导热误差对温度测量的影响

Conductive error influence on temperature measurement

为了研究直型传感器的导热误差,设计了可同时测量气流温度、支座上部温度和支座下部温度3个测点的传感器,其中测点1和3可根据研究的需要上下移动,并建立了理论模型,推导了导热误差的计算公式.为了避免辐射误差对导热误差的影响,采取根部加热的办法,研究了马赫数、支座温度、长径比对导热误差的影响,得到了可供参考的数据,并将导热误差的计算公式应用到气流流速较低时(Ma=0.1)高温水冷耙某点的导热误差的计算中,计算结果与测量结果误差小于10%.考虑导热误差对测温的影响时,应综合长径比和支座温度两方面的因素,将长径比是否大于10作为衡量是否考虑导热误差的唯一标准是不全面的.

To study the conductive error of straight sensor, a special sensor was designed, which can measure 3 points＇ temperature, air flow, downside and upside of the bracket. The first and the third point were movable to meet the need of study. The theory model was set up and conductive correct coefficient formula was deducted. To avoid the influence of radiation error, a method of boot-heating was adopted to study the influence of Ma, bottom temperature and long-diameter ratio to conductive error, and useful datum were received. Conductive correct coefficient formula was applied to calculate conductive error of high-temperature-watercooled harrow when the air flow velocity was low （ Ma = 0.1 ）. The relative error was little than 10%. It pointed out that when considering the conductive error on temperature measurement, it is not comprehensive that whether long-diameter ratio is larger than 10 or not, bottom temperature is also an important thing.