| 摘要 |
PURPOSE:To measure the volume of ice directly without using the concentration of an impurity by transmitting an ultrasonic wave from the bottom surface side of a region and then obtaining the propagation time until the reflection wave from the interface between a mixture of ice and water and air is received. CONSTITUTION:An excitation circuit transmits ultrasonic pulses by exciting a wave transmitter 102. The transmitted ultrasonic pulses are propagated from a bottom part of a tank 2 toward an upper part and is reflected by the interface between a mixture of ice and water and air. The reflection wave is received by a wave transmitter 104 and is amplified 116 and detected 118 and then is fed to a comparator 120. A gate circuit 122 causes a gate pulse to rise according to a signal from a main synchronization circuit 114 and then to fall by receiving an echo detection pulse. A counter 124 counts the clock signal while the gate pulse is at high level, detects the ultrasonic propagation time from transmission from the wave transmitter 102 to reception by a wave receiver 104, thus obtaining the virtual volume of ice by an information processing part 300. |
