... loose circle,measuring the pile,highways,tunnels,bridges and indoor rock,ultrasonic earthquake model test. With super magnetic flex ... positive trigger, negative trigger, positive / negative trigger, open circuit trigger, short-circuit trigger.;2. Channel: 1, 2, 4, 8, 16, ... ;6. Amplifier input impedance: 1KΩ;7. Launch pulse voltage: low voltage: 160V. High Voltage: 1KV;8. Sampling rate: 10-bit, 20MHz ( ...