High temperature steel shield is when the camera is used in more than 40 DEG C, by natural convection and radiation heat transfer can not reach the normal operating temperature of the environment, to protect the camera lens, the normal work of the steel protective cover. For the high temperature environment, plate steel shield should adopt special cooling means. Common cooling system air cooling system, cooling system, and the vortex refrigeration, freon, ammonia refrigeration etc..

Air cooling system is still used for air flow cooling principle, using forced ventilation ways of coolant （ air purification ） into the steel protective cover or shield plate layer, the shield plate in heat from, for cooling. Forced ventilation cooling system having a direct cooling and indirect cooling two.

The environment temperature is greater than 80 degrees C （ such as heating furnace, steel furnace etc.） by forced air cooling has been unable to control the temperature rise, the forced cooling system. Water thermal conductivity and specific heat than air to be big, so compared with air cooling, greatly reduces the heat exchange segment about thermal resistance, improve the efficiency of heat transfer.