The use of a DLRO (Digital Low Resistance Ohmmeter) versus a DMM (Digital Multi-Meter)

One of the simplest and most common electrical tests performed by electricians and test technicians today is the continuity test. This test option is featured on most multi-meters and insulation testers. The continuity test is simple to perform – connect two leads across opposite ends of the item under test (IUT), press the test button, and the instrument quickly provides a resistance reading. A low reading is considered good and a high reading bad. In fact, this test is so simple that it is often used for applications that actually require a more demanding performance from the test instrument. In this note we’ll look at some of these applications and the resulting requirements that highlight the differences between a low resistance ohmmeter (DLRO) and a digital multi-meter (DMM) – and the importance of using a DLRO to find issues that a DMM cannot.