In recent years, some studies have shown that the rapid and accurate measurement of body temperature is conducive to the early detection of patients ' diseases, such as fever and respiratory syndrome. In this paper, a 24-hour continuous monitoring of human body temperature is designed for hospitals and other medical places. The body temperature monitoring module is designed to have multiple measurement sites and can upload data to the system. Combined with the application system functions, it provides users with 24-hour real-time monitoring services, as well as data analysis and early warning functions, so as to timely remind users of abnormal changes in body temperature. The test shows that the designed intelligent body temperature monitoring system has high sensitivity and long use time, which can ensure the stable transmission of data.
The medical trace element analyzer is used to measure the content of lead, cadmium, copper, zinc, calcium, iron, magnesium and other substances in the human body. This article selects two or more national standard substances of lead, cadmium, calcium, zinc, iron, copper and magnesium with different concentrations and manufacturers for experiments, and analyzes and studies the metrological calibration method of the medical trace element analyzer based on atomic absorption method. Mainly referring to the national metrological verification regulation JJG694-2009《Verification Regulation for Atomic Absorption Spectrophotometers》, through testing medical trace element analyzers from multiple manufacturers, the metrological characteristics of detection limit, repeatability, and linear error were analyzed, and mathematical models were provided. The effectiveness of the calibration method was verified using linear regression and uncertainty evaluation methods. The most typical calcium element was selected for data analysis. The linear correlation coefficient R2 in the linear regression analysis was 0.999, the slope of the linear equation was 0.985, and the extended relative uncertainty of the calibration result was 2.2% (k=2).
Research on the measurement performance testing of electronic temperature and pressure correction diaphragm gas meters. The output volume of the base meter counter is converted into electronic readings through electromechanical signals, and then temperature and pressure values are collected to convert them into standard electronic readings. During dynamic testing, the electronic reading has a high refresh rate and is delayed in time, making it impossible for the flow standard device to perform dynamic sampling. To solve the sampling problem, when the cumulative value is greater than or equal to the pulse equivalent, the LED flashes and outputs a photoelectric signal, which is sampled by the flow standard device. There is another issue where the mantissa cannot be identified, which directly affects the accuracy of error testing. A sampling method using optical interfaces and communication protocols is proposed to accurately read the standard volume value of a gas meter. This article discusses its implementation, circuit structure, and error calculation method. By constructing a testing environment with a gas temperature of 40 ℃ and a gauge pressure of 15kPa, the G4 electronic temperature and pressure correction diaphragm gas meter qma error is tested using a 0.5 level sonic nozzle standard device. Compared with traditional testing methods, the difference in qma error is less than 1/5MPE, Verify the accuracy of the testing method and meet the requirements of fast, accurate, and efficient testing.
With the development of neutrons and related technologies, neutron metrology is also constantly developing. Traditional neutron reference fields are mainly based on isotopic neutron sources for calibration work. With the advancement of small neutron generator technology, establishing neutron fields based on neutron generators has received attention. This study focused on determining the yield of a deuterium-deuterium (DD) neutron generator, which used the indium foil activation combined with Monte Carlo simulation. According to the yield measurement results, its neutron ambient dose equivalent rate was calculated and compared with the measurement results of a neutron dosimeter. The results showed good agreement between the two data, thereby verifying the accuracy of the yield measurement results.
The sunlight simulation system for the whole vehicle test environment chamber is mainly used for automotive air conditioning performance testing, automotive fuel consumption testing, and electric vehicle range testing. Its performance directly affects the results of the whole vehicle test inspection. This article refers to the requirements of domestic and foreign automotive testing standards and proposes a calibration method for the vehicle testing environment chamber sunlight simulation system. Two calibration cases of the heavy-duty vehicle testing environment chamber sunlight simulation system are provided, and the optimization possibility of this method is further analyzed to provide reference for its calibration.
Basing on ground test conducted in contemporary aircraft development, expounded the testing requirements, testing methodology and the data processing and application about temperature parameter. Reported the traceability and status of metrology management about temperature test equipment. Focusing on the contributing factors about temperature measurement and calibration, analyzed requirements definition of testing parameter, testing procedure and calibration procedure. Looked forward to the scenario of leading edge of temperature test applied to aircraft development and concluded at last.
