| 摘要 |
PURPOSE:To improve the accuracy of measurement of thickness of oil films, by using ultrasonic transmitting and receiving units attached to a stationary electrode and a follow-up needle, whereby the thickness of an oil film can be calculated on the basis of distances between the ultrasonic transmitting and receiving units and the oil surface, and an amount of displacement of the follow-up needle. CONSTITUTION:Let d1, d2 equal to distances between two ultrasonic transmitting and receiving units 9a, 9b and the surface of the water before the flooding of oil 7 occurs. Let d5, d3, d4 equal to the displacement of a follow-up needle 4 and distances between the transmitting and receiving units 9a, 9b and the oil surface, respectively, after the flooding of oil 7 has occurred. The amount of displacement of liquid level after the flooding of oil 7 has occurred may be determined in accordance with an equation, ds=d1-d3, on the basis of a detection value from the transmitting and receiving unit 9b which is attached to a stationary electrode 5. The amount of liquid level after the flooding of oil 7 has occurred, which is determined on the basis of displacement d5 of the follow- up needle 4 and a detection value from the transmitting and receiving unit 9a attached to the follow-up needle 4, is in accordance with an equation ds'=d2-d4-d5. Then, ds, ds' are subjected to operational comparison in an operational comparison circuit 21. When ds, ds' are not in agreement with each other, warning is given from an alarm 22 as a signal of abnormal operation of the apparatus. At this time, it is necessary that the apparatus be inspected. An accurate thickness of oil film is determined by conducting operation dT=d2-d4 in an operation circuit 18. |
