The paper describes a FPGA based peak detector. The present design is aimed for signal processing coming from a magnetoresistive current sensor, but it can be used for any kind of signal. The maximum value of the signal is determined using the derivative sign change from positive to negative means positive peak and sign change from negative to positive means negative peak while the signal is positive or respectively negative. Two thresholds are used in order to separate the absolute peak from other relative peaks in the waveform. The peak detection is performed comparing the signal with a...
This paper presents innovative schemes of “full-flash” and “subranging” A/D converter architectures. These new architectures are based on a conversion technique inferred by an electrical interpretation of the calliper rule. This kind of ADC implementation allow the dramatic reduction of the required resistors. Indeed, while a traditional full-flash or subranging ADC requires a voltage comparison scale realized by a series of 2n resistors, being n the number of bits of the resulting binary samples, the proposed architectures require only 3*2n/2 resistors. This reduction produces an obvious...
In the paper, influence of quality of measurement data on quality of data warehouse, which is required in the process of knowledge acquisition, has been shown. Factors crucial to quality of data in the data warehouse, criteria of quality of data warehouse and indices of quality of measurement data have been presented. These elements indicate requirements for measurement systems and processes of transforming data from sources into data warehouses.
From many years in various science and technical areas there are introduced data fusion methods, lately also in metrological applications. Now there are conducted investigations connected with determining of importance of data fusion in classical metrology, complex measurement systems and also in measuring-control, diagnostic, classification systems, etc. The paper presents author’s point of view on data fusion process. It pointed that using of data fusion methods in metrology is possible and purposeful. Data fusion process in the paper is presented on example of the phase angle measurement...
In the paper, a comparative method of measurement of the capacitors by measuring the voltages across them and phase angle between is presented. In the analysis of errors the systematic loading effects of the connection and their elimination has been described. The reductions of the systematic and the random errors of sampling and quantization have been performed in the frequency domain. Application of the method is possible with support of the modern digital signal processors and with interpolated DFT to improve the accuracy and speed of the measurement.
The comparative analysis of lossy transformation compression algorithms for measurement signals is presented in the paper. A limiting error criterion and testing signals of synthetic character were proposed for comparing the compression algorithms. The application of such algorithms to test the lossy compression algorithms makes the results obtained in such a way independent of the shape of a single signal and makes them valid for the whole class of measurement signals while the determined limiting errors assume the character of maximum errors. By varying the parameters of the synthetic...
Analysis of acoustic signals is a popular method of wireless detection of glass breaks in alarm systems. In most cases detection of some frequencies is applied for this purpose. Unfortunately, methods like this are not enough resistant to other (false) signals. Better results can be achieved using of JTFA for signal decomposition. To develop a robust method of glass breaks detection the authors applied Wavelet Transformation (WT). First results presented in [1] and [2] did not meet strong requirements of VdS standard. In this paper a new approach based on Rock Solid Attributes (used in...
A bridge, suitable for 1:1 and 10:1 ratio measurements of four terminal-pair impedances to frequencies up to 5 MHz, has been constructed and is presently under testing. The purpose of the bridge is to extend the Italian national standard of capacitance toward higher frequencies; however, the bridge will be employed for resistance comparisons also. Expected best uncertainty is in the order of a few parts in 10-5 for 10 nF - 1 nF ratio measurements, at 1 MHz.
In this paper we present the procedure to calibrate the Optical Time Domain Reflectometer, one of the most used instruments in the measurement of optical fibers. At the same time, since the procedure of calibration imposes the study and the development of a sample/artefact called recirculating delay line, we have studied and described its realization and calibration.
In this paper we present a technique to improve the accuracy of a measurement system. This technique is based on the arithmetic of the integer numbers in finite fields and represent an extension of the well known “calliper rule”. The said technique is explained by using some simple measurement examples, in particular length, time and mass measurements. Some related possibilities of improvement for the modern instrumentation are suggested and discussed.