As an important component of the new energy vehicle field, fuel cell vehicles are powered by the process of hydrogen gas passing through fuel cells to generate electricity. The quality of hydrogen directly affects the efficiency and lifespan of fuel cells, therefore ensuring the high quality of hydrogen is crucial. This article comprehensively explores the relationship between fuel cell vehicles and hydrogen quality, existing hydrogen quality detection technologies and their limitations, and focuses on several new rapid detection technologies, including hydrogen sensor technology, spectral analysis technology, and mass spectrometry analysis technology, as well as their applications in hydrogen quality detection of fuel cell vehicles.

With the rapid development of technology, traditional building material testing methods face many challenges, such as low efficiency, high cost, and insufficient accuracy. Therefore, introducing intelligent technologies such as artificial intelligence, machine learning, and the Internet of Things has become a key way to improve the efficiency and accuracy of building material detection. Artificial intelligence algorithms can achieve intelligent recognition and evaluation of building materials through a large amount of data learning and training, thereby improving the accuracy and speed of detection. At the same time, the application of Internet of Things technology makes the process of building material testing more intelligent and automated, achieving real-time monitoring and data transmission. In addition, the application of machine learning algorithms has also provided new ideas and methods for building material detection, further improving the accuracy and reliability of detection through deep data analysis and pattern recognition. Therefore, applying intelligent technology to material testing in construction projects is expected to bring revolutionary changes to the construction industry.

Objective To establish a highly specific method for thedetermination of related substances in salbutamol sulfate injection. Methods HPLC was performed on a column packed with spherical end-cappedoctylsilyl silica gel (Hypersil BDS C8 ${4.6}\times {150}\mathrm{\;{mm}},{3\mu}\mathrm{m}$ ) at the flow rate of ${0.6}\mathrm{\;{mL}}/\mathrm{{min}}$ , thedetection wavelength of ${220}\mathrm{\;{nm}}$ and columntemperature of ${25}^{\circ }\mathrm{C}$ by gradientelution using ${3.45}\mathrm{\;g}/\mathrm{L}$ sodiumdihydrogen phosphate dihydrate solution (adjust to $\mathrm{{pH}}$ 3.0 with phosphoric acid)as mobile phase A, 10 volumes of methanol and 90 volumes of acetonitrileas mobile phase B. Results The chromatograph showed good specificity ofthe peaks of main components and 15 impurities, and the methodverification of 6 of the impurities showed good linear, repeatabilityand recovery. Conclusion The chromatographic peaks of the maincomponents in salbutamol can be completely separated from the 15impurities. The established method is highly specific, easy to operateand can be used for the inspection of related substances in salbutamolsulfate injection.

Objective To evaluate the application value ofhigh-performance liquid chromatography fluorescence detection method fordetermining nitrite in drinking water. Method Collect mineral water, tapwater, and source water as water samples, and use high-performanceliquid chromatography fluorescence detection method to determine.Analyze the detection advantages of this method and the stability ofnitrite derivative 2,3 naphthalene triazole in the water standard. Result The nitrite concentration detected in pure water was ${0.6\mu }\mathrm{g}/\mathrm{L}$ , with goodpeak shape and no impurity interference; The detection limit ofhigh-performance liquid chromatography fluorescence detection method is ${0.3\mu }\mathrm{g}/\mathrm{L}$ , andthe quantitative limit is $1\mathrm{{\mug}}/\mathrm{L}$ ; After derivatization with nitrite, thestability of the derivative is high, and the measurement error is smallwithin 7 days; The recovery rate of nitrite spiking is between90.29%-102.60%, and the precision is between 0.71%-3.66%. Conclusion Thedetermination of nitrite in drinking water by high-performance liquidchromatography fluorescence detection method has the characteristics ofaccuracy and convenience, providing important technical support fordrinking water safety monitoring.

