♦ For the vertical layer direction electric strength at 90°c ±2°c oil, you can select either in 20spressure rising-up gradually test
requirement or in 1mm withstand pressure test requirement. For the material meeting with requirement of either one, its vertical
layer direction electric strength at 90°c ±2°c oil is deemed to meet with this standard requirement.
♦ If the arithmetical mean of measured thickness of specimen (specimen) is between two thickness values in table, its indicated
value should be calculated out by interpolation. If the arithmetical mean of measured thickness is less the min. thickness
indicated in table, its limit value of electric strength is equal to the value of min. thickness. If the nominal thickness is 3mm
and the arithmetical mean value of measured thick is more than 3mm, its electric strength is taken out according to 3 mm thickness
limit value.