Markers of cellulose insulation ageing: Calculation of total methanol quantity in the internal insulation of power transformersL.A. Darian, R.M. Obraztsov, A.V. Maksimchenko, D.E. Verakso, V.P. Polishchuk and V.A. LogunovE3S Web Conf., 584 (2024) 01011DOI: https://doi.org/10.1051/e3sconf/202458401011