GB/T 3 2710.4 - 2016 "Safety Specifications for Environmental Test Instruments and Equipment, Part 4: High-temperature thermostatic circulation devices" specifies the safety requirements for high-temperature thermostatic circulation devices. The standard covers the safety content of electric shock, electric burns, mechanical hazards, flame spread, excessive temperature, fluid pressure, radiation effects (including laser, sound pressure and ultrasonic pressure), gas release, explosion, implosion, and biological and chemical hazards, but does not cover the function of equipment, performance, Encasement effectiveness, electromagnetic compatibility, explosion protection measures and protection of maintenance personnel. The scope of application includes high-temperature thermostatic circulation devices in laboratories and industrial sites, especially immersion devices with external circulation function. The standard requirements also meet the relevant standards of industrial automation products. Normative reference documents include GB 4208-2008 "Protection level (IP code) of enclosure" and GB 4706 series standards.