Abstract:General methods and problems of assembly datum line for large vehicles positioning and building were analyzed. The principle of laser positioning measurement was briefly introduced. Mathematical model of laser positioning for precision assembly of large vehicles was derived, the concept of safety threshold for assembly measurement was proposed, positioning accuracy was analyzed, and which based on it, the precise assembly datum line for large vehicles has been established, the assembly accuracy and efficiency are obviously improved.

Abstract:In order to solve the problem of inaccurate measurement of vibration response of specimens with very low laser reflective intensity under continuous high temperature environment, a high temperature vibration measurement technique based on laser Doppler principle is proposed. This paper studies the enhancement of laser reflection signal, the post-processing of time-domain response data, and the thermal protection of laser vibrometer, and verifies the scientificity and reliability of this method through experiments.

Abstract:In order to solve the problem of unstable performance of polymer bonding material in high temperature environment when fiber Bragg grating temperature sensor is encapsulated in tube, a non-adhesive encapsulation method is proposed. Quartz sleeve is selected as encapsulation material and heated by high frequency CO2 laser pulse. The transmission fiber and quartz sleeve can be reliably welded and the encapsulated sensor can be used. The temperature characteristics of the device are tested. The experimental results show that the fiber grating temperature sensor encapsulated by quartz sleeve has a good linearity between room temperature to 300 C, and can be used to measure the ambient temperature.

Abstract:In order to meet the calibration requirements of the temperature acquisition instrument, a high stability large air temperature calibration test chamber was developed. The box structure and working principle of the test box are expounded. Based on the theoretical model of heat transfer process in the chamber, numerical simulation was carried out with Fluent software. The distribution and variation of temperature field and air velocity field in the chamber were analyzed. The test proves that the test box has high temperature control precision, small temperature fluctuation and good uniformity of temperature field, and can be popularized and applied.

Abstract:In order to meet the requirements of batch and high-efficiency development of aerospace products, an automatic measurement method based on product mathematical model is proposed. On the basis of mathematical analysis of product mathematical model, a calibrated object is preset on the assembly module and its position information is calibrated. The calibrated object is taken as the measurement object in the assembly process and the instrument is used to self-calibrate. Dynamic sampling and automatic evaluation to achieve rapid measurement and determination of assembly status of components. Experiments show that this method has high automation, wide application and strong adaptability. It can reduce the error rate of field data and significantly improve the measurement efficiency.

Abstract:The photonic Doppler Vibrometer system has the advantages of high precision, high spatial resolution and fast dynamic response, and is applicable to high temperature, high pressure and high speed. Data processing is an important technical part of PDV system, which aims to obtain the velocity information of the measured motion body from the measurement data containing a lot of noise. In this paper, based on the fringe method, moving mean filtering and wavelet transform are respectively adopted to deal with the original signal de-noising, singular points and other problems, so as to obtain the vibration information of the measured object. The reliability and universality of the data processing method are verified by comparing the vibration test with the standard laser vibrometer.

Abstract:Aiming at the problem of Tungsten-Rhenium thermocouple tracing at a temperature of 300 to 1500 ℃, the prior horizontal-type calibration furnace is improved. It adopts a symmetric shielding gas method for calibration and adds a set of temperature-resistant cavity seal kit which can vacuumize and fill in inert gas to prevent thermocouple being oxygenized. The test shows that the device has good consistency in calibrating the same thermocouple under the vacuum and charging state; and this device can make calibration for extension-type tungsten-rhenium thermocouple with outer diameter betweenφ3～φ10 and length over 450mm.

Abstract:The principles and applications of infrared micro-thermography technique for semiconductor temperature testing were reviewed. This technique is based on Planck blackbody radiance law, the infrared radiance was measured and then the temperature was calculated. Under the mid-infrared waveband, the highest spatial resolution had been realized, corresponding with the emissivity correction, infrared micro-thermography technique can measure the truth temperature of micro semiconductor devices. This technique was capable of measuring stable temperature thermography, continuous dynamic temperature thermography with millisecond level or even microsecond level temporal resolution, and temperature under pulsed conditions. Infrared micro-thermography has been used widely on temperature testing for varies kinds of semiconductor devices under varies conditions.

Abstract:The radiant temperature is one of the most parameters to show characteristic of radiant source. The emissivity of thermal radiator must be measured accurately to realize testing the radiant temperature. According to the character of flame radiation temperature during ammunition explosion and Plank's law,multi-spectral thermometry is used in this paper to fit the emissivity of flame spectrum, absolute radiometric calibration is done. An equipment based on multi-spectral thermometry is developed to detect flame temperature during ammunition explosion. The on-site experiment and data analysis are done, the accurate flame temperature is achieved by our equioment.

Abstract:High gas temperature is an important parameter which needs precise measurement during developing and producing tests of military hardwares, and can provide data supports for performance evaluation and state monitoring of military hardwares. Research progresses of high gas temperature measurement and calibration technology at home and abroad are introduced in this paper.Advantages and disadvantages of some technology branches are anylized in order to provide reference for high gas temperature measurement in national defence science and solve problems of high temperature measurement.

Abstract:This paper analyses the keytechnical parameters of the rocket engine, determines the test functions and technical indexes of the test bench. The design increases the dynamic characteristics of the bench to reduce the influence of the bench structure on measurement accuracy, increases the axial stiffness and reduces the lateral stiffnessof the movableframe to raise the natural frequency of the frame, eliminates the vibration effect of engine starting to the frame, realizes the design and development of the rocket engine test bench.

Abstract:Temperature is one of the parameters that characterize the state of an object and has important theoretical significance and value in scientific research and engineering applications. Accurate measurement of temperature has been a problem in harsh environments such as oxidation, high temperature, corrosion, and electromagnetic interference. The sensor material is the basis for the ingress temperature measurement. Sapphire single crystal fiber has the advantages of stable physical and chemical properties, high melting point and strong mechanical properties, and is a preferred material for high temperature testing. This paper introduces several methods for temperature measurement using sapphire single crystal fiber, namely sapphire fiber radiation high temperature test technology, sapphire fiber grating high temperature test technology, sapphire fiber optic high temperature test technology, sapphire ultrasonic high temperature test technology The principle, current status, advantages and disadvantages, and development trends of test technology are compared and compared to lay the foundation for sapphire fiber temperature measurement applications.

Abstract:In order to study the performance of the two-position three-way solenoid valve as a diverter under a small flow rate, and a test was conducted to investigate the diverting time difference of a certain type of solenoid valve. The result shows that the diverting time difference of the solenoid valve is negative, and the difference increases as the flow rate decreases. The solenoid valve has good performance in high flow range. In the low flow range, the correction method by double exponential decay function can effectively reduce the uncertainty introduced by diverter. The Study shows that it is highly feasible to use a solenoid valve as a diverter for the standard facility for small liquid flow.

Abstract:Pipeline or cavity always exist before the pressure transducer when measuring pressure because of limitation of installation space, high temperature or complex media. The pressure measurement systems’ dynamic characteristics are often determined by the pipelines. The theoretical research progress of the pipeline dynamic characteristic is first reviewed, and the research results of factors affecting the dynamic characteristic are presented. Then the main calibration methods of pipeline are introduced, and the characteristics and using conditions of different calibration methods are analyzed. The existing problems and the further study needed in the future are finally discussed.