一、前言医疗卫生单位中用于低温贮藏血液和生物制品的冰箱、血库,都设有恒温控制装置。国产的冰箱、血库,多数选用压力式温度继电器作自动控温装置。进口的一些冰箱,有的使用电子线路进行恒温控制,其中简易型的以热敏电阻作感温探头,采用桥式电路,信号经放大后控制开关电路来控温。但以上两类恒温控制装置如用于运血车都有一定的缺点。压力式温度继电器中的机械触头,在汽车的颠簸中,常产生误动作,且这种装置体积大,温度表指针在汽车行驶中不易看清。简易式电子控温线路不能指示温度数值(有的仍采用表针式指示)。为解决 I. Preface The refrigerators and blood banks for low-temperature storage of blood and biological products in medical and health units are equipped with thermostatic control devices. Domestic refrigerators, blood banks, most of the selection of pressure-type temperature relay for automatic temperature control device. Some imported refrigerators, and some use of electronic circuits for thermostatic control, in which the simple type of thermistor for temperature probe, the bridge circuit, the signal amplified by the control switch circuit to control the temperature. However, the above two types of thermostatic control devices, such as those used in blood transfusion vehicles all have certain disadvantages. Pressure mechanical contact in the temperature relay, bumps in the car, often misoperation, and this device is bulky, thermometer pointer in the car is not easy to see. Simple electronic temperature control circuit can not indicate the temperature value (some still use the stylus instructions). To solve