Utilizing a multimeter is the most straightforward technique, as it provides direct readings of the voltage output. Fluke recommends using the Fluke 117 Electrician's Multimeter or Fluke 283 FC CAT III 1500 V Digital Multimeter to test solar modules. Here's how a technician tests solar modules with a multimeter:. Digital multimeters (DMMs) are essential tools for solar professionals, enabling them to measure electrical parameters and ensure the optimal performance of solar installations. Also, a simple voltmeter won't work here.