connections appears to be able to yield advances in knowledge generation systems. Current understanding of the meaningful nature of measurements lags way behind other aspects and is a major area needing attention by use of multiple styles of thinking found in both the hard and soft sciences. Internet messaging has opened up new horizons in collection, storage and dissemination of...
Eddy current inspection is a fast and effective method for detecting and sizing most of the flaws in conducting materials. The inverse problem solution i.e. inferencing about possible defect, based on the measurement signal from the eddy current probe, is a difficult task In this paper an implementation of artificial neural networks for multi-frequency eddy current testing on conducting layers (aluminum, copper) and ferrous tubes has been presented.
A simple and effective method of parameter identification for a linear model of aperiodic processes with known time delay is presented in this paper. The process time lag order and, subsequently, the remaining model parameters are determined from a few samples of the initial phase of the process step response.