PURPOSE: To enable to perform a measurement by a non-dispersion optical system, to miniaturize and lighten a device, and to improve maneuverability, by making a pretreatment through addition of alkali to ballast waer to be measured.
CONSTITUTION: If alkali such as KOH and the like is added to ballast water to be measured, the alkali reacts with acetone cyanohydrin in ballast to produce acetone. The concentration of the acetone is measured by absorptivmetry through utilization of ultraviolet rays with a wavelength of about 253.7nm to measure concentration of acetone cyanohydrin contained in the ballast water. Additionally, absorbance is measured before alkali is added, and a measurment is made on a background due to a contaminating component to make a correction. This permits the more reliable measurement of concentration of acetone cyanohydrin.
AKIYAMA SHIGEYUKI
YONEDA ARITOSHI
