Training Case of GNST-900S Multi parameter Water Quality Detector at Yangtze River Delta Research Institute, University of Electronic Science and Technology of Huzhou, Zhejiang Province

1、 Training background and objectives

（1） Background Overview

（2） Core objective

1. Theoretical level: Enable trainees to understand the detection principle, core technical indicators, and national standard basis of GNST-900S instrument, and clarify the applicable scenarios for different water quality indicators testing.

2. Practical level: Ensure that trainees are proficient in the entire process of instrument startup self check, parameter calibration, sample preparation and testing, data storage and export, and can independently complete the testing of typical water quality indicators.

3. Guarantee level: Master the common troubleshooting methods and daily maintenance points of instruments, extend the service life of instruments, and ensure the long-term stability and reliability of detection data.

4. Application level: To achieve deep integration of theory and scientific research practice, enhance the ability of trainees to use instruments to solve practical scientific research problems, and lay the foundation for the smooth progress of related environmental monitoring scientific research projects.

2、 Training preparation

（1） Organizational Structure

（2） Preliminary preparation

1. Site and equipment preparation: The standardization laboratory of the research institute is selected as the training site, and the operation table is organized in advance to ensure good ventilation and that the temperature and humidity meet the requirements for instrument operation (temperature 5-40 ℃, relative humidity ≤ 85% RH). Place the GNST-900S host, multifunctional intelligent digestion instrument, supporting testing tubes, prefabricated reagents and other equipment and materials in place according to the operating line, complete the power connection and power on self-test, and ensure that all equipment is in normal working condition; Prepare calibration solution, simulated water sample, deionized water, lens cleaning paper and other practical consumables at the same time.

2. Preparation of materials and tools: Each participant shall be equipped with one set of "GNST-900S Multi parameter Water Quality Tester Manual", training materials (including theoretical knowledge points, operation process diagrams, and common problem manuals), and electrical insulation tools, equipment debugging tools, and materials such as "Training Sign in Form" and "Practical Assessment Scoring Form".

3. Customized plan: The lecturer communicates with the research leader of the research institute in advance, and adjusts the training content accordingly based on the water quality testing needs of the institute's key research projects. The focus is on strengthening the operation training of core indicators such as COD, ammonia nitrogen, total phosphorus, and total nitrogen, ensuring that the training content is in line with the actual research situation.

3、 Training Implementation Process

（1） Theoretical explanation session (9:00-10:30)

1. Core principle of the instrument: Detailed explanation of the LED cold light source optical structure, data homogenization calculation algorithm, and other core technologies of the GNST-900S instrument. Explain the principles of different detection items, such as the potassium dichromate method for COD, the Nessler's reagent method for ammonia nitrogen, and the ammonium molybdate method for total phosphorus. Compare the technical requirements for each indicator detection with the national standard.

2. Technical specifications and functions: Introduce key technical parameters such as the detection range, detection limit, relative error, and repeatability of the instrument, demonstrate the operation logic of the 8-inch IPS high-definition color touch screen, and explain the application scenarios of core functions such as data storage (supporting 100000 data storage), automatic printing, and batch testing.

3. Safety and Standards: Emphasize safety precautions for experimental operations, including reagent usage standards, power connection safety, and protection points for high-temperature digestion processes; Clarify the standard process for water sample collection, preservation, and pretreatment, and explain the impact of details such as cleaning the sampling container and collecting water sample overflow on the test results.

4. Maintenance and troubleshooting basics: Briefly explain the core points of daily instrument maintenance, such as probe cleaning, reagent storage, battery maintenance, etc; Briefly introduce the preliminary judgment methods for common faults such as unresponsive startup and data drift.

（2） Practical demonstration session (10:40-11:40)

1. Instrument initialization: Demonstrate the power on self-test process and explain how to determine the operating status of the instrument hardware (display screen, buttons, light source) and software system; Introduce the parameter adjustment methods for the system settings interface, such as date and time settings, measurement unit switching, etc.

2. Calibration operation: Taking COD (low range) and ammonia nitrogen detection as examples, demonstrate the two-point calibration process - after cleaning the electrode with deionized water, immerse it in standard buffer solution/calibration solution in sequence, wait for the reading to stabilize, complete the calibration and save the parameters, emphasizing details such as shaking the calibration solution before use and avoiding cross contamination.

