1   The manufacturing and production of environmental testing equipment has been developing continuously for decades, and its basic technologies (such as refrigeration, dehumidification, heating) have matured. With the progress and development of industrial technology, many new application technologies have been introduced into environmental test equipment, such as computer technology, fuzzy control theory and so on. Each manufacturer has accumulated decades of experience in manufacturing the equipment produced by its working principle, applied technology, and even the structure, materials and so on have many similarities. However, due to the restriction of the production mode of "multi-non-standard, multi-variety, small-batch" environmental testing equipment, the reliability of products has always been a problem that troubles domestic and foreign manufacturers. The key lies in the manufacturer must be fine management, complete process, complete testing methods, serious responsibility for quality. At the same time, environmental testing equipment is a durable goods, some problems and design defects need many years to expose, through statistical analysis to find the problem. A mature and highly reliable product often needs to be improved and perfected for many years. Therefore, the manufacturer of environmental testing equipment has a certain production scale and production history, which is one of the necessary conditions for high reliability of products.

2   Quality control of production process. The quality control of the domestic production process has been greatly improved. The quality control of the production process is related to the management level and production mode of the manufacturer. The demonstration of ISO is a sign that the quality control of the production process is standardized. In addition, the manufacturer of temperature and humidity environmental test equipment at home and abroad has accumulated rich experience in the production of climate and environment test, as to how to choose. Manufacturers, there are still some factors worthy of consideration and consideration.

（1）Cost performance

On the basis of fully verifying the technical parameters and reliability of environmental testing equipment, cost performance ratio is an important factor to be considered. All imports of environmental testing equipment are sold through agents in China. The price factor not only depends on the cost and profit of the manufacturer, but also includes many intermediate costs and commissions. Under the same manufacturing cost, reducing the intermediate cost is an important factor to reduce the order price. The manufacturing cost of the products with the same country's technical indicators is roughly the same, and the products produced by different countries will not be too different even if there is a big difference.

（2）The degree and ability to meet users' needs.

When users order equipment, it is mainly based on the needs of the test workpiece to choose, many are non-standard requirements, so whether the manufacturer can meet their test requirements and the degree of satisfaction, is also the embodiment of the manufacturer's ability, will also be an important factor of concern to users.

（3）After sales service and equipment fault handling capacity.

 Some faults will inevitably occur during the long-term use of the equipment. Whether the user can enjoy timely maintenance service or can quickly determine the fault treatment method according to the fault diagnosis ability of the equipment itself, so that the equipment can recover its performance as soon as possible and put into use again. In this regard, manufacturers at home and abroad have made or are making active efforts, such as the establishment of a rapid response maintenance team, such as the addition of computer control systems in the diagnosis and early warning system software, users can provide information from the computer, as soon as possible to deal with the fault.