Objective To optimize the detection method and explore thedetection method with stable strength data and small relative standarddeviation of Curdlan. Method Using Curdlan as the material, compare theglue making methods, optimize the sampling amount, heating temperature,ice water bath cooling time, and parallel measurement times based onsingle factor experiments, and analyze the optimal combination of eachfactor condition through orthogonal experiments. Result The determineddetection method is to take a sample of ${0.30}- {0.31}\mathrm{\;g}$ , add ${15}\mathrm{\;{mL}}$ of freshly prepareddegassed water, stir with a trace sampling spoon to evenly disperse thesuspension, heat in a boiling water bath and maintain its uniformity,heat in a water bath for 10 minutes, then remove and cool in an icewater bath for 50 minutes, and conduct three parallel experiments. Conclusion This method has a small relative standard deviation andstable data. The column heads with diameters of ${0.4}\mathrm{\;{cm}},{0.5}\mathrm{\;{cm}}$ and ${0.6}\mathrm{\;{cm}}$ forproducts with gel strength greater than ${600}\mathrm{\;g}\cdot {\mathrm{{cm}}}^{-2}$ can be used for determination.

Objective A method was developed for the simultaneous determination of calcium, boron and sodium in Bombyx batryticatus by Inductively coupled plasma mass spectrometry (ICP-MS). Methods Microwave Digestion was used as the pretreatment method. The contents of Ca, B and Na in 25 batches of Bombyx batryticatus were determined by ICP-MS and analyzed by multivariate statistics. Results The three elements had a good linear relationship (r>0.995), the recoveries were in the range of 80%~120%, the reproducibility RSD<5%, the reproducibility RSD<5% and the stability RSD<5% within 1 day. Conclusion the method is simple and accurate, and can be used for the quantitative study of three elements in Bombyx batryticatus. The results can provide reference for the quality control and origin study of Bombyx batryticatus.

Objective To establish a new liquid chromatographic methodfor caffeine content in milk tea, to detect the caffeine content ofinstant milk tea in the region, and to make recommendations on healtheffects. Methods The determination was carried out on a Waters highperformance liquid chromatography Symmetry C18 column $\left({{5\mu}\mathrm{m}\times {150}\mathrm{\;{mm}}\times {4.6}\mathrm{\;{mm}}}\right)$ ,the mobile phase was methanol-water $\left({{30}+ {70}}\right)$ at a flow rateof $1\mathrm{\;{mL}}/\mathrm{{min}}$ ,the detection wavelength of ${272}\mathrm{\;{nm}}$ , and the columntemperature was ${35}^{\circ }\mathrm{C}$ . Results Thecorrelation coefficient was $\mathrm{r}={0.9999}$ over the linear range of 1-30 μg/mL, the recoverieswere 97.2%-99.5%, and the method precision was ${0.54}\%$ . Conclusion The method adoptspotassiun ferrocyanide and zinc acetate precipitation centrifugation,which can rapidly extract the effective components of caffeine in milktea and remove the interference of proteins, shorten the pretreatmenttime, optimize the chromatographic conditions, and accelerate thedetection of caffeine.

Given the potential adverse effects of alcohol ether estercompounds in the air on the environment and public health, this studyaims to develop an accurate method for monitoring these compounds. Byanalyzing experimental data, this study selected suitable measurementmethods and instrument reagents, and established a detailed measurementprocess. The research results show that the optimized carbon disulfidedesorption gas chromatography method performs excellently in thequantitative analysis of alcohol ether esters, with a linearrelationship of over ${99.9}\%$ and adetection limit as low as ${0.02}\mathrm{{mg}}/\mathrm{L}$ . Inaddition, the relative standard deviation of this method in precisionand recovery tests is less than 5%, fully demonstrating its highreliability and application value in environmental monitoring.