3. Sample testing: demonstrate the standard addition of pre made reagents, the precise extraction and digestion process of water samples, and explain the one click digestion operation of the multifunctional intelligent digestion instrument; Put the processed sample into the instrument for testing, demonstrate the method of data stability judgment and result recording.

4. Data export: Demonstrate the operation steps of exporting detection data to a computer through a USB interface, and explain the interpretation method and archiving requirements of data files.

5. Closing operation: Explain the cleaning process of the instrument after the detection is completed (rinse the probe and detection channel with deionized water), the correct storage method of the probe, and the key points of equipment organization.

（3） Group practice session (13:30-16:00)

1. Basic operation exercise: Each group completes the instrument power on self-test, system parameter setting, and calibration of core indicators (COD, ammonia nitrogen) in sequence. The instructor provides tour guidance to correct any non-standard operations, such as electrode cleaning or insufficient calibration waiting time.

2. Sample testing exercise: Using pre prepared simulated water samples (containing target pollutants with different concentration gradients), complete the entire process from water sample pretreatment, reagent addition, digestion to detection, record test data, compare test results between different groups, and analyze the reasons for differences.

3. Fault simulation and troubleshooting: The instructor sets common fault scenarios, such as "instrument unresponsive", "large data fluctuations", "data export failure", etc., and divides the trainees into groups to troubleshoot and solve them, strengthening their grasp of fault handling methods.

4. Q&A: Participants may ask the instructor questions about potential issues they may encounter in scientific research practice, such as "Methods for removing interfering substances from complex water samples" and "Calibration points for instruments that have not been used for a long time". The instructor will answer each question and provide extended explanations.

（4） Assessment and Summary Session (16:10-17:00)

1. Practical assessment: Randomly select one core testing indicator (COD/ammonia nitrogen/total phosphorus/total nitrogen) in groups, and complete the entire process from calibration to testing and data export within the specified time. The instructor will score based on the dimensions of operational standardization, data accuracy, and operational efficiency, with a pass rate of 100%.

2. Training Summary: The instructor reviewed the core knowledge points and operational essentials of this training, sorted out the common problems that the trainees encountered in practical operation, and provided improvement suggestions; The research director of the research institute summarized the training results, emphasized the importance of standardized use of instruments for scientific research work, and established a long-term technical exchange mechanism to clarify the feedback and solution channels for problems in the subsequent equipment use process.

3. Feedback collection: Distribute training feedback questionnaires to collect opinions and suggestions from trainees on training content, lecturer level, practical arrangements, and other aspects, providing reference for optimizing training work in the future.

4、 Training effectiveness

1. Skill Enhancement: All participants have proficiently mastered the theoretical knowledge and practical skills of GNST-900S instrument, and are able to independently complete the detection of core water quality indicators. The operational standardization and data accuracy meet the expected requirements, solving the problems of "knowing how to use but not precise" and "large data fluctuations" previously.

2. Research support: After training, the instrument was quickly put into research projects such as "Huzhou River Water Quality Monitoring and Ecological Restoration" at the research institute. The detection efficiency increased by more than 40% compared to before, and the data stability was significantly enhanced, providing accurate and reliable experimental data support for project research.

3. Management standards: Established a registration system for instrument use, regular calibration and maintenance system, and clarified equipment management responsibilities for trainees, effectively reducing instrument failure rates and extending equipment service life.

4. Mechanism establishment: Through this training, the technical cooperation between the research institute and instrument suppliers has been deepened, and a long-term technical exchange channel has been established, laying a good foundation for solving complex detection problems and upgrading detection technology in the future.

5、 Experience Summary and Prospect

（1） Experience summary

1. Precise customization is key: This training closely integrates with the actual research needs of the research institute, focuses on core testing indicators, and designs targeted training content to avoid the "general but not precise" nature of generic training and improve the effectiveness of the training.

2. Practical orientation is the core: adopting a practical teaching mode of "demonstration+practice+fault simulation", participants can master skills in practice, and correct erroneous operations in a timely manner through one-on-one guidance, effectively improving learning efficiency.

3. Multi party collaboration is a guarantee: the efficient collaboration between the research institute and suppliers ensures sufficient preparation of training venues, equipment, consumables, and other resources. The professional lectures and subsequent technical support of the instructors provide strong guarantees for the consolidation of training effectiveness.

（2） Future prospects