To prevent marine pollution by oils discharged from ships, the evaluation of the practical performance of oil content meters has been required and the international specifications of the performance test for the meters have been recommended by IMCO.
In the paper, the technical method for supplying oil-water mixture of the specified concentration to the meters was investigated. The characteristics of the oil contents in the mixture supplied by a test equipment were obtained.
The technical measures to get the small fluctuation in the oil contents were as follows:
a) The homogenizing power was kept high enough to disperse highly viscous oil into water phase.
b) The mixing effect was improved by providing the test equipment with adequate tank volume and circulating flow.
c) Plunger pump was used for supplying oils, and pulse in oil flow was absorbed by air-damper.
d) The inner diameter of oil injection needle was made small to get fine oil droplets.
e) The high flow rate was maintained to drive the oil pump in higher range of the oil flow rate.
The fluctuations in the oil contents were between 3.2% and 14.3% of the mean values for three kinds of oils.