Abstract: In order to cailibrating the non combustible test device of building materials and ensure the accuracy and reliability of test results, the temperature distribution model of the test device was studied, a set of dynamic calibration equipment for building material non-combustibility test furnace is designed and developed. The device adopts thermocouple high temperature detection and temperature compensation technology to realize the dynamic temperature detection of the test furnace, and the Servo Motor and sliding platform are designed to realize the sensor automatic positioning in the high temperature furnace, using LabVIEW data processing technology and touch screen design to achieve calibration data processing and calibration results output. The developed calibration device has been tested, and the measurement performance meets the design requirements. The verification results of the calibration of various parameters of the test furnace are within the range specified in the standard, and the calibration uncertainty meets the requirements of quantity value transmission.
Abstract: To discuss the establishment and application of control charts, through an example of the stability assessment of gas flow standard facility by means of critical flow venturi nozzles. Firstly, range control chart (R chart) is established based on the statistical control limit. Then, average control chart ($ \overline x $ chart) is established after the confirmation that the R chart is in a controlled state. And the analysis of control charts is further conducted. Starting from the angle of the requirement of the stability assessment, target control limits of the $ \overline x $ chart are determined. The calculation method of control limits of the $ \overline x $ chart is different from the method stipulated in JJF 1033-2016 Rule for the Examination of measurement Standards. Control charts can monitor the changes of Standard values provided by the measurement standard; therefore, it can judge the stability of measurement standard according to the requirement of the stability assessment intuitively and accurately. Meanwhile, it can provide early warning of possible uncontrolled quality to ensure the stability of measurement standard.
Abstract: This article combines IoT technology to design a coal test data transmission system based on LabVIEW. This system consists of hardware and software. The hardware uses two -level data processing method to reduce the resource share. The laboratory data from the instrument serial port is sent to the second level for data processing through the first level of the system. The data format required by the database is sent to the cloud database through the network interface. The main function of the software is to view and save data to initialize the lower machine. Through testing the experiment in the laboratory environment, the results show that the system can upload data in real time and accurately. This system is helpful for solving the time and accuracy of the data of the coal quality test instrument in the traditional thermal power generation industry. This system has good application prospects.
Abstract: The development and application of hand-held laser-induced breakdown spectrometer are introduced in this paper. At present there is no special calibration specification for this kind of equipment. So the calibration method of hand-held laser-induced breakdown spectrometer is proposed. The main metrological characteristics include detection limit, indication error and repeatability. Based on the actual test data, the corresponding technical indexes are given. The uncertainty of indication error is analyzed in detail and the corresponding evaluation example is given. An effective evaluation method for the metrological traceability of hand-held laser-induced breakdown spectrometer is given.
Abstract: With the increasing number of motor vehicles, exhaust pollution has become the focus of attention. How to scientifically control the excessive emission of motor vehicle exhaust pollutants and strengthen the detection of motor vehicle exhaust are very important. The remote sensing measurement system of vehicle exhaust combined TDLAS technology、DOAS technology and automatic identification technology can on-line remote sensing measure exhaust pollutant concentration on the vehicle driving process that do not need to stop. In order to fulfill the requirements of Calibration Specification numbering JJF1835-2020 for The remote sensing measurement system of vehicle exhaust, a new auxiliary device for calibration has been developed. The device is used for static and dynamic calibration of gas measurement indication error with standard gas and has achieved good results. This paper introduces the working principle, device composition and software and hardware design of the auxiliary device for gas calibration comprehensively.
Abstract: Point at present situation of measuring small pulling forcegauge inmetrological service,small pulling forcegauge calibration device was developed,so some matterswhensmallpulling forcegauge is measured usingWeight,for example ,heavy working intensity,unablezeroed and full scale range cannot be measured ,can be solved.
Abstract: Aiming at the problems of low efficiency, accuracy and poor reproducibility in manual measurement of weight quality, the work flow of weight measurement, the stability of mass comparator, the motion control of three-dimensional manipulator and the positioning accuracy of loading and unloading are studied. The basic principle of PLC servo control system is analyzed, and a set of control system of weight automatic verification device based on PLC is designed and developed. Taking CX programmer as the development platform, the control system is established by using PLC and ladder diagram programming language. The automatic control of the whole process of weight loading and unloading and the automatic detection of weight quality are realized. The overall debugging and experimental verification of the system are carried out. The results show that the control system has the advantages of simple structure, high efficiency and avoiding human error, and improves the automation level and reliability of weight verification.
