JPS55155277A - Ultrasonic type snow deposition meter - Google Patents

Abstract

PURPOSE:To automatically perform compensation and enable high-accuracy measurement even if the quality of snow changes, by maintaining the slice level of a comparator at a prescribed ratio to the level of received waves. CONSTITUTION:A snow deposition meter comprises a control section 1 made of a microcomputer, a transmitting section 2, a receiving section 3, a D/A converter 4 and a counter 5. A reference signal 3e is set at the first slice level after tone burst waves are emitted from a tone burst generation circuit 2b. The reference signal is shifted to the second slice level when time corresponding to a prescribed number of waves has elapsed after wave reception. The counted value of the counter 5 is cleared to zero by the control section 1 simultaneously with the shifting to the second slice level. When a prescribed time has elapsed since the shifting of the reference signal 3e to the second slice level, the counted value of the counter 5 is read. The level of the reference signal 3e is slightly increased or decreased depending on the read counted value to cause the slice level to follow up the level of received waves. As a result, the accurate depth of deposited snow can be determined through an output terminal 1a.