... , waveform can real time observation, locking, save analysis.& built-in high-energy lithium battery, there is no external power supply ... than 85%Ø power: built-in lithium ion battery 12 V, 4000 mAh;Ø recharging voltage: input AC220V frequency 50 Hz, output DC + ... channel count: 4 channel, among them 2, 4 channel in intermediate frequency and low frequency only hasØ maximum signal amplitude: ± 50 VDC or ...