Abstract: The influence factors of the measurement error of fuel dispensers mainly come from ambient temperature, flow rate of oil gun, standard metal gauge and oil and gas recovery system. In this paper, the effects of ambient temperature, flow rate of oil gun, standard metal gauge and oil and gas recovery on the error of indication value of fuel dispensers are analyzed through multiple groups of comparative experiments. Experiments show: the verification volume of standard metal gauge is lower than the actual volume when the gasoline temperature is lower than the environment temperature in summer. However, the verification volume of standard metal gauge is higher than the actual volume in winter. The error value will be bigger in the large velocity. Due to the volatility of gas is caused by the structure of standard, different standard shows different error value. It will gives less oil when the gas recovery is activated. The larger the gas liquid ratio is, the bigger the error value is.
Abstract: Low field nuclear magnetic resonance has gradually become the mainstream method for measuring solid fat content, which is an important index to qualify cocoa butter, margarine and other oils because it is simple, rapid and solvent free. However, Low field nuclear magnetic resonance direct method is a relative method, which requires the instrument to be calibrated using a glycerol trioleate/glycerol tristearate mixture. In this paper, the development and the principle of Low field NMR are introduced, the traceability and the stability of the glycerol trioleate/glycerol tristearate solid fat content reference material are studied, the measurement in different temperature are compared and the determination of the value was confirmed.
Abstract: Organic analysis is an essential part of chemical metrology, and is closely related to food, clinical and environmental sectors. Organic Analysis Working Group (OAWG) is one of the nine technical working groups under the Consultative Committee for Amount of Substance: Metrology in Chemistry and Biology (CCQM), International Committee for Weights and Measures (CIPM). In December 2020, OAWG issued the Strategic Plan for 2021~2030. Learning the strategy of OAWG is of great importance to understand the status of global organic chemical metrology, follow international development trends and provide reference for strategic planning in China.
Abstract: Salofamide mesylate is mainly used to treat Parkinson's disease. A LC/MS method was developed for the determination of genotoxic impurities ((S) - 4 - ((1-amino-1-oxopropane-2-methyl) amino) methyl) in safinamide mesilate. The sample was dissolved in methanol, separated on YMC-Triart C18 column (4.6mm×100 mm, 3μm), mobile phase: water (containing 0.1% formic acid) -methanol (containing 0.1% formic acid), gradient elution, and finally detected with a mass spectrometer detector. Under the condition of selected chromatography, genotoxic impurities can separate well. The LODs was 0.76 mg/kg and the LOQs was 1.53 mg/kg. Standard recovery rate was 98.5%～99.90% with relative standard deviations of 0.83%～2.10%. The linear response range was between 1.53～30.54 ng/mL (R2 >0.99). The results showed that the method was sensitive, accurate, reliable and suitable for screening of genotoxic impurities ((S) - 4 - ((1-amino-1-oxopropane- 2-methyl) amino) methyl) in safinamide mesilate.
Abstract: Tungsten telluride magnetoresistive material is famous for its unsaturated magnetoresistance effect. Information storage and the manufacture of magnetic sensor devices based on this also represent an important direction of magnetoresistance research. The doping method can change the magnetic and electrical properties of the material. In order to explore whether tungsten telluride magnetoresistive materials can obtain excellent performance through silver doping, a detailed analysis of how to choose the doping method and why choose silver as the doping element is discussed. And a method for the gentle preparation of bulk silver-doped tungsten telluride magnetoresistive materials is established. A new self-service flux sintering method is used to prepare three typical silver-doped WTe2/Ag materials. The characterization and evaluation of phase, valence state, structure, and accurate measurement of magnetoresistance performance have obtained. These results indicate that the excellence of the silver doping method which is selected, the prepared WTe2/Ag not only has reliable material quality, but also effectively improves the magnetoresistance effect, which make it easier to realize the control conditions when testing the highest value. The measured magnetoresistance is 502.3% at 5 K and 14 T, which is 50% higher than undoped. The magnetoelectric performance is greatly improved by compared with other elements, which is of positive significance for the optimization design and practical application of electromagnetic devices.
Abstract: High purity α-arbutin reagent was used as raw material which was further identified and confirmed by MS/MS, IR, UV-vis, nuclear magnetic resonance, melting point, optical rotation, etc.. The chromatographic purity of α-arbutin reference standard was determined by high performance liquid chromatography (HPLC) coupled with fluorescence detector (FLD). Moisture and ignition residue determination were carried out according to the guideline specified in Volume IV of the Pharmacopoeia of the People's Republic of China 2020 Edition, respectively. The residual solvents were determined according to the procedure specified in the Safety and Technical Standards for Cosmetics. The purity of α-arbutin reference standard was then calculated by mass balance method and the certified value of α-arbutin is 99.87% with an expanded uncertainty of 2.46% (k=2). Homogeneity and stability tests were carried out with HPLC-FLD after packaging. The α-arbutin reference standard with a high purity, accurate value and stability can provide technical support to cosmetics quality and safety tests in China.
