... 12-lead ECG signals;Selectable Multi-recording modes,Three-channel, 3-channel+Rhythm, 60 Sec Compressible waveform record; Three-channel waveform ... μA Calibrating voltage 1mV±2% Voltage tolerance ±500mV Time constant >3.2s Frequency response 0.05 ~150Hz Noise level ≤15μVp ... Inter-Channel Interference ≤0.5mm Paper speed 25,50mm/s(±3%) 25,50mm/s(±3%)Sensitivity AUTO,2.5,5,10,20mm/mV Recording ...