| 摘要 |
PURPOSE:To enable the maintaining of temperature of an infrared detector at a fixed value regardless of change in environment temperature, by controlling a cooling capacity of a cooling machine by detecting signal of a cooling temperature detection sensor and an environment temperature detection sensor of the infrared detection element. CONSTITUTION:Revolutions of a compressor is heightened by a feed back control system comprising a cooling temperature detection sensor 13 of an infrared detector and a second control circuit 15 of a refrigerating machine and a feed forward control system comprising an environment temperature detection sensor 12 and a first control circuit 14 of the refrigerating machine to increase a cooling capacity of the refrigerating machine. With the increase in the cooling capacity, a cooling temperature of the infrared detection element is lowered to keep the cooling temperature constant. Conversely, the cooling capacity of the refrigerating machine is reduced by lowering the revolutions of the compressor to keep the cooling temperature constant with a rise in the cooling temperature of the infrared detector. Thus, the cooling temperature of the infrared detector can be kept constant regardless of change in environment temperature. |
