1. Measurement principle: Instruments based on near-infrared spectroscopy absorption principle are more suitable because water molecules have strong absorption characteristics for specific wavelengths of near-infrared light. By detecting the amount of light absorption, the moisture content of tea can be accurately calculated.

2. Measurement accuracy: The moisture content of tea has a significant impact on its quality, so it is necessary to choose a high-precision measuring instrument, generally with a precision of ± 0.1% or higher, to ensure accurate detection of subtle changes in tea moisture in different processing stages.

3. Wavelength range: In the near-infrared region, light with a wavelength in the range of 900-1700nm is more sensitive to tea moisture detection, which can effectively distinguish the absorption signals of moisture in tea from other components and improve measurement accuracy.

4. Stability: The stability of the instrument is crucial, as it relates to the reliability and repeatability of the measurement results. Instruments with good stability can maintain accurate measurements under long-term operation and different environmental conditions, which can be evaluated by examining the product's technical parameters, user evaluations, and the manufacturer's quality assurance.

5. Response speed: In the tea production process, it is necessary to timely understand the moisture content to adjust the process, so a fast response speed is crucial. A good instrument should be able to provide accurate measurement results in a short period of time, so that operators can make timely decisions.

6. Convenient operation: Choosing instruments with simple operation and user-friendly interface can reduce the training cost and work intensity of operators. For example, instruments with high-definition touch screen display, intuitive display of real-time measurement data, and convenient parameter settings and data storage are more popular. In addition, if the instrument has functions such as automatic calibration and automatic fault diagnosis, it can further improve the convenience and reliability of use.

7. Durability: The tea production environment may be complex, with factors such as dust and moisture present. Therefore, the instrument needs to have a sturdy industrial design with functions such as dust and water resistance to adapt to various industrial sites and ensure long-term stable operation.

8. Data processing and transmission function: It is best for the instrument to have data storage function, which can store measurement data for a certain period of time, facilitating subsequent query and analysis. At the same time, it has data transmission interfaces such as RS232, USB, etc., which can transfer data to computers or other devices for further processing and management, helping to achieve the informatization and intelligence of the production process.

9. After sales service: High quality after-sales service is an important consideration when choosing instruments. Manufacturers should be able to provide timely technical support, maintenance services, and sufficient supply of accessories to ensure that instruments can resume normal operation as soon as possible in the event of a malfunction, reducing the impact on production.

10. Cost effectiveness: Taking into account factors such as instrument price, operating costs, and maintenance costs while meeting testing requirements, select products with high cost-effectiveness to achieve greater economic benefits.