The 390B Series True RMS multimeters offer a comprehensive solution for general purpose measurement applications. Bundled with a complete set of accessories, these multimeters provide technicians and engineers with accurate results, data logging capabilities, and measurement features for evaluating a variety of electronics or electrical systems. The easy to read display features an analog style bar graph to help identify measurement trends or fluctuating signals. When working in low-light environments, the auto on/off backlight adjusts for best visibility while maximizing battery life. Dual line display capabilities enable two measurements or one measurement and a math function to appear on screen simultaneously. Advanced features like data logging records measurements to the meter’s internal memory at a user-specified sampling interval. Model 390B features wireless connectivity for logging measurement data directly to a smartphone or tablet while in the field. All models in this series provide convenient measurement monitoring and recording from a PC connected to the meter’s optical isolated USB interface. Additionally, measurements stored in the meter's internal memory can be exported using the provided PC application software.