基于铂电阻PT100的隔离测温仪设计

A design of isolated thermoscope based on platinum resistance

介绍了一种基于铂电阻PT100的隔离测温仪的实现方案。采用三线制恒压源驱动铂电阻PT100,使不同的电阻阻值在运放的两个输入端产生不同电压差,经运放放大后输入线性光耦,隔离后的信号经AD转换为数字信号,送给CPU进行处理。本系统精度高、性能稳定,适合工业领域对精度要求高、测试条件恶劣的温度测量。

A new implemented scheme on PT100 isolated thermoscope is introduced. Platinum resistance PT100 is drived by constant voltage source of three wire system,different resistance value produce different voltage on two input terminal of operational amplifier, the out of value is inputed into linear optocoupler,then is converted into digital signal,the digital signal is processed by CPU. The design, characteristic of its high temperature precision and performance stability, is fit for situations requiring high temperature preci- sion and extremely hard conditions.