ABSTARCT Study of two unused transformer oils was carried out by determining the thermo-acoustical parameters employing ultrasonic interferometer. The two transformer oils studied were of the year 1997 and 2017 make. The density measurement was carried out on the two oil samples at varied temperatures. The ultrasonic velocity for two different transformer oil samples in the temperature range of ambient to 343 K was measured for multiple frequencies. The measured ultrasonic velocity was used to calculate the thermo-acoustic parameters like adiabatic compressibility (β), intermolecular free length (Lf) and acoustic impedance (Z). The thermal conductivity variation with temperature of the oils was determined. The determined and observed parameters of the oil samples are thoroughly deliberated in this paper.

中文翻译：

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利用超声波技术研究变压器油的热声学

ABSTARCT 通过使用超声波干涉仪确定热声参数，对两种未使用的变压器油进行了研究。研究的两种变压器油是 1997 年和 2017 年制造的。在不同温度下对两种油样进行密度测量。在环境温度至 343 K 的温度范围内，针对多个频率测量了两种不同变压器油样品的超声波速度。测量的超声速度用于计算热声参数，如绝热压缩率 (β)、分子间自由长度 (Lf) 和声阻抗 (Z)。确定了热导率随油温度的变化。本文详细讨论了油样的测定和观察参数。