Analysis of Design Test for Current and Voltage Meters with a Constant Current Source for a Resistivity Meter

Resistivity meter is a tool used to measure the resistivity of a medium or material by injecting a current into the earth. The main circuit contained in the resistivity meter is a current source, current meter, voltage meter, and data viewer. The current source is part of an electrical device that functions to conduct electric current. In this case, the constant current application is needed in resistivity measurement because the medium to be measured is the earth. There is a layer of earth rock which causes the instability of the current when it is injected into the earth. This study aims to design a current and voltage meter with a constant current source based on Arduino nano using a Shunt Resistor and ADS1115 as a current and voltage meter. The results of several tests showed that the constant current source circuit can be applied to the current variations of 1.9 mA, 12.5 mA, 18.4 mA, 62.5 mA, 83 mA, and 125 mA. This constant current variation can work on a resistance value of 20 Ω to 680 Ω. The application of constant current sources to current and voltage measurements is successful at a constant current variation of 1.9 mA with a variation of resistance from 4.7 Ohm to 1 MOhm.