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Nondestructive Measurement oOf Fruits Quality by Electrical Impedance

通过电阻抗无损测量水果质量

基本信息

批准号：
61460221
负责人：
KATO Koro
金额：
$ 1.98万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

项目摘要

The object of this study is nondestructive electrical inspection of internal quality of fruits and vegetables. On-line real time system which can measure vector impedance of fruits and vegetables and analyze the dielectric properties has been developed. Obvious differences in dielectric properties were distinguished between fresh and spoiled or damaged fruits in the range of 10Hz to 13MHz. According to rot or damage, resistance of fruits, impedance, and reactance decrease sharply, and capacitance and dielectric loss factor increase. Among these impedance parmeters, correlation between resistance Rs and freshness or maturity is the most obvious in nondestructive measurement. Thus, the freshness of fruits can be measured nondestructively and contactively by resistance Rs.Next, we tried noncontacting measurement of resistance of fruit by capacitive connection. It became clear that if the fruits are spherical and same size, the freshness can be measured nondestructively and noncontactively … More .The most difficult problem of inner quality measurement by dielectric property is that the measured values of impedance parameters are influenced by the shape and the size of fruits. To solve this problem, we tried to measure the dielectric properties of fruits by comparison with those of water. For example, when we sink fruit into water in a container which has electrodes on both sides , if the specific resistance of fruit is greater than that of water, the resistance between electrodes increases by comparison with the value before sinking. If the specific resistance of fruit is lower than that of water, the resistance between electrodes decreases. The magnitude of change depends on the size and shape of the fruit but the direction of change does not depend on the shape or size of the fruit or vegetable. Accordingly, we can separate fruits by specific resistance, preparing water which has a threshold value of specific resistance. By this metod, we can easily measure the quality of fruits and vegetables which have complex shapes. Less

本研究的对象是果蔬内部品质的无损电学检测。研制了一套可在线真实的实时测量果蔬矢量阻抗并分析其介电特性的系统。在10 ~ 13 MHz频率范围内，新鲜水果与腐败或受损水果的介电特性存在明显差异。果实腐烂或破损后，电阻、阻抗、电抗急剧下降，电容和介质损耗因子增大。在这些阻抗参数中，电阻Rs与新鲜度或成熟度的相关性在无损测量中最为明显。因此，水果的新鲜度可以通过电阻Rs非接触式测量。接下来，我们尝试了非接触式测量水果的电阻电容连接。很明显，如果水果是球形的，大小相同，新鲜度可以非破坏性和非接触式测量 ...更多信息利用介电特性测量果实内部品质的最大难题是阻抗参数的测量值受果实形状和大小的影响。为了解决这个问题，我们试图通过与水的介电特性进行比较来测量水果的介电特性。例如，当我们将水果放入两侧都有电极的容器中的水中时，如果水果的电阻率大于水的电阻率，则电极之间的电阻与下沉前的值相比会增加。如果水果的比电阻低于水的比电阻，则电极之间的电阻减小。变化的幅度取决于水果的大小和形状，但变化的方向不取决于水果或蔬菜的形状或大小。因此，我们可以通过比电阻来分离水果，制备具有比电阻阈值的水。通过这种方法，我们可以很容易地测量具有复杂形状的水果和蔬菜的质量。少