薄膜热电阻热流传感器的对比标定结果及分析

Calibration results and analysis of thin-film gauges calibrated with the transfer method

常用于薄膜热电阻热流传感器(简称薄膜热流计)的两步法存在标定步骤多、误差源多等问题。在解决吸收薄膜必要性、标定时限和标定热流范围等问题的基础上,实现了薄膜热流计的对比标定。在对比标定薄膜热流计时,基体材料的热物性参数乘积及热电阻的电阻–温度系数被处理为简单的传感器灵敏度系数,使得标定实验仅需重复简单的步骤,有效减少了误差源;针对通过对比标定获得的多支薄膜热流计灵敏度系数差异大的问题,在分析其测温原理的基础上,通过去除热电阻的电阻–温度系数,得到同一批次生产的多支薄膜热流计较为一致的修正灵敏度系数。薄膜热流计对比标定结果的扩展不确定度不超过6.5%,明显优于两步法标定结果的扩展不确定度(约10.7%),提升了薄膜热流计测热结果的可信度。

Considering the fact that there are more error sources in the measured heat flux with thin-film gauges when the two-stage approach is applied to determine the thermal product and resistance–temperature factor,the transfer method is applied to directly calibrate thin-film gauges,in which the thermal product and resistance-temperature factor are treated as the sensitivity coefficients.To get the consistent calibration results of different thin-film gauges fabricated in a batch,the sensitivity coefficients are divided by the resistance–temperature factors of the thin-film gauges,and then the correction sensitivity coefficients are consistent.With the transfer calibration technique,the calibration results of thin-film gauges show a good linearity with a relative expanded uncertainty below 6.5%,which is lower than that reported in other researches,in which the two-stage approach is used to calibrate thin-film gauges.