新型多路Pt100温控变送器

Innovative Multi-channel Pt100 RTD Transducer

Pt100热电阻是一种应用广泛的温度测量传感器,传统的巡检或一对一检测方式其精度易受到Pt100连接电缆阻值的影响,时效性较低,成本也较高。文中利用具备高一致性、低导通电阻(小于0.45Ω)、低漏电(小于50 n A)的新型模拟开关TS3A44159,提出一种新型多路Pt100温控变送器,通过切换多个四通道模拟开关实现一片传感器信号环流变送器AD693采集多个三线制Pt100热电阻的多通道精准测控模式,绝对误差小于0.3℃。实际工程应用表明,该变送器温度测量精度满足工业需求,数字RS485输出,增大了通信距离,实现了网络化分布式多设备、多测点的温度监测。

Pt100 RTD is a kind of widely used temperature sensor measurement. The accuracy of traditional measurement mode can be affected by the connecting cable resistance. The timeliness of the traditional measurement mode is low, but the cost is high. An innovative multi-channel Pt100 RTD transducer based on analog switch TS3A44159 with high consistency, low on -state resistance （less than 0. 451Ω） and low leakage （less than 50nA） was presented in this paper. Each three-wire PtlO0 RTD needed a four-channel analog switch in the multi-channel system, while only one AD693 was used to convert measurement result to temper- ature in a cyclic detection. The absolute error was less than 0.3 ℃. Practical application shows that the accuracy of the temperature measurement transducer meets the industrial demand and the digital RS485 output increases the communication distance, thus form- ing the temperature monitoring system with distributed network of multi-points and multiple equipments.