Objective To establish an HPLC method for the simultaneousdetermination of 12 common bacteriostatic agents (benzoic acid, benzylalcohol, sorbic acid, methylparaben, thimerosal, ethylparaben,chlorhexidine acetate, propyl hydroxybenzoate, butyl p-hydroxybenzoate,benzalkonium bromide, domiphen bromide, benzalkonium chloride ) inbrimonidine tartrate eye drops. The 48 batches of samples collected from4 domestic manufacturers were tested and evaluated. Methods ShiseidoCAPCELL PAK C18 MGII column ( ${4.6}\mathrm{\;{mm}}\times {250}\mathrm{\;{mm}},{5\mu}\mathrm{m}$ ) was used, ${0.02}\mathrm{\;{mol}}/\mathrm{L}$ ammonium acetate(pH adjusted to 4.5 by glacial acetic acid)(mobile phaseA) and methyl alcohol(mobile phase B) were used for gradient elution,and the detection wavelength was ${262}\mathrm{\;{nm}}$ . Results Theseparation degree of 12 bacteriostatic agents reached the requirements,and the blank excipients did not interfere with the determination ofbacteriostatic agents, the linear relationship of bacteriostatic agentsin their linear range was good, the average recoveries were in the rangeof 92.8% to 105.7% and the RSDs were ${0.3}\%\sim {1.9}\%\left({\mathrm{n}=9}\right)$ . The qualitative analysis showed that the types ofbacterial inhibitors in 48 batches were all in agreement with theformulation. The quantitative determination showed that the contents ofbacterial inhibitors were between ${24}\%\sim {102}\%$ of the formulation. Conclusion The method is sensitive, rapid and specific, and can be usedfor the accurate quantitative determination of multiple bacteriostaticagents in brimonidine tartrate eye drops. This study can providetechnical support for the standardized use of bacteriostatic agents inthis variety.

Objective A method for the determination of fluoride ion incoalmine water was established by ion chromatography. Methods The watersamples were determined by ${0.22\mu}\mathrm{m}$ qeuosystem filter membrane with a volume of ${25\mu }\mathrm{L}$ . In ion chromatograpy,the determination of fluoride was completed within $4\mathrm{\;{min}}$ under the anionexchange chromatography of HS-5A-P3 with column temperature at ${35}^{\circ }\mathrm{C}$ , eluted with ${20}\mathrm{{mmol}}/\mathrm{L}\mathrm{{KOH}}$ solution at the rate of ${1.0}\mathrm{\;{mL}}/\mathrm{{min}}$ . Results The linear relation between peak area and concentration offluoride were good. The linear return equation was $\mathrm{y}= {30.26}\mathrm{x}- {0.104}$ .The correlation coefficient of the standard curve was above 0.9997 . Thedetection limit was ${0.002}\mathrm{{mg}}/\mathrm{L}$ . Therecovery of fluoride was ${88.0}\%$ -115.5%. The mean value offluorine ion content in the standard sample was within the range of itsguaranteed concentration. Conclusion Compared fluoride ion selectiveelectrode method, the method has the advantages of small sample amountand can be used to determine other components simultaneously. It issuitable for the determination of fluorine ion content in largequantities of coal mine water.

Objective To establish a method for benzo[α]pyrenedetermination in prepared Radix Rehmanniae by molecularly imprintedsolid phase extraction coupled with ratio fluorescence detection. Methods The molecularly imprinted polymers (BaP-MMIPs) were prepared bysol-gel method using dendritic-grafting magnetic nanoparticle as thesupporting material and benzo $\left\lbrack \alpha \right\rbrack$ pyreneas the template. Benzo[ $\alpha$ ]pyrene in the prepared sample wasseparated and enriched by BaP-MMIPs as dispersive SPE materials, and wasdetected by ratio fluorescence determination. The calibration curve wasobtained by measuring the fluorescence intensity ratios $\left({{\mathrm{I}}_{436}/{\mathrm{I}}_{604}}\right)$ of benzo $\left\lbrack \alpha\right\rbrack$ pyrene in different concentrations. ResultsBaP-MMIPs showed remarkable selectivity, high efficiency and stable,which were successful applied as solid phase extraction materials forthe trace benzo[a]pyrene determination in prepared Radix Rehmanniae.Good linearity was achieved in range of 0.14~3.0 $\mu \mathrm{g}/\mathrm{{mL}}$ . The LOD was ${80}\mathrm{{ng}}/\mathrm{{mL}}\left({\mathrm{S}/\mathrm{N}=3}\right)$ and LOQ was ${112.5}\mathrm{{ng}}/\mathrm{{mL}}\left({\mathrm{S}/\mathrm{N}={10}}\right)$ . The average recoveries of benzo $\left\lbrack \alpha \right\rbrack$ pyrenewere 89.5%-106.8% with the RSD≤3.6%. Conclusion The method is accurate,selective, high sensitive, reproducible, economical, simple and fast.The research has profound significance for the benzo[a]pyrene monitoringin Traditional Chinese Medicine.

