A simple method for measuring the dielectric constant of solids

This paper presents a simple method for determining the dielectric constant of a solid material. The method consists of measuring the return loss due to a slab of such material inserted into a rectangular waveguide. The dielectric slab presents a discontinuity inside the waveguide, and the electric field at each interface of the slab is described as a summation of weighted sinusoidal basis functions. The scattered magnetic field on either side of the slab is determined using the modal expansion approach. These weights are solved by using the method of moments on the boundary conditions of continuity of the tangential magnetic field at the interfaces. The component of the electric field (scattered) for the dominant TE₁₀ mode can then be determined in terms of these weights, and from this result the reflection coefficient can be theoretically evaluated. A comparison between the experimentally obtained reflection/transmission coefficient and the theoretical values provide a figure for the dielectric constant of the material     

Accurate analysis of smoothly modulated AC waveforms applied to the calibration of fluctuating harmonic analyzers

Calibrated harmonic analyzers are required to underpin international regulations regarding harmonic emissions for electrical appliances. A method to accurately analyze waveforms containing smoothly fluctuating harmonics is described. The response of an analyzer to the characterized waveform is considered and a method to calibrate an analyzer is presented.     

A method for determining errors in measuring systems

Translated from Izmeritel'naya Tekhnika, No. 11, pp. 27–28, November, 1992.     

A novel microwave method for measuring the complex dielectric constant of polymer thin sheets

A new method of measuring the complex dielectric constant of a thin sheet of polymer samples at microwave frequency is presented. In order to obtain the complex dielectric constant in terms of reflection coefficient, a higher order power series solution has been introduced. Application of lower order power series solution to the greater thickness of the sample requires a frequency of less than 1.5 GHz. To overcome this constraint and to extend the range of working frequency, the higher order power series solution is used to obtain the complex dielectric constant. This method is used to measure the complex dielectric constant of poly(ethylene vinyl acetate), polyurethane, polyvinyl acetate, and polystyrene. The results obtained are in good agreement with literature. Electronic Publication     

An acoustic method of measuring the universal gas constant and Boltzmann's constant

Precision measurement is considered for the universal gas constant and Boltzmann's constant. An acoustic method can be used with a spherical cavity to raise the accuracy in measuring these fundamental constants by measuring the volume of the almost spherical cavity by microwave methods.Translated from Izmeritel'naya Tekhnika, No. 1, pp. 5–7, January, 1994.     

Operational method of measuring the parameters of a harmonic signal

A method of measuring the parameters of a harmonic signal containing a constant an slowly varying component is proposed and investigated. The method has optimum interference proctection. Expressions are obtained for the algorithms for processing the input signal in analog and digital versions, an estimate of the errors in measuring the parameters is given, and the principle for constructing a digital microprocessor measuring instrument is described. Translated from Izmeritel'naya Tekhnika, No. 7, pp. 47–51, July, 1995.     

A method and instrument for measuring the capacitance switching time of nonlinear capacitors

A device and procedure for measuring the switching time of the capacitance of nonlinear microwave capacitors, based on ferroelectric films and bulk ceramics (variconds) when acted upon by controlling electric field pulses, are considered. The method can be used to measure high-speed semiconductor varactors, microelectromechanical components and the residual polarization of capacitors based on a linear ceramic.     

An optimally noiseproof method of measuring the frequency of harmonic signals

Translated from Izmeritel'naya Tekhnika, No. 4, pp. 50–52, April, 1992.     

A method of determining the instrumental component of the error of high-precision equipment for measuring complex reflection coefficient

A method of constructing an adequate model of the instrumental component of the uneliminated systematic error of high-precision equipment for measuring complex reflection coefficient is considered, which enables the contradiction between the effort involved in realizing the model employed and the error in estimating the metrological characteristics of the equipment to be resolved. __________ Translated from Izmeritel’naya Tekhnika, No. 10, pp. 64–67, October, 2006.     

A measuring and computing method and device for determining arterial blood pressure parameters N humans

A measuring and computing method and device are proposed for determining the essential arterial blood pressure parameters in humans by a noninvasive method, not requiring an occlusion cuff. Consideration is given to the working principle of the primary transducer, as the chief unit in the device, and to a computing algorithm for calculating the essential arterial pressure parameters as a systole and diastole in a digital artery.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 60–62, April, 1994.     

A direct method of thermal time constant measurement for lithium tantalate based terahertz pryroelectric detectors

Thermal time constant (τ _th ) is one of the most important parameters of pyroelectric detectors (PEDs). However, unlike other parameters such as voltage responsivity (R _v ), noise equivalent power and specific detectivity (D*), measurement of τ _th of lithium tantalate (LT) based PEDs was seldom reported in literatures. In this work, a convenient direct method for the measurement of τ _th was presented according to theoretical analysis and simulation result. Afterwards, this method was successfully applied to practical measurement of a homemade current mode terahertz (THz) LT based PED, of which τ _th was measured to be about 882 ms. To verify the measured result, τ _th was also calculated from the measured voltage-time curves according to its theoretical expression, which agrees well with the measured one. Compared with indirect measurement of τ _th through frequency response curves of PEDs, the direct method is simpler and more accurate. Furthermore, this method suggested an easy way for the measurement of pyroelectric coefficient of PEDs.     

声时差法测定螺栓的预紧应力

本文利用超声波沿轴向传播时的波速同轴向应力以及三阶弹性常数的关系，推导了声时差与应力的关系，采的时差法多探头同时测量同一法兰上的各螺栓的预紧应力，整个过程中各探头位置不变，可以克服多次耦合误差并使测量过程简便，精度高，本文还应研究了温度变化对声时差的影响，提出并且从实验数据算出几个只与材料有关，与螺栓的夹紧距离，直径以及总长我关的常数，使测量和应力计算变得简单，实验结果表明应力低于２４０ＭＰａ，夹     

A method for measuring the speed of light

Measurement Techniques -