This is by far the most sophisticated of the tools available currently in the Ryobi Tek4 cordless tools lineup. The Professional Digital Multimeter (RP4020) can measure AC/DC current and voltage, resistance, capacitance, and can check the forward voltage drop of a diode. It can test for continuity and has an internal speaker to give tones when buttons are pressed (and to indicate continuity). The voltmeter adheres to the Tek4 gray/green styling and includes an aluminum-style faceplate that is inset into the front of the unit, surrounding the mode selection dial, LCD screen and buttons. The LCD screen is backlit (a nice bright green) but has poor vertical off-axis response, so be sure to position the meter close to eye-level during use. The entire unit is covered mostly in the rubberized gray overmold which looks like it helps protect as well as provide a non-slip grip. On the back side, the Tek4 Digital Multimeter sports a kickstand and a flip out “Convenience Hook” that lets you hand the meter off of conduit or any other material with a slight lip. We also enjoyed the built in probe holders, which secured the probes perfectly when they were wrapped vertically around the entire meter and left connected.
The Digital Multimeter’s mode selection dial and buttons were easy to use, even with a gloved hand. We also liked the probes which had just the right length of cable to maximize their usefulness without making them clumsy. It did an accurate job of measuring voltage and current on our test bench, coming well within its range of accuracy for AC/DC current, resistance and capacitance. The continuity testing capability of this multimeter, however, was a little bit erratic, so be sure to push down firmly when testing for continuity and listen for that continuous tone.
Overall this is a decent multimeter, but less distinctive as a product than some of the other Ryobi Tek4 products. Our favorite aspect was the one-handed gloved use and the way it wraps up easily into a self-contained package. There are a lot of Multimeters on the market, but the rechargable nature of the RP4020 Tek4 system means that if you already have a suite of Tek4 tools, you would do well to add this to your collection.