To address the challenge of on-site calibration of transformer winding temperature indicators, a precision portable calibration device has been developed. This device is designed with a modular structure, which integrates components for constant temperature, measurement, and excitation. This design reduces system complexity and minimizes errors. On-site calibration tests were conducted on various units of the winding temperature indicator, including the temperature display unit, contact switch unit, and thermal simulation unit. The calibration results indicate that the device can accurately measure and record the real-time temperature and contact actuation temperature of the winding temperature indicator, with an error of ≤ 0.1 ℃. It can control and measure the current required for thermal simulation, achieving an accuracy of 1mA at a corresponding temperature of 0.05 ℃, The calibration accuracy for temperature rise error of indication can reach 0.5 ℃.
On the basis of analyzing modern electronic equipments’ basic testability prediction flows, the problems existing in current testability prediction process are pointed out, and a kind of testability prediction method based on “concurrent engineering” thought and hybrid dependency models is figured out. In condition of ground securing and ground move, take the electronic equipment holding four fault class and three test assignment for example, the method is illustrated. Through taking method of integrating interval Bayesian networks and greedy algorithm, the testability prediction problem caused in case of test overlap is resolved. The method can be synchronous with equipments’ CAD, and promote the creditability of testability prediction result.
As a major energy consuming country, China's demand for natural gas usage has been increasing year by year. Pipeline transportation and ultrasonic flow measurement are the main forms of natural gas trade handover. With the commissioning and operation of the China Russia pipeline, China's use of natural gas has further increased. Small and medium-sized ultrasonic flow meters are gradually unable to meet the demand for natural gas trade handover, while large-diameter flow meters with a diameter of DN300 or more are not within the scope of mandatory national calibration, and their measurement performance cannot be determined. This article takes the DN600 ultrasonic flowmeter as the actual measurement object, explores the characteristics of high-pressure large-diameter gas flowmeter, studies its error performance, data repeatability, and data stability at different flow points, grasps the measurement performance, improves the trade handover ability, and fills the gap in domestic large-diameter flow measurement.
The key technologie breakthroughs are as follows:the design of collet structure adapted to multiple wrenchs, the design of overall mobile structure compatible with current device calibration, the design gripping force and gripping material of adapted to multiple wrenchs, the design of control system satisfying smooth operation.The torque set time of the device is less than 60 seconds by automation,while the time is 900 seconds by hand.The problem is resoled that the work of torque Wrench Value set by hand is time-consuming and laborious , high labor intensity,and low working efficiency,which is at the forefront in the metrology industry in China and offers good technical basis for fully automatic lot production inspection of torque wrenchs.
In practical measurement, in order to improve measurement efficiency, the small number of repeated measurements and limited sample data pose challenges to uncertainty assessment. This article focuses on the uncertainty assessment of coordinate measuring machine size parameters, and evaluates the uncertainty of coordinate measuring machine size parameter extremely small sample data based on grey model, and compares it with traditional assessment methods. The results indicate that the evaluation method based on grey model can achieve the accuracy level under small sample conditions, providing a new and effective way to improve measurement accuracy and efficiency.
As a strong measuring instrument for trade settlement, it is necessary to evaluate the uncertainty of measurement data of fuel dispensers . This article uses GUM method and MCM method to evaluate the uncertainty of measurement errors of fuel dispensers, compares and analyzes the results of uncertainty evaluation, and analyzes the impact of input quantity correlation. The results show that the MCM method has a wider range of applications than the GUM method, and it is more convenient to deal with the influence of input correlation. The evaluation results are more accurate and reliable, and it is more suitable for evaluating the uncertainty of measurement errors in fuel dispensers.
Abstract: This article compares and analyzes the similarities and differences, as well as the key points of evaluation, between the concepts, development history, evaluation criteria, and evaluation content of China Metrology Accredition and Laboratory Accreditation. From the perspective of metrology institutions, a review process was established. This article analyzes the risks and countermeasures encountered by metrological institutions in the evaluation process from the aspects of personnel control, facility and environmental control, equipment control and management, and traceability of measurement. It provides reference for metrological institutions to apply for China Metrology Accredition and Laboratory Accreditation qualifications.
