| 摘要 |
PURPOSE:To control the gain of an amplifier and to prevent the amplified reception signal from deviating from a dynamic range by providing a peak holding circuit, arithmetic processing circuit and timing control circuit to a shell thickness gage for a continuous casting billet utilizing an ultrasonic wave. CONSTITUTION:The max. value of amplitude is detected from the reception signal passed through an amplifier 10 and gate circuit 11 of a shell thickness gage by a peak holding circuit 22, and from the three values: the gain of the amplifier 10, the set value 25 of an arithmetic circuit 23, that is, the dynamic range of a setting circuit 12 for passage time, the value obtd, by processing with the circuit 23 is the gain of the amplifier 10 for the next recetion signal to be detected by an electromagnetic ultrasonic wave receiver 2. The timing at which the circuit 22 and the circuit 23 operate is controlled by a timing control circuit 24 according to the command from a pulse generating circuit 8 so that the reception signal is processed until the succeeding reception signal is detected after detection of said signal. |
