| 摘要 |
PURPOSE:To improve the efficiency for measurement without a fine adjusting operation prior to measurement by measuring the time difference between the echo reflected from the rear of a steel plate of a long-side mold and the echo reflected from the surface of a pad after making incident on a water film and calculating the thickness of the water film. CONSTITUTION:The ultrasonic wave pulse transmitted by an ultrasonic wave probe 6 is reflected by the surface of the mold steel plate 2 and the surface of the base pad 1 and returns again to the probe 6. On the other hand, the ultrasonic wave pulse transmitted from an ultrasonic probe 6' is reflected by the surface and base of a reference steel plate 2' and the surface of the bottom plate of a vessel 20 contg. the plate 2' and returns again to the probe 6'. The waveform extracting only the echoes 52, 52'... past the water film is conducted together with the echo 51 reflected once by the base of the mold steel plate to a time measuring device 11, where the time difference between the echoes 51 and 52 is measured. The thickness of the water film is calculated from the measured value and the underwater sound velocity value. The working efficiency is thus improved without the need for the fine adjustment operation prior to the measurement. |
