METHOD FOR CHANGING MEASURING INTERVAL OF GAS MIXING RATE IN A DEVICE FOR MIXING GAS IN LIQUID

摘要

PURPOSE:To make stable a rate of gas mixing by comparing an observed value and a set value of a gas mixing rate and changing the time interval for measuring the gas mixing rate automatically. CONSTITUTION:A comparing and instructing section 34 which compares an observed value Xa of gas mixing rate with a set value Xb and a subset value Xc and controls an opening and closing time of a gas solenoid valve 18 basing on the results of comparison, is provided to a controlling device 31. If the observed value Xa is <= subset value Xc, a timer TM1 for measuring the measuring interval T1 is started automatically to open a gas solenoid valve 18 during a primary measuring interval T1. If Xa is between Xc and Xb, the timer TM1 is changed over to a timer TM2 for measuring the secondary measuring interval T2 to open the gas solenoid valve 18 during the secondary measuring interval T2. If Xa is >=Xb, the gas solenoid valve 18 is closed during the secondary measuring interval T2.