Pressure Transducer Based on Tensosensitive Films of Bismuth–Antimony Telluride

A new design of a semiconductor pressure transducer based on tensosensitive films of bismuth–antimony telluride, which provides a temperature compensation for the entire device structure, is proposed. The technical data of the tensometric transducer proposed for measuring the pressure of liquids and gases are presented.     

Features of the measurement of current strength by a thermoelectric transducer

The problem of measuring a pulsed current using a thermoelectric transducer is considered. It is not possible to measure all currents by direct reading from a thermoelectric transducer. The measurement of some currents requires the use of appropriate coefficients. Translated from Izmeritel'naya Tekhnika, No. 2, pp. 38–39, February, 1999.     

Thermoanemometric transducer of pressure derivative

Conclusions The lower limit of the range of the transducer of p is given by the permissible reduction in the device sensitivity due to convection at low flow velocities while the upper limit is given by a reduction in the thermoanemometer sensitivity caused by an increased flow velocity. The static characteristic of the instrument is to a considerable extent nonlinear because of the nonlinearity of the thermoanemometer.The transducer time constant is the resultant of two components: of the time constant of the chamber and channel (pneumatic component) and the time constant of the thermoanemometer (thermal component). In the case of correctly selected chamber and channel components the time constant of the thermoaneommeter may be assumed to remain constant over the entire measurement range, being dependent only on the dynamic properties of the selected thermistor and on the coefficient of negative feedback in the system T=const. The time constant of the penumatic part of the instrument is determined by the upper and lower limits of the thermoanemometric device measuring p at the given sensitivity threshold of the thermoanemometer.The temperature and density errors of the transducer are large and necessitate the use of special compensating devices if the instrument is to be used over a wide temperature and pressure range.Translated from Izmeritel'naya Tekhnika, No. 1, pp. 45–48, January, 1973.     

Determination of temperature corrections for the dimensions of machine details

Conclusions The above semiconductor thermometer with a special transducer is convenient for measuring the temperature of flat, spherical, and fashioned outer and inner surfaces.The special transducer provides temperature measurements lasting not more than 10 sec. The error in measuring temperature does not exceed ±0.3°.The above technique for determining corrections of temperature deviations from the normal of the article and the measuring instrument by means of a semiconductor thermometer and special graphs raises the accuracy of measurement and productivity in manufacturing precision articles on metal-working machines, and reduces the percentage of rejects due to inaccurate measurements.The above technique and instrument can be used under workshop conditions at the bench, in the Technical Control Division (OTK), inspection and test points, in factory test laboratories, and in GKLs for measuring equipment of the State Committee of Standards, Measures, and Measuring Instruments of the USSR.     

Verification of the duplex gauge using variable strains and temperatures

Four steel specimens were equipped with "duplex nances", a recently proposed transducer based on two different electrical resistance strain gauges, capable of correcting the effects induced by temperature. The examined innovative transducer, in comparison with traditional strain measuring systems, has the advantage of utilising two strain gauge channels of the same type, which significantly simplifies automatic measuring systems. The specimens were subjected to temperature and strain field variations in the ranges of=30–150°Cand=100–700μm/m respectively The temperature and strain values obtained from the duplex gauges were compared with those measured by means of traditional methodology, i.e. a strain gauge and a thermocouple.     

非线性传感器静态特性评估的极限点法

基于对测量过程、测量误差的认识，提出了一种利用极限点法评估非线性传感器静态特性的一种新方法。给出了利用该方法评估非线性传感器的两种模型。并以一电涡流式非线性位移传感器的标定数据进行了计算、分析。     

超声波换能器性能指标测试方法的研究

介绍了一种新的超声波换能器灵敏度的测试方法，排除了常规测试方法中仪器对它的影响。对超声波换能器的频率特性测试，采用了一种简便，经济，实用的方法，并给出了测试结果。     

谐振弦式传感器理论公式修正方法及应用

在简要导出谐振弦式传感器理论公式的基础上，阐述了修正理由，给出了修正公式，实例计算表明，修正公式能显著提高计算精度，最后，利用修正公式对所研制的５０ＭＰａ谐振弦式压力传感器的标定数据进行了处理，给出了相对计算误差。     

A novel experimental technique to determine the heat transfer coefficient between the bed and particles in a downer

A novel method for directly measuring the temperature history of mobile hot ferromagnetic particles (steel particles), substituting for reacting particles, in a binary-solid (reacting particles and inert particles) downflow is introduced. The temperature history of the hot steel particles can be obtained by measuring the temperature of the particles at different axial positions using magnetic fields that can separate the steel particles from other bed materials immediately and easily. Employing the magnetic marking method, magnetic sensors were used to detect the change in magnetic flux density in a given magnetic field, and the residence time of the steel particles was also measured. The cross-sectional averaged particle-to-bed heat transfer coefficients were calculated from the experimental results using simple heat balance equations. The measured temperature data have a relatively wide error range; however, the average temperature curves derived from the average particle-to-bed heat transfer coefficients agreed with the temperature plots. Therefore, the experimental method of this study is applicable to the measurement of the particle temperature in a binary-solid downflow. The results showed that there is strong correlation between the particle-to-bed heat transfer coefficients and normalized collision frequency under the laminar gas flow conditions.     

Investigation of the Metrological Characteristics of Calorimetric Transducers of Laser Radiation Energy

The results are given of experimental investigations of calorimetric cavity transducers for measuring the energy of short-pulse laser radiation used in secondary and working standards and also in high accuracy measuring instruments. The sources of the basic error components of the transducer are analyzed and their values are estimated. An averaged value of the basic error of the transducer is obtained.     

