Abstract
Various molecular weight measuring methods of insulating oil have been proposed from long ago. At present, method of Hirschler is well known. This method is obtained from the temperature dependence of viscosity, and is used frequently to measure ring analysis of insulating oil or lubricating oil. However, this method is hard to obtain the molecular weight.
So, here is studied about easy measuring method of the molecular weight. As a result, following equation was obtained from compensation low and the temperature dependence of viscosity, M=0.053ln(η/0.0036)/(1/RT-0.001), where M is the molecular weight (g/mol), η is the viscosity (Poise), R is 1.987cal/mol•deg, T is the temperature (K).
By modifing the equation, the molecular weight calculating equation was obtained from the density at 15°C, d15(g/cm3) and the kinematic viscosity at 40°C, ν40(cSt) in Japanese Industrial
Standerd tests of insulating oils as follows, M=87.2ln(2.73d15ν40).
In this study, further, temperature dependence equation of viscosity was deduced by using compensation low.
