Low Resistance Measurement 01-OHM 02-OHM and Others LM317

Simple Circuit for measuring low resistance values. It is designed to measure low resistance values from 0.01 to 19.99 Ohms. The measurement circuit and the voltmeter must be fed from two separate power sources (battery). You MUST Use Two Separate 9 Volt Batteries in All These Circuits. Using a double-contact switch, you can connect both batteries to the circuit and voltmeter at the same time. You can use 100 mA, T0-92 version LM317LZ instead of TO220 case LM317.

The current drawn from the LM317 regulator must be adjusted to exactly 100mA. Use thick cable for the measuring probe or the terminal can be a socket style construction. Do not touch with hands during measurement, it will affect the result. For calibration, you can use resistors between 1.5 and 1.9 ohms. % tolerance gives better results.

Source: chemelec.com/Projects/Low-Ohm/Low-Ohm.htm