With the increasing demand of laboratory teaching and scientific research in colleges and universities, higher requirements are put forward for laboratory safety education, which is also an important content to ensure the safety of teachers and students, great importance must be attached to it. In view of this, colleges and universities should pay attention to laboratory culture, actively establish a safety education system, do a good job of top-level design, establish a sound evaluation mechanism, and gradually optimize educational methods and methods, and then build an integrated safety culture and education system.

The re evaluation of qualification recognition capability is a capability confirmation work that inspection and testing institutions need to carry out every six years. The new version of the "Criteria for Qualification Recognition and Review of Inspection and Testing Institutions" has been officially implemented since December 1, 2023. This article mainly elaborates on how to efficiently pass the qualification recognition re evaluation work of inspection and testing institutions under the requirements of the new criteria. Taking a certain inspection and testing institution in Beijing as an example, this article briefly introduces the entire process of re evaluation, including organization preparation, online reporting, on-site audit, later rectification, and evidence collection. It provides a detailed analysis of the entire process of re evaluation and points out the precautions to be taken when preparing application materials for re evaluation. This provides a reference for the qualification recognition re evaluation application and related work of inspection and testing institutions.

With the application of surveying and mapping technology in land management, urban planning, resources exploration, environmental protection, disaster prevention and other fields in our country, the demand for surveying and mapping talents is strong, and the construction and management of surveying and mapping engineering laboratories in colleges and universities play an increasingly prominent role in personnel training. At present, the phenomenon of insufficient area of surveying and mapping engineering laboratories in colleges and universities, the updating and maintenance of instruments and equipment are not timely, and the management measures are not in place is more prominent. On the basis of analyzing the existing problems, this paper explores how to strengthen the scientific management of laboratory from the aspects of marking, placing, registration management, maintenance and repair of instruments and equipment.

There are problems with insufficient resource utilization, traditional experimental teaching content, and limited scientific research in experimental teaching laboratories and scientific research laboratories in universities. Opening up laboratories is the main way to improve the utilization of laboratory resources. Opening up laboratories is beneficial for enhancing students' innovative thinking and research abilities, promoting scientific research achievements among teachers and students, improving the utilization of laboratory resources, solving laboratory management problems, and promoting the implementation of industry university research work. This paper takes experimental teaching laboratories and scientific research laboratories in universities as research objects, elaborates on the problems of laboratory opening, analyzes the measures that should be taken for laboratory opening, and proposes the mechanism for opening experimental teaching laboratories and scientific research laboratories in universities.

The convergence of laboratory testing standardization and automation technologies has had a profound impact on scientific research and industrial applications. Standardization provides a framework for consistency and comparability, while automated systems improve experimental efficiency and reliability of results. This article will explore the importance of standardization of laboratory testing and its integration with automation technology, as well as the importance of compliance with standards for automated systems.

New requirements have been put forward for biosafety in the new era, and it is also listed as a top priority. Medical universities are the cradle of medical talents. Microbiology, as an important subject in basic medicine which combine the theory and practice. Based on the biosafety problems existing in microbiology teaching laboratories, it is extremely urgent to optimization. Through analyzing the current situation of microbiology teaching laboratory, this article mainly discusses the current situation and optimization of microbiology teaching laboratories. In line with student-centered teaching conception, contains the safety awareness of teachers and students, laboratory safety management, and existing safety risks, so as to improve the scientific and specification of microbiology teaching laboratories.

Safety is the basic guarantee for university laboratories to carry out teaching and research. The dual prevention mechanism with risk classification control and hidden danger investigation and management as the core can effectively curb the occurrence of laboratory safety accidents. This paper describes the four stages of building a dual prevention mechanism, and uses the operating condition risk assessment method (LEC) to evaluate and grade laboratory risks, moving the threshold of laboratory risk management and control to the risk point classification management and control, and building a solid laboratory safety defense line.

