GB/T 3685 - 2017 Measurement of laboratory-scale combustion characteristics of focused conveyor belts. This standard specifies the test method in detail, covering the construction of the test device, including the construction of the combustion box and the configuration of auxiliary equipment; specifying the sample prepative requirements, such as size, shape and quantity. By setting a simulated combustion environment, recording key data such as flame spread time and combustion degree, the combustion characteristics of the conveyor belt can be accurately evaluated. The standard provides a scientific test basis for ensuring the fire safety of the conveyor belt in actual working conditions, and helps the industry to improve product mass and safety performance.