【摘要】 本文介绍了一种用瞬态热丝法测量气体导热系数的原理,以及根据该原理制成的测量装置和电路框图。用该装置测量时,整个测量时间在100毫秒以内。采用单板机进行测量控制、数据采集与储存。测量结束后,由微型打印机打印出反映热丝温度变化的电压信号。通过理论计算的温升曲线与实测温升曲线的比较,即可求出被测气体的导热系数值。该装置测试的重复精度较高,一般在1%以内。对N₂、Ar、He 在常温常压下的实测结果与国际上公认的推荐值的偏差在5%以内。更多还原

【Abstract】 The transient hot-wire method is used to determine the (?)em-perature variation of a thin metal wire surrounded by the tested gas ver-sus time while a constant current is imposed through the wire.Meanwhile,a series of temperature development profile of the wire can be obtainedbased on Carslaw and Jaeger′s analytical solution for assumed thermalconductivity values of the gas.The corresponding value for the theoreticalcurve which coincides with the experimental curve best is the thermalconductivity of the tested gas.The thermal conducvitities of N2,He and Arat room temperature and atmospheric pressure have measured.The measuringprecision of the device is within 1%,and the relative deviations comparingwith the recommened values are less than ±5%.更多还原