Smart laboratories play an important role in scientific research and production, however, they also face safety risks and management challenges. Building a smart laboratory safety management platform system can help laboratory managers comprehensively manage laboratory safety risks. In order to effectively manage the safety issues of smart laboratories, this study aims to build a comprehensive smart laboratory safety management platform system. By formulating the use of inspection equipment, the management of hazardous chemicals in the laboratory, the laboratory environment monitoring, and ensuring capital investment, a laboratory safety funding guarantee system is built. Through innovative applications of Internet of Things technology and other measures, the functions of the smart laboratory safety management platform system are realized, so that the safety and management efficiency of the laboratory are improved.

In response to the issues of inconsistent safety risk management standards, specialized level of safety management, and differentiated control in university laboratories, based on the concept of "full staff education, full process education, and all-round education", this paper proposes the use of information technology to promote laboratory safety classification and grading management measures. Multiple methods such as quantitative, qualitative, or comprehensive evaluation are used to evaluate the degree of risk that may be caused by hazards. Based on the practice of integrating the "Three Comprehensive Education" into the laboratory culture education system of our university, explore the information management mode of safety classification and classification in university laboratories.

This paper investigates the development direction, scale and new material inspection and testing ability of Chongqing's material industry, analyzes the current situation and existing problems of the new material inspection and testing industry, and puts forward the development path of focusing on the differentiated development of the testing industry and building a perfect testing public service sharing platform.

Microbial testing is of high importance in grassroots disease control centers. Effective microbial testing can ensure the disease prevention ability of grassroots disease control centers. In order to better implement disease control work, grassroots disease control centers attach great importance to the completion of microbial testing work. However, based on the completion of microbiological testing in some grassroots disease control centers in certain regions, there are still some omissions that have not been rationalized in the implementation process, which has had a certain impact on the application value of microbiological testing. Based on the consideration of the importance of microbiological testing in grassroots disease control centers, this article explores common problems and countermeasures in microbiological testing in grassroots disease control centers, in order to promote the improvement of microbiological testing accuracy. Targeted comprehensive analysis work is carried out from multiple aspects such as grassroots disease control center staff, equipment and instruments, and work environment, in order to achieve precise control and effective handling of related issues.

In the process of investigating ecological and environmental pollution cases, problems such as difficulty in identifying the attributes of unknown solid waste, complex identification processes, and slow identification time have always affected the efficiency of case investigation. Through personnel interviews, on-site investigations, and initial screening of on-site rapid detection equipment, comprehensive analysis is conducted to determine the detection indicators for the hazardous characteristics of unknown solid volatile organic compounds. The leaching toxicity and toxic substance content of volatile organic compounds are analyzed to identify unknown solid waste as hazardous waste. Accurate identification of hazardous characteristics greatly saves emergency inspection time and provides scientific basis for emergency disposal of unknown solid waste, improves case handling efficiency, and has guiding significance for similar ecological environment damage cases. At the same time, this article also studies the toxicity detection method of volatile organic compounds in solid waste.

Socialized environmental monitoring, as one of the important approaches for environmental monitoring in China, directly affects the effectiveness of our country's environmental protection efforts. However, at present, there are many quality issues in the socialized environmental monitoring data in China, which need continuous improvement and refinement. Therefore, this paper conducts an in-depth analysis of the existing data quality problems in the domestic socialized monitoring industry through literature research methods, clarifies the main factors affecting the quality of socialized environmental monitoring data in China, and proposes targeted countermeasures from the perspectives of optimizing management systems, improving personnel quality, and upgrading technical equipment. The research conclusions are of great significance for improving the socialized environmental monitoring system in China and enhancing the overall level of environmental protection in our country.

