B&K Precision 2542B-GEN - Manual - Manual (Page 39)

Basic Operation
39
Press the channel key CH2, then press the Coupling softkey
until GND coupling is selected.
GND mode blocks both AC and DC components of the input
signal and connect the input to the ground level.
GND Coupling
BW Limit
Press the channel key CH2, then press the BW Limit softkey
to turn the bandwidth limit on or off for the selected channel 2.
When it is off, it passes both the high and low frequency
components.