Digital pen: since the digital pen, for the ordinary pen has been rarely used, for the digital pen features more, such as not charged to check the broken line, distinguish between zero and fire, distinguish between positive and negative DC battery, determine whether the wire is short-circuited can be, so the gradual elimination of the ordinary pen, with the digital pen to distinguish between the fire line and the zero line, if you use the digital pen to measure directly with a pen to measure the fire line and the zero line, observe digital pen Voltage, if the display of the maximum voltage of 220V, proving that the firewire, if the display of the maximum voltage of 12V or 36V voltage, proving that the zero line!

For the multimeter will have an AC voltage gear, for AC voltage gear can measure the voltage of alternating current, measure the voltage with a red and black pen, respectively, placed on the fire line and the zero line, it will show its voltage, but the measurement of voltage, to be placed in the appropriate gear, such as the measurement of household 220V, 380V voltage, the multimeter should be placed in the AC voltage of 700V gear!