Appendix: Reference Guide for Selection of Test Chamber Suppliers
It is easy to identify some factories that are too small in the same industry through the photos of factory buildings and processing equipment provided by manufacturers. Small factories in the same industry generally do not have the necessary processing equipment. It is unrealistic to guarantee quality and after-sales service for these small companies, so it is not recommended to consider purchasing them.
Through on-site inspections of supplier manufacturers, the supplier's quality assurance capabilities can also be effectively identified.
The rule of the test chamber industry is: the lower the price, the lower the sales volume.
The reason is: differences in product reliability and the number of repeat customers.
Appendix: Characteristics of the Test Chamber Industry and Basic Product Conditions
The environmental testing equipment industry has the characteristics of small batches, multiple varieties, and non-standard products. Quality control is difficult, and the product reliability of the test chamber industry is low.
Most manufacturers in the test chamber industry have only 10 or 20 employees (they will claim to have hundreds of employees) and rent a few hundred square meters of factory space . These manufacturers are too small and do not have any processing equipment (due to too many varieties and small batches, the quality of outsourced processing of structural parts cannot be controlled), and lack effective after-sales service guarantees. Since there are millions of customers who need test chambers in China, more than 99% of them are "one-time consumers", that is, the re-purchase cycle is very long, or they will not re-purchase. Therefore, manufacturers with no quality and after-sales guarantee can also have a large market space by constantly developing new customers. The sales model of these manufacturers is "comparing configurations and prices", and most of them use low-temperature accessories and electrical accessories that are counterfeit imported brand products.
In fact, in addition to the genuine parts that must be configured, the reliability of the products in the test chamber industry mainly depends on the system integration. For example, the types of refrigeration system failures include "blockage, leakage, and burning". "Blockage" is divided into ice blockage (improper system water treatment), oil blockage (improper oil separation and system layout design), and slag blockage (improper process treatment). "Leakage" is divided into welding leakage, riveting leakage, and leakage of various devices. "Burn" compressors have many reasons such as slag destroying the insulation layer, too high return air temperature, improper system load, etc. In addition, common failure types include many reasons such as damage to the compressor connecting rod and valve plate.
Therefore, even if equipped with genuine parts, the test chamber has hundreds of common failure types. To avoid these failures as much as possible, scientific design specifications, process specifications, technical specifications, and manufacturing specifications are needed. It is not simply "comparing configurations" to ensure good product quality. Most of the manufacturers in the test chamber industry are small in scale, with poor quality management and guarantee capabilities. There are many varieties and specifications of products, and the probability of product failure is high. Moreover, most of the failures are systematic and difficult to solve through after-sales maintenance.
Therefore, it is recommended to arrange video audits of the supplier's facilities, with each audit lasting ten minutes. The vast majority of factories in the test chamber industry are small, with only a few or a dozen employees, renting factory space and outsourcing sheet metal equipment. Their fixed assets are less than 300,000 RMB (excluding cars), making their promotional materials appear very difficult to verify. However, this is not apparent without video audits. These audits include reviewing the supplier's processing equipment, production site, management practices, factory gates, factory buildings, and property ownership certificates and numbers. This method is efficient and low-cost, significantly mitigating procurement risks.