Objective To analyze the microbial detection results of drinking water in a certain area. Methods 77 water samples submitted for inspection in 2022 (including 60 for agricultural drinking water and 17 for urban drinking water) and 88 water samples submitted for inspection in 2023 (including 74 for agricultural drinking water and 14 for urban drinking water) were studied. The total number of bacterial colonies, total coliforms and thermostable coliforms were detected according to the Standard Inspection Method for Drinking water. Compare the relevant differences. Results (1) The qualified rate of microbial indexes in 2022 and 2023 was 73.94%; In 2022, 77 water samples were collected, and the total number of bacteria, total coliform, heat-resistant coliform and three comprehensive passrates were 62.34%, 58.44%, 58.44%, 58.44%, respectively. The total number of bacteria, total coliform, thermostable coliform and the comprehensive pass rates of 88 water samples in 2023 were 87.50%, 87.50%, 88.63% and 87.50%, respectively. The total qualified rate of agricultural drinking water in 2022 and 2023 is 56.67% and 60.81%. The total qualified rate of urban drinking water in 2022 and 2023 is 94.12% and 92.86%; In 2022 and 2023, the total number of bacteria, total coliform, heat-resistant coliform and three total pass rates of agricultural drinking water and urban drinking water were compared, and the difference was statistically significant (P＜0.05). Conclusion According to the results of sampling inspection, the qualified rate of urban drinking water is still not 100%, the qualified rateof rural drinking water is lower than that of urban drinking water, there are serious water pollution problems, relevant departments should strengthen the supervision of water quality in the future, and actively improve the disinfection work.

Objective In chemical analysis, the focus used to be on theprecision and accuracy of detection results. However, many testingactivities currently require establishing the credibility of theresults. Especially by measuring the credibility of the results to provetheir suitability, this generally includes the degree to which oneoutcome is expected to match other outcomes, which is also thesignificance of exploring uncertainty. Methods According to theCNAS-GL06 Guidelines for Evaluation of Uncertainty in Chemical Analysis,this article detected the content of phosphate ions in a certainindustrial wastewater and studied and analyzed the components thataffect measurement uncertainty during the experimental process. ResultsThrough calculation, it can be concluded that when the result ofphosphate ion is ${3.00}\mathrm{{mg}}/\mathrm{L}$ , theconfidence interval is ${2.86}-{3.14}\mathrm{{mg}}/\mathrm{L}\left({\mathrm{k}= 2}\right)$ . Conclusion The main factor affecting its measurement uncertainty is theuncertainty introduced by the calibration curve fitting. In order tomake the detection results more scientific and accurate, it is necessaryto pay attention to the maintenance and upkeep of the ion chromatographin daily work, minimize the background noise of the instrument, andimprove the sensitivity and accuracy of the instrument.

In order to accurately and efficiently determine the purityof ethyl acetate refined products, the separation was carried outaccording to the programmed heating method based on the analysiscondition of gas chromatograph. The initial temperature was set at ${80}^{\circ }\mathrm{C}$ , and after $4\mathrm{\;{min}}$ , the heating ratestarted at ${20}^{\circ }\mathrm{C}/\mathrm{{min}}$ ,and the termination temperature was ${140}^{\circ }\mathrm{C}$ . The analysisshowed that the separation degree of each peak was greater than 2.0, andthe peak shape was symmetrical, sharp and the baseline was stable.Effective separation is possible. After the quantitative analysis ofarea normalization method, correction factor method and internalstandard curve method, the correction factor method has thecharacteristics of high accuracy, strong stability and economy, and itis more suitable for the determination of ethyl acetate purity than thecorrection factor method.

Objective To analyze coal mine occupational health detection and occupational hazard prevention methods. Method The basic concepts of coal mine occupational health detection were expounded, the main methods and processes of occupational health detection were discussed, and occupational disease prevention and control strategies in technology and management were proposed. Results The incidence of occupational diseases in coal mines can be reduced through the comprehensive application of occupational health detection methods and effective prevention and control measures. Conclusion Coal mine occupational health detection and occupational hazard prevention are of great significance to protect the health of miners and improve the level of coal mine safety production.

