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The infrared radiation measurement system in the moisture meter based on the cooled PbS photoconductive detector is designed by the authors and analysed in this paper. It consisted of a preamplifier and a mechanical chopper. The basic noise sources and their influence on this measuring system are studied out. One solution for the maximisation signal to noise ratio based on the theoretical and laboratory practical consideration has also been made. Under the circumstances, the possible accuracy of the mentioned system is founded out by the measurement. The final aim is to develop an optimal optoelectronical measuring system for the infrared moisture meter for practical use but with some specific substances firstly. The overall results can be kept in the numerous variety applications later.

Water has an absorption band of four wavelengths, namely 1.2, 1.45, 1.94, and 2.94 micrometers, in the near-infrared light range. When a sample is irradiated with light of the above wavelengths, this sample will absorb light in accordance with its moisture content. As moisture content of wheat increased, reflectance from the wheat sample decreased, which indicates that water is a strong light absorber than a sandy wheat sample. When light hits a sample, several interactions can occur: specular reflectance, diffuse reflectance, absorption, transmittance, refraction and scattering. In this paper we try to find out influence of several interactions on accurate measurement for moisture wheat.

Purpose The purpose of this paper is to develop a system for estimating the position of the active magnetic bearing (AMB) shaft. A new approach using the static and dynamic inductances and complex analytic signal to simplify the estimation procedure. Finite element (FE) simulations are introduced as a part of the system synthesis. Design/methodology/approach The paper presents an AMB displacement estimation system. The system is created with three inductive sensors. The position is computed from refined static and dynamic inductance obtained from complex analytic signals of flux and current. FE simulation is used to relate refined inductances to the displacement and to verify the model. Findings This paper shows the applicability of complex analytic signal transformation on estimation systems. The use of new refined inductance is presented in contrast to the classical approach of static and dynamic inductances. The paper shows that classical approach of static and dynamic inductance is not usable for the presented estimation system. Practical implications For the practical implementation of the presented system, it is necessary to know the exact dimensions of the AMB stator and the voltage and frequency used to supply the inductance estimation system. Originality/value The paper presents a system for estimating the displacement of AMB. The paper introduces the application of complex analytic signal to the estimation of AMB displacement. The mentioned signal is used to compute the new refined inductances. The comparison to the classical approach of static and dynamic inductances is given in this paper. The paper introduces FE simulations to the estimation system synthesis.

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