Abstract:A discussion on the problems of calibration of test systems is presented. First，beginning from the definition of the test system and combining the specialties of the target of test systems，the features of test systems is analyzed. Then，aiming at the ambiguity on the calibration of test systems，such as synthetic calibration and system calibration，some definitions are discussed in detail. The characteristics of three basic calibration modes are identified and analyzed. Finally，to the difficulties on drawing calibration specifications of test systems，one scheme is taken out，which is the combination of different single parameter calibration specifications. And both the steps and process for synthetic calibration or system calibration are presented.

Abstract:Torque is main technical index that reflects the output power and performances of transmission shafting，which can provides effective guarantee for reliable operation，fault diagnosis and security maintenance of power equipment via real time monitoring of output torque.It has important implications for torque measurement of transmission shafting.Based on the two kinds of principles of torque measurement in transfer method,strain ( stress) and torsion angle the working principles characteristics and drawbacks of several torque measuring methods and sensor structures that having been researched widely were analyzed in detail.In the future combining with the own characteristics and development of transmission shafting,the torque measurement of transmission shafting should be further developed in the respects: craft improvement of strain gauge testing noncontact measurement measurement of special size shaft method of data handling and design of measurability.

Abstract:Micro pressure measurement is an important and basic measurement technology in the development,test and production of high precision equipment in modern science and technology field.This paper introduces the wide application of micro pressure measurement in practice, highlighting the necessity of emphasizing micro pressure measurement.Through the introduction and analysis of the present situation and development trend of micro pressure calibration instruments,the development of micro pressure calibration in the future is forecasted.?

Abstract:The calibration characteristics of chamfering total pressure probes were studied by numerical simulation in the supersonic condition,and the key impacts of the calibration characteristics were analyzed.The total pressurecoefficient changes with position,pressure,temperature and Mach number.The numerical simulation results were compared with the experimental results.The results show that selecting the installation location has great influence on the total pressure of the chamfer total pressure probe.The absolute value of the pressure coefficient is smaller when the probe is placed nearer to the upstream of the tunnel.The absolute value of the total pressure coefficient of the chamfering total pressure probe decreases with the increasing of temperature and pressure,and increases with the increasing of a number.

Abstract:This paper designed a high-precision temperature-control circuit system based on TEC.Introduction was made to the selectionmethod of TEC,realizing a hardware circuit based on singleˉchip and using PID software control algorithm to optimize parameters.In experiment?choosing the higher thermal load copper block as the temperature control object to do the test verification.The result shows when the ambient temperature is 23℃,the temperature control range of the copper block is (10~40℃).The temperature control precision can be up to 0.01℃.

Abstract:In order to improve the testing accuracy for the steel bar position,Measurement Systems Analysis (MSA) technique is used to systematically test the discrimination,bias,linearity,repeatability,reproducibility and other indexes for the TCC determinator.After analysis,we found the source of the determinator variation,and figured out that determinator had linear bias and data correction was necessary during the process.The determinator can be used to judge if the thickness of concrete cover is qualified or not and make a rough estimate for the process capability index during the construction process.?

Abstract:A method is proposed for measuring the internal clock stability and the adaptability of the environment temperature of taximeters(hereinafter referred to as meters) by using the highˉprecision UTC provided by the Beidou Positioning System as the reference clock source.The meters with three different crystals are used as the experimental objects, and the highˉprecision UTC time for the internal oscillator time was compared with the Beidou Positioning System.By changing the experiment temperature,the temperature effects on the meters’internal clocks were analyzed,and the meters’internal clock differences at 25℃ were recorded for 110 days.Through the analysis of the experimental data,the group of experimental results obtained can objectively reflect the long-term stability.?

Abstract:Thin-film thermocouples have advantages of small volume,simplicity of operation,high accuracy,etc.? In some special cases for accurate temperature measurement,they show the great advantage.By means of magenetron sputtering method in the production ofthermocouples,the material composition possibilities are almost unlimited.In this article, the NiCr∕NiSi thinˉfilm thermocouple is compared to the NiCrSi∕NiSiMg thin-film thermocouple in terms of static repeatability,service life and temperature limit,in order to better adjust measures to local conditions.And a compare test was done with a thin-film thermocouple produced by a university in Dalian,verifying the important role of the process on the properties of thin-film thermocouples.Thin-film thermocouples as a new type of thermocouples have a wide application prospect for surface temperature measurement of engine blades and other special parts.?

Abstract:Based on different structures，the dual range pistons can be divided into dual piston pressure vacuum gauges and dual piston gauges. According to the structural characteristics of the dual piston gauge, we analyzed the case when two piston-cylinder systems used only one set of weights. The actual pressure value under nominal value was calculated according to the quality of the weights and the parameters of the piston. The results show that the accuracy grades can be divided according to the different pressure ranges,to achieve the piston gauge traceability calibration and ensure the accuracy and consistency of pressure field.?

Abstract:The design principles and manufacturing technology of AC standard resistors, including measuring technique and testing methods,have attracted more and more attention from all walks of life.The function and testing technology of traditional DC resistors cannot take the place of the function and measuring method of AC resistors,and are not suitable for the assessment of the resistance of AC resistors.With the development of the science and technology,all domains involve the correctness and reliability of AC resistance values,which have direct bearing on the assessment of product quality and valid use. This paper focuses on the impact of several factors affecting the quality of AC standard resistors to make some preliminary analysis.?