【摘要】 采用传感器复用技术对超高温试样的温度及热扩散率进行精确测量。根据比色温度计测量原理,推导了计算被测物体表面温度的通用计算公式,讨论了将高温非金属材料视为灰体的可行性,探讨了采用两个探测器分别对两个温度区间的温差信号进行测量的方法,设计了利用传感器输出信号同时对温度和温差进行测量的高精密放大电路,并介绍了相应装置的研制情况。标定结果表明,这套高温计的测量范围为1073~3773 K,测试误差小于1%。对SRM 8424标准试样在1073~3273 K温度范围内的热扩散率进行了测量,与NIST的测量数据(1073~2673 K)相比,最大测试误差为4.34%。本研究结果实现了对超高温材料温度和热扩散率的同时测量,为该领域测量装置的研制提供了一个新思路。更多还原

【Abstract】 In order to measure the temperature and the thermal diffusivity of ultra-high temperature material precisely and simultaneously,the combination of multi-wavelength technique and laser pulse method was studied.Based on the principles of thermal radiation and temperature measurement with color pyrometer,a general formula for computing the true surface temperature of objects was developed.The feasibility of using nonmetal material as grey body was discussed mainly,the method of measuring temperature difference of corresponding temperature scale using two detectors was analyzed,and the measurement methods for the temperature difference on different temperature ranges were analyzed respectively using two detectors.Then the high-precision amplifier was investigated for measuring temperature and thermal diffusivity simultaneously with the color pyrometer.Finally,the measuring apparatus was introduced in detail.The results of temperature calibration show that the pyrometer’ measuring temperature range is from 1073 K to 3773 K and its measuring error is less than 1%.To demonstrate the performance of the apparatus,thermal diffusivities of a standard specimen-SRM 8424-in 1073~3273 K are measured,and the largest measuring error compared with NIST is 4.34% in 1073~2673 K.It is shown that the proposed method provides a new idea for measuring temperature and thermal diffusivity of ultrahigh temperature materials simultaneously.更多还原