The LEFT side of the dial's scale is for AC testing, indicated by a "V" with a wavy line (alternating current). The RIGHT side of the dial's scale is for DC, indicated by a "V" with a constant line (steady current) over a dashed line (AC current rectified into DC current). As for testing a circuit's current, first note that this meter only reads up to 10 milliamps (mA) on the "10" setting (bottom right of the dial), or 250 milliamps on the "250" setting, depending on the dial's setting. Testing currents greater than these two respective settings will fry your unit's fuse (located inside the unit; the fuse can be replaced) or will damage the unit altogether. This tester is only good for low-current testing of circuits powered by small batteries (AAA, AA, C, D, 9V, etc.), or common 110V AC/DC transformers (wall warts, as some call them--check the amperage output listed on the outside of the DC transformer to ensure it does not exceed 250 mA). Before you test for amps, calibrate your multimeter's needle by setting the dial to the X1k (resistance) setting, touching the metal tips of the black and red leads together firmly, and then adjusting the adjustment dial on the left side of the multimeter until the needle is dead-centered on the zero (far right) of the analog scale. Okay, to test for amperage in a circuit: (1) first REMOVE (or DISCONNECT) the negative side battery wire from the negative battery terminal/connector of your circuit to be tested. (2) Next, on your multimeter, set the dial to measure either 250mA or 10mA, as needed. (3) Ensure the multimeter's black lead is connected to the "COM" plug to the left side of the multimeter's dial, and that the red lead is connected to the VmAΩ plug to the right side of the multimeter's dial. (4) Then attach/touch the multimeter's black lead tip to the battery's negative battery post (or the transformer's negative connector). (5) Finally, touch the multimeter's red lead tip to the DISCONNECTED negative battery wire of the circuit to be tested. The current (milliamperes) will be indicated by the multimeter needle. Note: It is very important that the circuit you are testing is NOT energized during this test! The negative terminal of the battery must be disconnected from the negative battery connector of the circuit you are testing. Failure to skip this step may damage your multimeter.
Date published: 2017-03-24