Objective Exploring the effect of nicotinamide concentration on skin melanin transfer and its mechanism of action, to provide a scientific basis for the development and application of related skin care products and beauty technology. Methods The mechanism of nicotinamide inhibiting the formation of melanin was elucidated, and the main influencing factors of the formation of black spots were analyzed, so as to control the formation and transfer of melanin. The researchers then combined a variety of substances, including arbutin, phenylresorcinol, and vitamin C and its derivatives, to study. Results Nicotinamide was able to effectively inhibit the diffusion rate of melanin by blocking the transfer process of melanin particles to epidermal cells. When used in combination with arbutin, phenylethyresorcinol and vitamin C, its inhibitory effect is more obvious. Conclusion Niacinamide and its synergistic effect with other substances can effectively inhibit the transfer and diffusion of melanin, providing a new way for skin whitening. This discovery provides an important reference for the application and development of related skin care products and beauty technologies.

Ultrasonic flaw detector itself has the characteristics of high detection accuracy, fast detection speed, small size, light weight, and its own ultrasonic non-destructive testing, so it has been widely used in many fields. The measurement accuracy of ultrasonic flaw detector has a non-negligible impact on its function, and it will be affected by various factors in the use process, leading to the deviation of the measurement results. Therefore, it is necessary to do a good job of the measurement verification of ultrasonic flaw detector regularly. The metrological verification of ultrasonic flaw detector is studied and discussed from the Angle of ensuring the performance and measurement accuracy of ultrasonic flaw detector and giving full play to the function of the instrument. In the study, the metrological verification process and precautions of ultrasonic flaw detector are defined, and its dynamic range, horizontal linearity, vertical linearity, sensitivity, false positive rate and resolution are verified. The measurement accuracy of ultrasonic flaw detector has been significantly improved before and after comparative verification, and its own performance can be fully brought into play.

This article aims to study the influence of electromagnetic interference on the testing of electric energy meters and corresponding protective measures. By combining experimental and theoretical analysis, this study focuses on the impact of electromagnetic interference on the accuracy of electric energy meter testing, including measurement errors, data instability, and equipment damage. Based on these factors, this article proposes protective measures against electromagnetic interference, including the application of physical shielding technology, reasonable design of filters, and strict attention to the testing of electric energy meters. The results indicate that electromagnetic interference can lead to increased errors in electric energy meter testing, which can cause malfunctions and even incorrect operations. To minimize the impact of electromagnetic interference, this article proposes a series of effective protective measures, including reasonable wiring, installation of filters, and use of shielded cables. These measures have achieved good results in practical applications and significantly improved the accuracy and stability of electric energy meter testing.

Objective To find better conditions and methods to improvethe accuracy and reliability of the measurement by evaluating andanalyzing the total molybdenum uncertainty in soil. Methods The contentof total molybdenum in soil was determined by inductively coupled plasmamass spectrometer with three acid digestion. Results The detection limitof the method was ${0.011}\mathrm{{mg}}/\mathrm{{kg}}$ , thecorrelation coefficient $\mathrm{R}$ of the calibration curve was 0.9999, the recovery was ${97.8}\%$ -105.6%, and the precision of themethod was 2.49%. The extended uncertainty of the method for thedetermination of total molybdenum content in soil was $\left({{0.660}\pm {0.03}}\right)\mathrm{{mg}}/\mathrm{{kg}}\left({\mathrm{K}=2}\right)$ . Conclusion By analyzing the main sources affectingthe uncertainty of measurement, the factors affecting the uncertainty ofthe whole process of determination, such as repeatability, curvefitting, standard solution, sample constant volume, sample weighing,glass measuring tools and sample digestion process were analyzed.Firstly, various conditions during the digestion process, such asdigestion temperature and digestion time, should be strictly controlledto reduce the sample loss. Secondly, microwave digestion, high pressuredigestion and other technologies can be used to optimize thepre-treatment mode to improve the accuracy and reliability of themeasurement results.

Objective To verify the experimental method of erythromycin ointment. Methods Three batch numbers of erythromycin ointment (S1~S3) were selected and divided into three washing methods: test group and positive and negative control group (test article control group and bacterial solution control group). The microbial limit detection method of erythromycin ointment was analyzed by test. Results The recovery ratio of oxygen bacteria, yeast, mold and added bacteria required for different batches of erythromycin ointment in the test is between 0.5 and 2, and the inhibition of microbial strains of erythromycin ointment test can be adopted by membrane filtration method. Therefore, all the methods can effectively eliminate the antibacterial components of erythromycin ointment, and the experimental results can truly reflect the microbial contamination of erythromycin dye ointment. Conclusion The application of centrifugal method in antibacterial removal will not affect the microbial limit test of erythromycin ointment.

