Papers by Keyword: Measurement Method

Abstract: The article presents a study of a turbine blade profile and roughness measurement processes - the task facing any manufacturer of this part. The blade is one of the most complex regarding parts manufacture because of its complex profile. This profile should be measured in several sections on the feather on all profile elements - the suction side, pressure surface, leading and trailing edge of a blade. If the blade has a shroud platform, its profile should be also measured (and possibly the gland packing profile). It is also necessary to measure the feather end and base of blade profile. Finally, a separate independent task is the blade tang profile measurement.

Abstract: This paper introduces some representative measurement methods of friction coefficient for plastic deformation of metals under high strain rate both in our country and abroad in recent years, and mainly includes several measurement methods of friction coefficient based on the upsetting, forging, extrusion and tube hydroforming. Furthermore, the working principles, applicable occasions and technical characteristics of these methods are explained, and the development of these methods in the future are presented.

Abstract: The method for Lu determination in Yb preparations enriched in 176Yb by atomic and emission spectrometry with inductively coupled plasma (AES-ICP) is reported. The relative determination error from 0.0001 to 0.1% of Lu mass is less than 40%.

Abstract: This paper presents a power consumption model with harmonics existing in power system, the influence of harmonic linear load and the influence of nonlinear load energy metering is discussed, then the analysis of the impact of the harmonic of induction watt-hour meter and electronic watt-hour meter measurement features is given. In the next part, the measurement principle of harmonic watt-hour meter is introduced, and a new type of electric energy metering scheme based on harmonic watt-hour meter is given, so that the electric energy metering fairness problem caused by power grid harmonic will be solved effectively.

Abstract: The armature trigger position of multi-stage electromagnetic coil gun has great influence on the exit velocity of projectile. The energy conversion efficiency of the coil gun can be improved effectively if the armature is triggered in the optimum position. So it is important to detect the projectile position in time. Several typical electrical and optical methods for position detection are summarized in this paper. The advantages and disadvantages of each method are analyzed and evaluated. And a new laser scattering measurement method is proposed. Results show that optical detection method is simple and easy to implement, but it is susceptible to environmental impacts.

Abstract: In this paper, the infrared signal is collected through the Cassegrain optical system, and then before exhaust thermistor detector is collected infrared signal into a voltage signal in the converted voltage signal corresponding processing, such as signal amplification, filtering and demodulation processing, the processed signal and system parameters in real-time control of the comparisons of the relative distance of the vehicle in front, followed by the MCU through the vehicle in front distance value judgments and to follow up the speed of vehicles, in order to achieve the use of infrared technology to detect the distance of the vehicle in front, and unmanned exploration technology focal car fleet .

Abstract: Dynamics of projectile penetration into sand depends greatly on the features of motion and state of the sand material at the interface with the projectile. The goal of this study is to clarify the behavior of projectile during penetration under the impulse loading induced by the plate impact using a vertical powder gun. In this paper, we constructed an accurate and reliable technique for measuring projectile penetration velocity into sand. “Magnet-Coil” gage method was suggested on the basis of electromagnetic induction phenomena due to movement of the projectile having magnet. We confirmed that it has sufficient measurement accuracy.

Abstract: The phase characteristics of the high frequency pulse tube cryocooler which include the mass flows, the pressure amplitudes, and the phase angles between them significantly affect the cooler performance. A measurement method by using pressure sensors, temperature sensors and linear variable differential transformer rods is presented to evaluate and estimate the phase characteristics for the key components within the cooler such as the compressor, the regenerator, the inertance tube. etc, also the construction method of the phasor diagram based on the measurement is given. The constructed phasor diagram can be used to compare with the design values and provide the optimization direction of the prototype.

Abstract: The heterodyne laser interferometer is widely applied in ultra-precision displacement measurement, but its accuracy is seriously restricted by the optical nonlinearity which arises from the optical mixing in the reference and measurement arms. In an ideal heterodyne laser interferometer, the beam from the laser source consists of two orthogonally linear-polarized components with slightly different optical frequencies and the two components can be completely separated by the polarizing optics, one traverses in the reference arm, the other traverses in the measurement arm, both of them are in the form of a pure optical frequency. However, in a real heterodyne laser interferometer, due to the imperfect laser polarization, the optics defect and the misalignment, the two components of the laser beam cant be perfectly separated, therefore both of the reference arm and the measurement arm contain a portion of the two laser components, which leads to an optical mixing in the two arms of the heterodyne interferometer and causes the cyclic nonlinearity of several to tens of nanometers.

Abstract: This paper presents an experimental investigation into the axial strain measurement method of fiber reinforced polymer (FRP)-confined normal-and high-strength concrete (NSC and HSC). A total of 15 FRP-confined concrete specimens with circular cross-sections were tested under monotonic axial compression. Axial strain recordings were compared on specimens instrumented with three different measurement methods: axial strain gauges and full-and mid-height linear variable displacement transformers (LVDTs). The ultimate conditions are tabulated for each measurement method and key experimental outcomes discussed. The results indicate that axial strains of FRP-confined HSC are highly sensitive to the instrumentation arrangement and significant differences occur in the results obtained from different measurement methods.