| 摘要 |
PROBLEM TO BE SOLVED: To provide a means for preventing the phenomenon that an ultrasonic oxygen densitometer shows an oxygen concentration higher than a real value at the time of a reduction in flow rate when the oxygen concentration of the outlet gas of an oxygen densitometer using a nitrogen adsorbing material is analyzed by the ultrasonic oxygen densitometer using an ultrasonic element. SOLUTION: In the ultrasonic oxygen densitometer, since the adsorption of oxygen begins when a use flow rate lowers and the adsorption of nitrogen is completed, the oxygen concentration changes from rising to falling. This change point corresponds to the oxygen concentration of 94.5%. An oxygen concentration measuring means uses the ultrasonic oxygen densitometer characterized in that the oxygen concentration is precisely analyzed by using two different operational formulae across an ultrasonic propagation speed at this time. COPYRIGHT: (C)2006,JPO&NCIPI
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