Oscilloscope Input Channel and Input Coupling Selection
(1) Input Channel Selection
There are at least three ways to select the input channel: channel 1 (CH1), channel 2 (CH2), and dual channel (DUAL). When channel 1 is selected, the oscilloscope only displays the signal of channel 1. When channel 2 is selected, the oscilloscope only displays the signal of channel 2. When DUAL is selected, the oscilloscope displays the signal of channel 1 and channel 2 at the same time. When testing signals, first connect the ground of the oscilloscope to the ground of the circuit under test.
According to the selection of the input channel, plug the oscilloscope probe into the corresponding channel socket, the ground on the oscilloscope probe is connected to the ground of the circuit under test, and the oscilloscope probe touches the point under test. There is a two-position switch on the oscilloscope probe. When this switch is set to "×1" position, the measured signal is sent to the oscilloscope without attenuation, and the voltage value read out from the fluorescent screen is the actual voltage value of the signal. When this switch is set to the "×10" position, the measured signal is attenuated to 1/10 and then sent to the oscilloscope, and the voltage value read out from the fluorescent screen is multiplied by 10 to be the actual voltage value of the signal.
(2) Input coupling method
There are three choices for input coupling: AC (AC), ground (GND), DC (DC). When "Ground" is selected, the scan line shows the position of "Oscilloscope Ground" on the fluorescent screen. DC coupling is used to determine the absolute DC value of signals and to observe very low frequency signals. AC coupling is used to observe AC and AC signals with DC components. In digital circuit experiments, the "DC" mode is generally selected to observe the absolute voltage value of the signal.
