To realize an accurate on-line measuring system for a trace of microorganism by determining a concentrating rate based on a predetermined target value and a predetermined directly measured quality value of water to be measured and then concentrating the water to be measured to that concentrating rate so that the concentration of microorganism is increased.
Stock water 1 in a lake or dam is sampled with a pump 10 and passed through a strainer in order to remove large dirt, e.g. sand and leaves, thus producing a water to be measured and then the turbidity thereof is measured 30. A concentrating rate determining unit 40 then determines a correct concentrating rate based on the turnbidity data and a predetermined target value using an apparatus 60 for measuring the image of microorganism and a concentrator 50 concentrates the water to be measured to that concentration rate. A unit 70 for calculating the concentration of microorganism calculates the concentration of microorganism in the nonconcentrated water to be measured based on the measured 60 quantity of microorganism and concentration rate of the water to be measured and the concentration of microorganism is displayed 80 along with the turbidity, concentrating rate and the quantity of microorganism. Since the water to be measured is concentrated to a level appropriate for measurement 60 of microorganism, efficiency and accuracy can be enhanced in the measurement.
WATANABE SHOJI
YAHAGI TOSHIO
YODA MIKIO
HARA NAOKI
YAMAKOSHI NOBUYOSHI
BABA KENJI
TERASONO KATSUJI
DAM SUIGENCHI KANKYO SEIBI CEN