多路高精度热电偶采集板研制

Development of multi-channel high-accuracy thermocouple acquisition-board

为了满足工业应用现场多点测温的需求,研制了16路热电偶高精度数据采集板。选取ADI公司的高性能芯片ADμC834作为主芯片,利用其片上24位∑-Δ型A/D、外部高精度参考电压模块,结合信号调理电路和下位机软件的设计,实现了高精度数据采集。采用多路转换芯片,可实现了16路采集通道间的切换。采用热电阻PT100传感器采集热电偶冷端温度实现冷端补偿。实验结果表明,该采集板具有多通道、精度高、成本低、测温范围宽、操作简单等优点。

In order to meet the requirement that industrial field need to measure lots of temperatures,16-channels high-accuracy thermocouple acquisition-board was developed,the ADμC834 chip made by ADI Corporation was chased as main chip.By using the on-chip 24bit ∑-Δ type A/D,external high-accuracy reference-voltage module,combined with the rational design of signal conditioning circuit and MCU program,the high-accuracy acquisition was realized.Multi-channel conversion chip could switch 16 channels.To realize cold junction compensation,thermal resistance PT100 was used to acquire the cold-side temperature.The experiments show that the acquisition-board has the merits of multi-channel switch,high-accuracy,low cost,wide metrical range of temperature,simple operation,etc..