| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an ultrasonic concentration meter capable of measuring a concentration of a fluid accurately without using a temperature sensor by using the principle of a time difference type ultrasonic flowmeter. <P>SOLUTION: An average period of vibration is calculated from zero-cross points in a free vibration part Wb of a reception waveform W with respect to a water solution having certain temperature and concentration. This average period depends only on temperature. By emitting an ultrasonic beam from upstream and from downstream into a water solution that is a fluid, acoustic velocity of the water solution is obtained. Because the acoustic velocity is proportional to the concentration and varies by the temperature of the water solution, a temperature-corrected concentration can be calculated from the obtained acoustic velocity and temperature. <P>COPYRIGHT: (C)2012,JPO&INPIT |