Abstract: Digital PCR (dPCR) is an absolute quantitative technique of nucleic acid, which is widely used in transgenic and gene detection. In order to ensure the accuracy and reliability of digital PCR measurement results in China, 16 laboratories were tested using transgenic plasmid DNA samples. The comparison results showed that the difference between the ratio of foreign gene to internal copy number (<25%) to evaluate the measuring ability of the laboratories. The 16 laboratories were all within the acceptable range, and there was no significant difference among different digital PCR platforms. Due to the influence of plasmid conformation, the absolute copy number content of plasmid DNA measured in 7 laboratories was significantly lower than the reference value. It is suggested that when using digital PCR for quantitative measurement of plasmid DNA copy number, it should be confirmed whether the conformation of plasmid has an effect on amplification.
Abstract: In July 2021, the Consultative Committee for Amount of Substance: Metrology in Chemistry and Biology (CCQM) issued the Strategy Document for 2021-2030, delivering its mission of advancing the global comparability of chemical and biological measurement standards and capabilities. This article summarizes the highlights of the Strategy Plan, with an aim to learn about the priorities of future development, underpin strategic planning in China as well as optimize the structure and mode of international cooperation to boost the development of metrology in chemistry and biology in China.
Abstract: Hollow shaft angle encoder automatic calibration was achieved using a continuous full-circle angle standard developed by the National Institute of Metrology as a standard angle generator, a two-dimensional slideway clamping system to fix the encoder stator, and data acquisition software based on the LabView development platform. The clamping system tackles with the manual positioning difficulty due to high starting torque and provides continuous automatic calibration in the 360° full-circle range, which improves the testing efficiency and reduces the sources of uncertainty. The encoder repeatability is better than 0.8″ after using clamping system.
Abstract: The dialysate concentration is generally expressed by the dialysate conductivity monitoring value, and its accuracy and stability are the guarantee for the patient to achieve adequate dialysis treatment. According to the national metrology technical specifications, use the hemodialysis machine detector to test the conductivity parameters of the hemodialysis machines in the medical institutions in the province. The results showed that the qualified rate of hemodialysis machine conductivity parameter detection was 99.9%. By analyzing and discussing the causes of conductivity inaccuracy, it can provide reference for the clinical management of hemodialysis machines in hospitals at all levels, and improve the quality assurance capability of medical equipment.
Abstract: The accuracy of the dry biochemistry analyzer has a direct impact on the clinical diagnosis results. In view of the lack of its calibration specifications, the calibration specifications are formulated. Through the analysis of the technical principles and calibration methods of the dry biochemistry analyzers, the main measurement characteristics and specific calibration methods were determined, and a representative dry biochemistry analyzer model was selected for experimental verification. According to the calibration method, the verification result of the dry biochemistry analyzer meets the requirements of the determined measurement characteristics. The "Calibration Specification of Dry Biochemistry Analyzers" was successfully formulated, which promoted the standardization and standardization of the traceability of the dry biochemistry analyzers.
Abstract: The general characteristics of the threaded connection of inertial devices are small size and high assembly accuracy.In this paper,a set of small-size screw tightening test device is developed to solve the problems of large pre-tightening force error and low control precision during the assembly process of small-size screws. Through the tightening process experiment of TC4 titanium alloy screws, the influence of the tightening strategy on the value and dispersion of pre-tightening force is analyzed, including torque-control method and angle-control method.The influence of threshold torque and step by step tightening on pre-tightening force is further studied. The results show that angle-control method can improve the control preload precision by about 7% compared with torque-control method. The selection of threshold torque of angle-control method has great influence on the consistency of preload. Step by step tightening can improve the control precision of torque-control method and angle-control method on pre-tightening force.
Abstract: In mmwave technology a low frequency is always multiplied to generate a much higher frequency. Phase noise will be also increased and phase noise test will be more important in mmwave band. It is limited with spectrum analyzer method because of some reasons. And phase noise analyzer can only cover up to 50 GHz in a single unit. After the basic introduction of phase noise test technology in mmwave band two external mixer method is provided. Result shows that with this method we can get a stable test result.