By examining the fundamental concepts, classifications of metrological testing, and its roles in ensuring product quality, constructing a foundation for supervisory technology, and facilitating legal enforcement, this paper elucidates how metrological testing technology fosters standardized corporate production, enhances product quality control, and sustains market order. Integrating contemporary technological trends, notably advancements in intelligent inspection technologies, it prospects the future trajectory of metrological testing within the strategy of building a strong quality nation, while proposing strategies to enhance the emphasis on technology, cultivate professional talent, and refine management mechanisms. The research herein underscores the pivotal role of metrological testing technology as a pillar of the quality assurance system, thereby promoting industrial upgrading and securing high-quality economic development.

Objective To understand the monitoring situation of environmental conditions in inspection and testing institutions, analyze existing problems, and provide corresponding countermeasures. Method A self-designed questionnaire was used to conduct a survey and analysis of laboratory environmental monitoring factors in testing institutions. Result 183 inspection and testing institutions were surveyed, and the environmental conditions involved in the laboratories were mainly concentrated in temperature, humidity, microbial pollution, acidity and alkalinity, toxic corrosion, toxic and harmful gases, etc. 96.17% of the laboratories were involved in temperature and humidity, and 83.06% of the laboratories had already carried out environmental condition monitoring. The main environmental conditions monitored were temperature and humidity, accounting for 86.34%, and less than 25% were monitored for current, voltage, light, pressure, noise, vibration, harmful and toxic gases. Only 18.03% of inspection and testing institutions have carried out information monitoring, while other institutions still carry out monitoring and registration through traditional manual recording. 9.84% of inspection and testing institutions have established data models and trend warnings for inspection and testing environmental conditions. Conclusion Inspection and testing institutions involve a wide variety of environmental conditions during the testing process and have complex monitoring requirements. There are still certain shortcomings in the integration of monitoring technology, dynamic monitoring, and monitoring coverage. It is necessary to establish an environmental condition monitoring information platform, establish a hazard trend warning mechanism through data models, and achieve environmental condition monitoring optimization mechanism and intervention management.

Objective Analyze and summarize the factors and precautions that affect the use of N, N-diethylphenylenediamine spectrophotometry for the determination of sulfides in water through experimental analysis. Methods N,N-diethyl-p-phenylenediamine spectrophotometry was used for the determination of sulfide in water. The accuracy and precision of the method were verified by the standard samples with known sulfide content, and all aspects of the experiment were analyzed. Result The N,N-diethyl-p-phenylenediamine spectrophotometry method for the determination of sulfides in water meets the analytical requirements in terms of linearity, precision, and accuracy, making it suitable for the detection of sulfides in clean water. Conclusion When doing the experiment, attention should be paid to sampling, preparation and absorption of standard solutions, and preparation of colorimetric solutions etc. in order to achieve satisfactory results.

Objective To explore the pathogenic factors causing outbreaks of bacterial foodborne diseases. Methods Collecting anal swabs, food retention samples, and food processing tool application samples from patients affected by this epidemic, refer to "Microbiological Testing of Food Hygiene" (GB/T 4789.4-2016、GB/T 4789.5-2012、GB/T 4789.6-2016, GB/T 4789.7-2013, GB/T 4789.10-2016) and "National Clinical Testing Operating Procedures" (Fourth Edition). Results Aeromonas sobria was detected in food samples from little yellow croaker and anal swabs from two patients. Aeromonas hydrophila was detected in a kitchen appliance application and one patient's anal swab. Conclusion This was a rare outbreak of foodborne disease caused by mixed Aeromonas, In the diagnosis and treatment of intestinal infectious diarrhea, in addition to considering common intestinal pathogenic bacteria, rare pathogenic bacteria such as Aeromonas should not be ignored to avoid clinical diagnosis and treatment difficulties.