1. Ngwongwo aha a na-akọ n'ime ebe a bụ ụdị ngwaahịa a, mana anaghị egosipụta ọdịiche nnwale nkịtị, yabụ ekwesighi iji ya maka ebumnuche nkọwapụta. A na-agbakọ ụkpụrụ.
2. Ekpebiri akụrụngwa anụ ahụ na ụdị mkpakọ kpụrụ akpụ nke edoziri n'usoro C nke ASTM D4703, Annex A1.
3. Dabere na ihe nkiri 0.025 mm na-emepụta na 4: 1 nha nha.