| 摘要 |
PURPOSE:To estimate the life of insulating paper by detecting long-term deterioration at relatively low temp., by performing judgement by using at least one of methyl formate and methyl acetate being a methyl ester type substance as an index substance. CONSTITUTION:The judgment of insulating paper is performed by using at least one of methyl formate and methyl acetate being methyl ester type substances which are the deterioration products inherent to the insulating paper and further are substances formed in long-term deterioration of said insulating paper at a low temp. At first, deterioration products such as methyl formate, methyl acetate or the like are separated from the insulating paper used in oil or oil immersion. As one example of separation, a bubbling method by inert gas is effective. Next, the separated deterioration products are quantitatively analyzed by a gas chromatograph and the deterioration degree of insulating oil and the insulating paper is estimated from the dissolving amount thereof. By this method, the estimation of life is enabled. |
