After that, chemical contents of palm oil are analyzed by using Partial Least Squares Regression (PLSR) models .Besides imaging technology, a capacitive-based concept of grading method is proposed in . The capacitive concept is applied to measure the dielectric properties of the oil palm fruit. This measurement method yielded 5% accuracy for the dielectric constant (��) and 3% for the dielectric loss (��). The capacitive method is similar to the other methods, where supporting equipment is needed and it is not suitable for outdoor testing.In the prevailing research works, no grading methods using an inductive concept is proposed. An inductive concept non-destructive grading method is proposed in this research work, based on the moisture content of the oil palm fruit.
The permeability value of water is 1.2566270 �� 10?6. Thus, with a low permeability value compared to other materials, such as metals, a high frequency range is used in the measurement. This proposed inductive method has great potential for use in outdoor testing [32�C34]In this paper, investigation on the oil palm ripeness sensor based on the resonant frequency (fr) is presented. Inductance values in the high frequency range are used to determine the ripeness of the oil palm fruits which are then categorized into ripe and unripe fruits. The frequency characteristics of the sensors are studied and the fr of air (fra), ripe fruit (frr) and unripe fruit (fru) are analyzed. Initially, the value of frr and fru is normalized to fra.
Then, the deviation between the mean value in the normalized resonant frequency (Nfr) between the air (Nfra) and ripe fruit (Nfrr) as well as between air and unripe fruit (Nfru) are observed and analyzed for the effect of the size of the sensor and the coil diameter size affecting the sensitivity of the sensor, which is determined by the deviation in the mean value between Nfra and Nfrr as well as in between Nfra and Nfru. The larger the deviation from the mean value the more sensitive is the sensor. In this study, twenty sensors with different sensor sizes as well as different coil diameter sizes are built. Looking into the effects of coil diameter, the results portray a uniform pattern throughout the testing. It is observed that the Nfrr leads the Nfru. The value of the Nfr decreases as the air coil length is increased.
As for the effects of air coil length, the differences between the ripe to unripe samples increase as the Drug_discovery air coil length increases. The results from this study play an important role in designing the air coil structure as it will improve the sensitivity of the oil palm sensor to determine the maturity of the oil palm FFB as well as the ripening process of the fruitlets. Nevertheless, the inductive oil palm ripeness sensor method offers a few advantages such as it is a passive type sensor, reduces time consumption and is an accurate grading system.