| 摘要 |
PROBLEM TO BE SOLVED: To realize a method for accurately measuring a liquid level by measuring acoustic velocity under a measuring condition and directly or indirectly utilizing the acoustic velocity value, independent of containers or the kinds of contained liquid and the variation of temperature of the liquid. SOLUTION: The target type liquid level measuring method relating to this invention is characterized that a first target T1 and a second target T2 are arranged in liquid 4 contained in a container 2 in a state being shifted in the depth direction of the liquid, a ultrasonic pulse is applied to a bottom wall back surface 16 of the container 2, reflected signals of the ultrasonic pulses from the first target T1, the second target T2, and a liquid surface 14 are received, and the liquid surface height H is measured from the received time information (t1, t2 and t3) on the reflected signals and the position information (Y1 and Y2) on the first target and the second target. Acoustic velocity V in the liquid is derived from the received time information and the position information, and the liquid surface height H is measured by directly utilizing the acoustic velocity. |
