Precautions while using Cathode Ray Oscilloscope

Horizontal sweep section

Sweep time cm Selects desired sweep rate from calibrated steps or admits external signal to horizontal amplifier.
Sweep time cm Variable Provides continuously variable sweep rates. Calibrated position is fully clockwise.
Position Controls horizontal position of trace on screen.
Horizontal Variable Controls the attenuation reduction of signal applied to horizontal aplifier through Ext. Horiz. connector.