The following is a brief description of the ASTM D1534 (Gervin) method
for the neutralization number test: Pour the oil sample into a glass cylinder
furnished with the Gervin test kit. Single doses of KOH are furnished in
sealed ampules with the dosage indicated on the ampules. For example,
if the oil level in the glass cylinder is up to mark 10, then number 3 ampules
equals 0.3 mg of KOH gram of oil; a number 6 ampules equals 0.6 mg of KOH,
and a number 15 equals 1.5 mg of KOH.
The pint bottles contain neutral solution to be put in the measured sample
before adding the KOH. This solution washes the oil and the KOH can then
act on the acids more readily. The neutral solution contains a color-changing
indicator. If any KOH is left after the acids are neutralized, the indicator is
pink. But if the KOH is all used up, the indicator is colorless like water.
4.2.2.3