测量引线热电势对热电阻测温系统测温结果的影响分析CSCD

热电阻测温系统广泛采用单向电流恒定激励,通过测量热电阻两端电势差获得热电阻阻值的方法进行温度测量。而此类测温系统受到测量引线热电势的影响,所测得热电阻的阻值往往与实际阻值存在一定的偏差,从而影响测温结果。对电路中热电势对热电阻测温结果产生影响的机理进行了分析,并通过实验验证了分析结果,提出了减小或消除热电势差对测温结果影响的建议。

Analysis of Effect by Thermoelectric Potential in RTD Temperature Measurement System

The fixed constant excitation current direction is widely used in RTD temperature measurement system. Usually the temperature is measured by measuring the resistance of RTD which is gauged from potential difference. The system is always affected by the thermoelectric potential. The measured resistance of RTD is different from the actual data, which will affect the temperature measurement results. The mechanism of thermoelectric potential which impacts on the results of the temperature measurement in the circuit is analyzed and the analytical results are verified by experiment. The recommendation and guidance of reducing or eliminating the impact of the thermoelectric potential difference on the results of temperature measurement are proposed.