두께 팽윤율은 두께를 미리 측정한 시험편을 냉수에 24시간 침지시킨 후, 증가한 두께를 측정하여 구하였다.
Thickness inflammation ratio had been obtained by measuring the increased thickness after immersing the test piece of which the depth had been formerly measured in cold water for 24 hours.