Posted on Monday, January 10, 2011 • Category: Test and Measurement
A very simple circuit to measure low resistance values from 0.001 up to 1.999 Ohm. With a "Direct Resistance Readout in Ohms". You must use two separate batteries. One for the DMM and one to supply power to the LM317LZ. I recommend the LM317LZ, which is the 100 mA, T0-92 version of the normal LM317. But you can also use the LM317, in the T0-220 package, if you want. The trimpot must be set precisely to deliver 100.0 mA out to get truly accurate resistance measurements.
So you need a very accurate Milli-Amp Meter to adjust this Correctly.
(And like Any Test Equipment, This Calibration should be Re-Checked once a year or so.)
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