| 摘要 |
PROBLEM TO BE SOLVED: To provide a drain water detecting method for a freezing-refrigerating showcase improving measuring accuracy by measuring a distance based only on data in a range where a distance can be accurately measured (a reflex time until reflected and returned) when detecting a full level state of drain water by an ultrasonic sensor, while, as to data in a range where the distance cannot be accurately measured, clarifying the cause. SOLUTION: In the ultrasonic sensor installed above a drain receiver, the direct reflected wave of a reflection signal from the ultrasonic sensor radiating to the water surface of drain water is input to compute a distance from the reflex time from the water surface of drain water to the sensor. COPYRIGHT: (C)2008,JPO&INPIT |