In vivo scattering measurement of biological tissue by the use of a pyroelectric polymer transducer

We propose a new method, to our knowledge, for noninvasive scattering measurements of tissues by the use of a pyroelectric polymer transducer, poly(vinylidene fluoride trifluoroethylene) film. In this method, samples are irradiated with nanosecond, low-energy light pulses delivered from an optical fiber, and the pyroelectric signal induced by the diffuse reflectance is measured with a transducer. The signal is then converted into diffuse reflectance by use of a calibration factor. The validity of this method was confirmed by our measuring the scattering coefficient of a white acrylic resin within an accuracy of +/- 15%. We attempted to apply this method to the estimation of scattering coefficients of normal and burned skins in rats in vivo.     

Properties of indium antimonide thin films as fast-response pressure transducers

Results are presented of studies on the application of InSb thin films for measuring rapidly varying pressures up to 600 atm in liquid non-conducting media. A comparison is made between this transducer and the quartz pressure transducer used as devices for measuring rapidly varying pressures. The dynamic error in a pressure-measuring system which included an indium antimonide thin film resistance transducer has been determined as less than 1.5%.     

Mathematical Model of the Error of a Magnetostrictive Displacement Transducer

A generalized structural diagram is given for an intelligent magnetostrictive displacement transducer (MDT) that converts displacement into code. A logometric mathematical model is constructed for the random error distribution in the MDT, with a normal distribution for the independent random errors of the measuring and reference channels.     

A new point contact surface acoustic wave transducer for measurement of acoustoelastic effect of polymethylmethacrylate

A new acoustic transducer and measurement method have been developed for precise measurement of surface wave velocity. This measurement method is used to investigate the acoustoelastic effects for waves propagating on the surface of a polymethylmethacrylate (PMMA) sample. The transducer uses two miniature conical PZT elements for acoustic wave transmitter and receiver on the sample surface; hence, it can be viewed as a point- source/point-receiver transducer. Acoustic waves are excited and detected with the PZT elements, and the wave velocity can be accurately determined with a cross-correlation waveform comparison method. The transducer and its measurement method are particularly sensitive and accurate in determining small changes in wave velocity; therefore, they are applied to the measurement of acoustoelastic effects in PMMA materials. Both the surface skimming longitudinal wave and Rayleigh surface wave can be simultaneously excited and measured. With a uniaxial-loaded PMMA sample, both acoustoelastic effects for surface skimming longitudinal wave and Rayleigh waves of PMMA are measured. The acoustoelastic coefficients for both types of surface wave motions are simultaneously determined. The transducer and its measurement method provide a practical way for measuring surface stresses nondestructively.     

B1 瓦特计测量声功率方法的分析和简化

本文给出郎之万Ｌａｎｇｅｖｉｎ型换能器及变幅杆振动节点、腹点处振幅比随负载的变化情况，分析了瓦特计法测量声功率本身存在的理论偏差，并给出了两性能相同的换能器对接系统的实验结果，表明这种方法在轻负载（不大于水负载）测量中的准确性，提出工程上简化的测量方法     

Use of a ultrasonic transducer array for measuring the velocity and attenuation of leaky acoustic waves

We suggest a new method for measuring local values of the velocity and attenuation of leaky acoustic waves, which is based on wave field measurements using an immobile array of receiving ultrasonic transducers. In comparison to the methods using a single focused transducer mechanically scanned over a given region of the sample, the proposed technique is advantageous in having a higher operation speed due to the electronic switching of receiving channels in the array and in requiring no high-precision mechanical scanners. A ray model of the proposed measuring system comprising an array of ultrasonic transducers with an electronic scanning facility is described. Theoretical conclusions have been experimentally confirmed by tests on the samples with known properties.     

光纤激光多普勒横向位移传感器

介绍了一种光纤式激光多普勒横向传感器，被测位移和光束方向垂直。该系统采用双通道比相测量方法，消除了低频噪声并且直接得到相对位移量，可以测量从静态到２０ｋＨｚ的振动。文中给出了理论分析和实验结果。     

Enhancement of Signal-to-Noise Ratio of Turbulence Measurements by Cross Correlation

A novel method for the measurement of very low turbulence intensities in fluids, based on a dual heat-transfer transducer and a cross correlator, is described. The minimum measurable turbulence intensity is shown to vary with the square root of the minimum detectable cross-correlation coefficient ?. The effects of finite additive noise correlation and finite lateral separation between the transducer halves are studied. Details are given of an instrument measuring the normalized cross-correlation coefficient between two time-dependent signals in the frequency range 2 Hz-300 kHz with an accuracy of ±0.05? ±0.01. The described correlator is particularly suitable for measurements of quasi-stationary processes. A variation of 10 percent in the level of either input signal results in a correlation error of less than 0.6 percent.     

Use of contactless vacuum thermal transducers in pressure measurements

Conclusions Investigations showed that the TVB-6 transducer can be used with standard measuring equipment (ÉPP-09, numerical voltmeters, etc.) in measuring absolute pressures of 1.33–1330 Pa. The relative mean square error of the transducer is 5%. Its service life is 100 h. The transducer, which is made commercially, is compact and cheap. However, it requires a highly stable feed current and its characteristic is nonlinear.Translated from Izmeritel'naya Tekhnika, No. 12, pp. 42–43, December, 1971.