Problems of testing oil content monitors to the MARPOL 73/78 specifications

Abstract

This Chapter deals with the physical difficulties involved in testing oil content monitoring systems to the given IMO specifications, such that they can gain approval for shipboard installations. Over the years several recommendations on performance specifications for oily-water separating equipment and oil content meters have been made. These are summarised, with comments, in Table 5.1. Historically, the procedure began with Resolution A. 233(VII) in 1971. These test specifications were the first approach made as a result of international inputs to IMO. Further contributions were made in 1975 by the various shipping representative groups, such as the Oil Companies’ International Marine Forum—OCIMF, Berto^[5.1], at MEPC III. Several investigations provided a basis for these and subsequent test specifications (i. e. A.393(X)). For example, tests were carried out on several oil types by the US Coastguard to investigate the ‘sheen on the water’ criteria, under different lighting conditions, to provide the limit for inshore discharges at near 15 ppm.