地震水温观测仪器热迟滞性、漏热效应和仪器漂移实验研究

Experimental Study on Thermal Hysteresis,Heat Leakage Effect,and Instrument Drift of Seismic Water Temperature Observation Instruments

参照IEC 60751和ASTM E644-11国际标准,在0~100℃、0~70℃和0~50℃温度范围对石英晶体型、铂电阻型和热敏电阻型地震水温观测仪器(简称测温仪)开展热迟滞性研究,明确局浸法校准漏热效应,分析两者对测量不确定度的贡献,并查明仪器漂移特征。结果表明,测温仪热迟滞性随着测量点温度降低而减小,最大值为0.025 5℃(铂电阻型,50℃测量点);在相同测量点,石英晶体型测温仪的热迟滞性小于铂电阻型和热敏电阻型。采用局浸法校准时,感温元件的浸没深度应不小于30 cm,漏热效应最大值约为0.01℃(100℃测量点)。热迟滞分量对铂电阻型测温仪测量不确定度的贡献最大(约60.7%),石英晶体型测温仪则表现出最佳的测量准确度。不同类型传感器的仪器漂移测量结果接近,极差仅为0.000 3℃/24 h。未来可通过替换感温元件、优化设计、提升工艺和使用大深度恒温槽、保温装置、修正公式等方法提高仪器稳定性,减小校准漏热效应。

According to IEC 60751 and ASTM E644-11 international standards,we study the thermal hysteresis of quartz crystal type,platinum resistance type and thermistor type seismic water temperature observation instruments in the temperature ranges of 0℃to 100℃,0℃to 70℃and 0℃to 50℃,and define the heat leakage effect of local immersion calibration.Further,we analyze the contribution of both to measurement uncertainty,and identify the instrument drift characteristics.The results show that the thermal hysteresis of thermometer reduces with the decrease of measuring point temperature,and the maximum value is 0.0255℃(platinum resistance type,50℃measuring point).At the same temperature point,the thermal hysteresis of quartz crystal type thermometer is less than that of platinum resistance and thermistor types.When the local immersion method is used for calibration,the immersion depth of temperature sensing element should not be less than 30 cm,and the maximum heat leakage effect is about 0.01℃(100℃measuring point).The thermal hysteresis component contributes the most to measurement uncertainty of platinum resistance thermometer(about 60.7%),and quartz crystal thermometer shows the best measurement accuracy.The measurement results of instrument drift for different sensor types are close,with a range of only 0.0003℃/24 h.In the future,the instrument stability can be improved,and the heat leakage effect can be reduced,by replacing the temperature sensing element,optimizing the design,upgrading the process,using a large depth constant temperature bath,heat preservation device and modifying formula.