Portable electronic embedded system ISFET based pH meter test kit for harumanis ripeness detection

Abstract

Measurement of pH in terms of Ionic Sensitive Field Effect Transistor (ISFET) and integration with the electronic embedded system is essential in agriculture processes especially in fruit ripeness monitoring, pH data analysis and fruit ripeness control applications. This research project is an alternative for determining the states of ripeness or maturity for harumanis using ISFET technology. The idea for implementing this research is based on the concept of determination of pH for harumanis by using conventional glass pH meter test kit. The kit shows that a sample of harumanis stores ions sensitive signal in terms of electrical signal. Therefore, the pH meter indicates that the harumanis has analog value and the embedded system converts this analog value to be displayed as digital value on the LCD display. As it turns out, there is a correlation between these pH properties and the maturity of harumanis. The pH of different types of harumanis maturity has been measured using pH meter test kit which is connected to an embedded system. This pH meter setup consists of ISFET pH sensor with a reference electrode for calibrating different types of harumanis sample. The ISFET pH sensor has shown that detection of different types of maturity levels for harumanis is feasible hence the sets of pH reading obtained are observed on LCD display. The sets of pH reading are analyzed in identifying time duration for harumanis maturity. Therefore a graph of pH for harumanis against duration of harumanis maturity can be produced, thus the process of harvesting harumanis is easier than as expected. ISFET provides a method to view the analog input from the impedance provided by the oscillator circuit. For digital display purpose, the data acquisition is sent to a personal computer via serial link. It displays digital pH meter by processing the digital output signal. Since the ISFET sensor has proved to give accurate and reliable measurements of the pH properties for harumanis, it is chosen as the standard measurement device in determining harumanis maturity level; under ripe, ripe or over ripe.