APPARATUS FOR DISCRIMINATING PRESENCE AND DEGREE OF CAVITY OF OBJECT TO BE MEASURED IN NONDESTRUCTIVE MANNER AND VOLUME MEASURING APPARATUS

摘要

PURPOSE:To discriminate the presence and the degree of the cavity of an object to be measured in a nondestructive manner by providing a means measuring the wt. of the object to be measured, a means measuring the volume thereof, a means calculating the specific wt. of the object to be measured from the measured values and a means comparing the specific wt. with a reference value. CONSTITUTION:A member 1 on which an object to be measured such as fruit (a) is placed is constituted of an elastomer such as conductive rubber and used as a main electrode and the cover body 2 covering the fruit (a) is used as an earth electrode composed of a conductor to constitute a volume measuring apparatus. Three surfaces of the fruit (a) are surrounded by the cover body 2 and high frequency voltage is applied across the member 1 and the cover body 2 from a capacitance meter 3 to measure the capacitance Cf of the fruit (a) and the capacity Ck of the cavity between the cover body 2 and the fruit (a). The detected capacitance Cx between both electrodes is calculated according to formula I and, when the capacity is made zero or minute, Ck becomes + and the electric capacity Cf of the fruit (a) itself is measured and the change of the capacity Cf related to the moisture or internal state of the fruit (a) is detected.