The quality of a measuring system depends more and more on the first stages of the measuring chain i.e. the sensor and the primary signal conditioning circuit. The use of a high resolution A/D converter at the very beginning of that chain is generally correct. In practice however, sensors are mainly analogue and they need some analogue signal conditioning circuits. The paper deals with the analogue signal processing in the circuits with a single passive sensor. Uncertainty, error elimination and a nonlinearity of some essential structures have been analysed. The general conclusions may be...
The paper presents one of errors of particular sampling method. The method basis on taking samples at particular time moments which enables us to calculate the value of chosen harmonic component in vector form. Additive and multiplicative noises have been analysed and averaging influence on the final result as well.
Practical usefulness of the result of spectrometric data correction depends considerably on how precise its uncertainty is assessed. If the algorithm used for correction is linear with respect to the data and all intermediate results of computation, and if it does not use the data or intermediate results of computation more than once, then the linear propagation of uncertainties represented by intervals, executed step by step for each operation, yields a satisfactory estimate of the measurement uncertainty. Otherwise, a tendency to overestimate the uncertainty appears. An effective...
Quality statements for calibrated measuring instruments give the systematic error and the uncertainty of measurement at the moment of calibration. In contrast to this, the statement of conformity for verified measuring instruments indicates whether or not the error limits on verification specified by law are exceeded. The conformity assessment is based on the result of a previous calibration. The calibration uncertainty thus becomes an uncertainty of conformity decision. There is, therefore, a certain risk for the manufacturer that acceptable instruments might be rejected. The probability of...
The main problems related with taking into account the a priori knowledge about the measured signal have been outlined. Then two examples have been presented, showing how the knowledge about one signal parameter narrows down the uncertainty about the other one. Firstly, bounding curves for the meansquare value when the mean value is known have been examined and some practical conclusions concerning single and multiple signal rectification have been presented. Then the mean value uncertainty for a given signal bandwidth has been studied.
The paper addresses development of metrology software for the evaluation and expression of measurement uncertainty. It is based on representing measurement results as a probability density over allowable values of the measurand. The architecture of a general code aiming at the treatment of any kind of measurement transformation is discussed and a first core module is presented, concerning linear time invariant processes. The output of the program is a probability density, which is calculated on the basis of available information, without using simulation. Standard and expanded uncertainty...
The contribution deals with evaluation of uncertainties in the process of calibration of multicomponent sensors with special aim to force matrix sensor arrays. Matrix sensors are designed for simultaneous measurement of acting forces. It is used in applications in which sensing of varying forces acting in an area is needed (e.g. in robotics, telemanipulating devices, medical applications). Model for calibration of matrix sensor arrays and the methodology for uncertainties and covariances calculation is submitted. The base is regress polynomial model of calibration. The result is estimation...
Calibration of the ultrasonic distance sensor is described in the paper. Measuring range of the sensor is 100 - 600 mm. Design scheme of the calibrating device is presented. The calibrating device utilises gauge blocks as a standard. Nonlinear mathematical model of the calibration is presented. Matrix method for the unknown parameters estimation is described. Analysis of the type A and type B sources of the uncertainties is given as well as their evaluation.
In the article there has been presented the methodology of working out results of mutually coupled measurements of shape deviations and axis location of large engine elements carried out by non-referential methods. There has also been presented a way of estimating measurement errors of shape deviations and axis location deviations of cylindrical outer and inner area complexes.
Processing of multimedia applications in digital computing environments requires support of qualities, such as low jitter between video frames, known from current television or radio. This is especially difficult in these environments due to various noises coming from the hardware and software. In this paper we present (1) a novel scheduling software system for multimedia applications, (2) the measurement of quality parameters (e.g., skews, jitters) that are important for multimedia applications; and (3) evaluation of these measurements using uncertainties. Our Dynamic Soft Real Time...