On-site verification is an activity in which a metrology institution verifies the measuring instruments used by customers on site to meet their needs. It is an important form of value transfer and an important measure to ensure the accuracy and consistency of values. With the development of digital economy, on-site verification of metrology institutions faces opportunities and challenges of digital transformation. This paper focuses on the exploration and analysis and practical results of the digital transformation work of on-site verification of metrology institutions, including the pain points of on-site verification work, digital process design, digital architecture design, original record data application design and so on, in order to provide application reference for the digital transformation of on-site verification of metrology institutions
Abstract：The environmental monitoring system for pig farming has a decisive impact on the pig farming environment. However, the current environmental monitoring system for pig farms generally has a low level of informatization and intelligence. This article designs a wireless sensor network-based environmental monitoring system for pig farming bases. After the system starts running, it will drive the water quality collection, dust concentration collection, light intensity collection, and air quality collection modules to obtain environmental data, and then send it to the aggregation node through the Lora wireless sensor network. After receiving it, the aggregation node will complete the data frame packaging and send it to the backend control center. In this way, the environment of the pig farming base can be monitored through the PC end, and the mobile end can communicate with the backend control center in real time through methods such as camera and photography. After testing, it has been proven that the main advantages of the system designed in this article lie in its long transmission distance, stable communication, low energy consumption, and self-organizing network, which can well meet the environmental monitoring requirements of pig breeding bases.
Online calibration of flow meter is an important means to trace the value of non-detachable online flow meter in petrochemical, electric power and other industries. Based on the practice of online calibration of on-site flow meter in petrochemical enterprises, especially for steam flow measurement, which is characterized by high temperature, high pressure, and the inconvenience of disassembling primary measuring elements, adopting online calibration technology for traceability of measurement values is real-time, efficient, economical, and convenient.This paper summarizes the main factors that affect the accuracy of on-site meter value, the basis and steps of online calibration and the final treatment scheme.
The article introduces the establishment of the metrology laboratory of γ ray of protecion level.The physical experimental method is used to measure the radiation field indicators of a 60Co (3700GBq)
single source device.Firstly,Verifying the inverse square law of dose distance, and then measuring the field diameter, uniformity, and scattering proportion at a distance of 3 meters from the radiation source.The results show that the maximum deviation for the inverse square law verification is 1.12%，the field diameter with a uniformity greater than 95% is 61cm，the scattering is 0.6%.The inverse square law,field diameter,field uniformity, and scattering of the radiation field all comply with the requirements of GB/T12162.1-2000 and the design specifications,and the owner successfully completed the establishment of γ radiation measurement standards.
Abstract: The purpose of intermediate checks is to determine whether the measurement standards, reference materials, or other measuring instruments maintain their original status. The validity of the verification status of measurement standards, reference materials, or other measuring instruments directly affects the validity of the certificates issued using these measuring instruments. Implementing intermediate checks on measurement standards, reference materials, or other measuring instruments can not only effectively control the measurement standards and measuring instruments but also effectively control the verification or calibration processes conducted using measurement standards and the testing processes conducted using measuring instruments, thereby ensuring the accuracy and reliability of verification, calibration, and testing results. Taking the intermediate check of a Class 0.02 digital pressure gauge as an example, this article elaborates on the process of using control charts to prepare operating instructions, demonstrate the form of intermediate check records, create control charts, and compile intermediate check reports for the intermediate check of Class 0.02 digital pressure gauges.
In metrological verification activities, the rule of simply making a pass/fail decision in conformity assessment of measuring instruments is commonly used. Due to the influence of measurement uncertainty in a test result, there is a significant risk for making incorrect decisions (risk of false acceptance or risk of false rejection) when the test result is close to a tolerance limit. This paper quantitatively assesses the possible “risks” of erroneous conformity decisions, discusses the relationship between the risk and measurement capability index , and provides an effective way to optimize conformity assessment methods and reduce the associated risk.
