液氮致冷控制系统设计

超低温液氮致冷控制系统主要包括温度采集控制和密闭容器中液氮高度测量两个部分.温度采集控制部分主要利用单片机对温度传感器不断地进行巡回检测,采集温度传感器检测到的实际温度与设定的阈值进行比较,从而决定是否需要排放液氮,降低冷藏室的温度,达到所需要求.液氮液面高度测量控制部分是利用电阻/电压转换器、A/D转换器,以数字形式显示出液面高度来实现的.当检测到液氮液面高度小于1 cm时,发出自动报警信号.

Ultraslow temperature liquid Nitrogen controlling system

This article mainly introduces a kind of ultralow temperature liquid nitrogen system for detection and control of liguid nitrogen temperature and liguid nitrogen surface height in a closed container. By dint of SCM, temperature detection controlling can itineranly detect temperature transducer constantly, and gather actual detecting figures from that temperature transducer. Comparing the actual temperature with the setting threshold,one can decide whether the liquid nitrogen should be let off for controlling temparature of the system to be safe in operation. The liquid using R/V and A/D converting. nitrogen surface level was measured and displayed by