| 摘要 |
PURPOSE:To improve the measurement accuracy of a light transmitting method by finding a low transmission quantity time from information on variation in the light transmission quantity with lapse of time, regarding a low transmission quantity time less than a specific time as a time wherein the light transmission quantity does not decreases and correcting said information on the variation with lapse of time. CONSTITUTION:A light transmission quantity variation storage means 21 is stored with information on variation in voltage with lapse of time corresponding to the variation in light transmission quantity with lapse of time from an A/D converting circuit 6. An air bubble signal generating and storing means 22 reads the time variation information out of the means 21, compares it with a reference level from an air bubble reference level setting means 23, and converts the information into time variation information on whether or not there is an air bubble, so that the information is stored. A correction data generating means 31 reads air bubble information out of the means 22 to calculate a time wherein the light transmission quantity decreases, judges that all parts in the calculated time under a correction time set by a correction time setting means 40 are free from a decrease in light transmission quantity, and outputs temporary correction air bubble information. An air bubble diameter distribution function arithmetic means 32 calculates the deviation value of an air bubble diameter according to said information. The correction time is updated until the deviation value becomes minimum, and air bubble characteristics are calculated 50 from the current correction air bubble information. |
