Fluke 1577 insulation multimeter fluke fluke 1577 the fluke 1577 insulation multimeter combines a digital insulation tester with a full featured true rms digital multimeter in a single compact handheld unit which provides maximum versatility for both troubleshooting and preventative maintenance p whether you work on motors generators cables or switch gear this multimeter is ideally suited to help you with your tasks and at a cost that is far less than buying the two products p fl