Using the Fluke NORMA 6004+ Portable Power Analyzer is a breeze. First, make sure the 5000mAh Li - ion internal battery is charged if you're not using an external power supply. You can use it continuously for up to 6 hours on battery power. When taking measurements, ensure you're in a proper safety - rated environment, like CAT III 1000V or CAT IV 600V. You can measure three - phase AC and DC power, and with 3 or 4 channel models, you can measure three - phase power and DC output power at the same time. Just connect the voltage and current inputs on each channel. As for maintenance, keep the device clean and dry. Avoid exposing it to extreme temperatures. If you're not using it for a long time, store the battery in a cool, dry place. Also, make sure to update the software regularly for optimal performance.