The Development of A Device to Measure the Ripeness and Internal Quality of Watermelons

Recently , it has been popular for family use to sell a watermelon by the piece such as a half or a quarter. Therefore, it has been necessary to detect and sort out hollow or overripened watermelons before they are shipped. Previously, inspection and rejection of hollow or overripened watermelons were carried out by skilled inspectors with their experience and intuition based on the traditional slapping method. In recent years many inspectors have became older and are going to retire. Thus automatic quality measuring devices have to be developed. There are many reports on the measurement of internal quality for watermelons with non-destructive methods. However, there is no online device to detect and measure both hollow and ripeness of watermelons until now. We have developed the model MWA-9002 online device to detect hollow and measuring the ripeness of watermelons by acoustic impulse. The developed of this devices has enables accurate distinction and rejection at the same level of the skilled inspectors, and also has saved labor. Nowadays nine automatic watermelon sorting and packing facilities applied this device have installed in Japan.