用于低温试验的多通道高精度铂电阻测温电路

在低温推进剂蒸发量控制等低温试验中,高精度的温度测点数量多,并且要求必要时屏蔽失效的测点,导致调理电路成本较高。为解决上述问题,设计了一种适用于低温试验多通道温度测量的铂电阻测温电路。设计了恒流源电路、放大滤波电路。利用ATMega328P和串口屏开发了通道控制和人机交互界面。用于测温的多个铂电阻与已知参考电阻以同一个恒流源串联供电,通过比例式测量消除了恒流源性能对测量精度的影响。误差分析和测试校准证明其电阻测量精度达到0.05%,可广泛应用于实验室和试验现场的低温测量系统中。

Multi-channel high precision platinum resistance temperature measuring circuit for cryogenic test

In cryogenic test like cryogenic propellant boil-off control test,a large number of high-precision temperature measuring points are required.As such,issues of conditioning-circuit deployment and its cost,for the purpose of multi-channel measuring and disabling ineffective points,are most pronounced.For this reason,a multi-channel platinum resistance temperature measuring circuit for cryogenic test was realized here.A current source,an amplifying and filtering circuit and an interacting channel control system based on ATMega328P and serial screen were designed.Multiple platinum resistors for measurement were connected in series with a known reference resistor.All resistors were driven by a current source.The influence of current source performance on accuracy was eliminated by comparative measurement.Error analysis and experiments proved that the resistance measuring accuracy is 0.05%.The system can be widely used in cryogenic measurement systems in laboratory and testing field.