3ω线法测量液体热参数影响因素分析

ANALYSIS OF INFLUENCE FACTORS IN MEASUREMENT OF LIQUID THERMAL PROPERTY WITH 3ω-LINE TECHNIQUE

首先给出基于谐波探测技术测量液体导热系数和热扩散系数的3ω线法的基本原理。采用实验和理论分析相结合的方法,分析了加热丝结构参数和自身热参数对温度波动和测量结果的影响。给出了加热丝直径和长度的合理范围。液体导热系数比较小时可以利用三次谐波的实部和虚部的交点测量液体的比热容。

The principle of 3ω-line technique for determination of thermal conductivity and thermal diffusivity of liquid is given based on harmonic detection technique. Both the experimental and theoretical analysis is made of the effect of heating wire geometry and its thermal parameters on the temperature oscillation and measured results. The range of diameter and length for the heating wire is determined. The point of the real and imaginary parts of the third harmonics can be used to determine the specific heat of liquid when the thermal conductivity is relatively small.