The Fluke 88-5 is a handheld digital multimeter that measures voltage, current, and resistance. It is designed to solve the problem of inaccurate readings caused by ghost voltage, which can occur when a multimeter is used to measure voltage in a circuit that is not completely isolated. The Fluke 88-5 uses a true-rms sensing circuit to measure voltage, which eliminates the effects of ghost voltage and provides accurate readings even in noisy environments.