Abstract: To ensure the accuracy and reliability of measuring standards and equipment between two verifications or calibrations, and to maintain a well-trusted state of verification and calibration, it is essential to conduct intermediate checks on measuring equipment. Implementing intermediate checks on measuring standards, reference materials, or other measuring instruments can not only effectively control the measuring standards and instruments but also effectively control the verification or calibration processes using the measuring standards and the testing processes using the measuring instruments, thereby ensuring the accuracy and reliability of the verification, calibration, and testing results. Taking the intermediate check of temperature indication for platinum resistance sensors in an automatic temperature field testing system as an example, this article elaborates on the process of compiling the operation manual, the form of intermediate check records, the intermediate check graph, and the intermediate check report for the temperature indication of platinum resistance sensors in an automatic temperature field testing system. After each verification, the graph should be inspected for any occurrences where the values exceed or approach the control limits, and further corresponding measures should be taken based on the actual situation.
Because of its special steady-state properties, bistable structures have received extensive attention in the field of mechanics research. As a typical two-dimensional bistable structure, thin-walled open cylindrical shell structures have high application potential in aeronautics and aerospace as well as other fields. A theoretical model of the structure was established based on the classical anisotropic elastic theory of composite materials mechanics and the principle of minimum potential energy, and the finite element simulation method was used to analyze the bending behavior and mechanical properties of the thin-walled open cylindrical shell structure. Also the influence conditions of the bending radius and steady state force of the structure were studied, and the experimental verification was carried out. Finally, the application of the bistable structure in the typical aircraft structure is proposed based on the characteristics discussed above, since it has the advantages of light weight, good maintenance and low complexity, which provides a guide for the design of the new aircraft structure.
The load spectrum measurement is an important work in the process of aircraft life determined and extension. The resistance strain measurement method is widely used in the current load spectrum measurement. Compared with other methods, this method has its own advantages, especially in the aircraft load measurement test which is different from the strain test. In this paper, based on the traditional resistance strain test method, a Wheatstone bridge test scheme is designed to test the aircraft flight load, and the key technology of attaching and installing the strain gauge is proposed, which provides a reference for the aircraft load spectrum test process. The correctness and accuracy of the design scheme are verified by taking the wing load test of a certain type of aircraft as an example, and the results show that the measured load data are real and reliable.
IIn the stage of civil aviation engine research, the design state iteration is fast, the characteristic parameters are many, and the structure of the measuring part is complex. As an important geometric measurement tool, engineering coordinate measurement results are often used as an important basis for product design change/airworthiness manufacturing compliance review. However, the lack of measurement ability, the inconsistency of measurement results and the long training cycle of measurement engineers greatly restrict the development progress of the product. In this paper, engineering CMM management of manufacturing process is proposed: According to the CMM requirements of aero-engine engineering in the scientific research stage, the key measurement items are decomposed, the measurement comparison method is introduced, the measurement comparison assessment mechanism is established, the ability of engineering CMM personnel in manufacturing process is controlled and evaluated, and the purpose of rapidly improving the measurement level of personnel is realized. In addition, establish the physical verification, accounting and change mechanism of the measurement program, decompose the same family measurement process, improve the reliability of the measurement program on the basis of measurement efficiency, and ensure the measurement quality of the engineering three coordinates. Since the operation of the system, the measurement problems of field measurement personnel have been significantly reduced, and the consistency of measurement results has been improved, which has the practical conditions for further popularization and application to the manufacturing process of aero engine supply chain.
With the increase in sewage discharge and the advancement of water quality standards, upgrading existing sewage treatment plants is necessary to enhance production efficiency and ensure stable effluent water quality. Using a specific project as an example, this paper designs an optimization scheme for the control system based on the operational conditions of the sewage treatment plant. By analyzing the control requirements of both regulating tanks and anaerobic/aerobic (A/O) tanks, we propose adaptive flow control schemes and fuzzy PID-based dissolved oxygen control schemes that are applied to actual plant production. The results demonstrate that our system operates effectively with stable effluent quality meeting regulatory standards.
