Shufian, Abu 1 ; Islam, Riadul 1 ; Rahman, Md Mominur 1 1 Dept. of Electr. & Electron. Eng., American Int. Univ.-Bangladesh, Dhaka, American International University-Bangladesh, Department of Electrical and Electronic Engineering, Dhaka, 1229, Bangladesh firstname.lastname@example.org ; email@example.com ; firstname.lastname@example.org
Fertilizers (Triple superphosphate) and pesticide (fungicide and insecticide) are one of the major products used to increase the productivity of crops. As time passes the amount of pesticide in crops is not maintained fixed. Pesticide does react with water and the level of pesticide decreases day by day. Hence, it is important to know the present level of pesticide in soil and crops. TSP and pesticide (fungicide and insecticide) are used in this project as a sample of fertilizer and pesticide, cause of its high demand in Bangladesh. To detect the amount of TSP and pesticide in the oil sample, the conductivity property of TSP and pesticide (fungicide and insecticide) are used. Three separate solutions of TSP and pesticide (fungicide and insecticide) is made with water then AC source is applied to the solution instead of DC to avoid electrolysis of the given solution. Through the op-amp and two comparators, the final result is accomplished. Those two comparators, comparator 1 and comparator 2 were used to find the presence of 30%, 50%,70% TSP and Pesticide respectively. As result suggest, the resistance of the solution decreases with the incremental frequency. The compatible frequency for AC source is selected as 40 KHz. The reference voltage of comparator 1 is 1.4v and comparator 2 is 5v.