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

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..