介绍了用AD595作信号调理,PIC16F877芯片为控制核心制作的恒温仪的设计｡仪器采用加热丝升温,热电偶为传感元件｡在使用热电偶时,往往由于环境和现场条件等原因,冷端温度不能维持在0 ℃(To≠0),使热电偶输出的电势值产生误差｡AD595芯片是针对上述问题设计的专用芯片,内部具有放大､冷端补偿､冰点基准､温差电偶故障报警等电路｡在系统中做信号调理单元｡软件主要是对信号检测处理后,给出控制信号,稳定仪器温度｡ Constant Temperature Controllable Instrument Based on AD595 ZHAN Li-guo,ZHENG Xiao-lin,CHEN Feng,HOU Wen-sheng,YANG Jun,LIU Li,CAO Yi,YANG Jing (Chongqing University, Chongqing 400044, China) Abstract:The fabrication of temperature controllable instrument based on PIC16F877 and AD595 was introduced. Calefaction tread is for hear up, thermocouple is the temperature sensor.However, when thermolouple being put into use, the external conditions always make the cold end temperature can not be maintain at 0 ℃(To≠0), which make the output is error. AD595 chip is aimed at all above problem. In this system, it is to be used to regulate the temperature signal. The software's main work is to detect and dispose the temperature signal, then give control signal to stability the instrument temperature. Key words:signal regulation;Control onit;thermocouple