The Fluke 1587 FC is a 2-in-1 tool combining a digital insulation tester (megohmmeter) and a true-RMS digital multimeter, designed for troubleshooting and preventative maintenance on motors, generators, cables, and switchgear. It measures insulation resistance (\(0.01\ M\Omega\) to \(2\ G\Omega\)), voltage, current, frequency, and temperature, plus specialized tasks like VFD measurements and PI/DAR timed ratio tests.