Philips PM3320 Operating Manual page 143

4.5.4
4.5.5
4.5.5.1
4.5.5.2
4.6.5.3
4-127E
Use of probes
The 10:1 passive probes must be properly compensated before use to avoid pulse distortion or
amplitude errors at high frequencies.
For correct adjustment, refer to section 8.1.1.4.
Vertical
As channels A and B are identical, only the procedure for channel A is described.
Vertical mode
— Press the green pushbutton AUTO; a square wave with a vertical amplitude of a few divisions
becomes visible on the screen.
- Press pushbutton VERTICAL MODE. Check that channel A is selected.
- Press softkey A and B. Channel B is visible as a straight line.
- Press pushbutton VERTICAL COUPLING.
— Press softkey GROUND of COUPLING B.
- Press pushbutton VERTICAL MODE.
- Press softkey ADD; only the square wave is visible.
— Press softkey A. Check the square wave for minimum jump in vertical direction (< 0,3 div.).
- Press softkey A-INVERT; the square wave is inverted.
- Press softkey A-INVERT; the square wave is inverted again (normal).
~ Press softkey PROCESSING; the VERTICAL PROCESSING menu is visible.
- Press softkey MIN / MAX. Check that the straight horizontal parts of the square wave become
more frayed.
- Press softkey MIN / MAX again; MIN / MAX is off.
- Press softkey RETURN; the VERTICAL MODE menu appears.
Vertical coupling
- Press pushbutton VERTICAL COUPLING. Check that AC coupling is selected.
- Press softkey AC DC of VERTICAL COUPLING A; DC is selected.
~ Check that the displayed square wave is shifted upwards with zero line on vertical
midposition.
— Press softkey GROUND of VERTICAL COUPLING A. Check that the input signal is switched
off, a straight line is visible on the screen.
~ Press softkey AC. DC of channel A; DC is selected and the square wave is visible again.
- Press softkey OFFSET of channel A.
- Press softkey UP and DOWN and check if the signal moves up and down.
Vertical controls
— Press UP/DOWN control AMPL/DIV on it's left side. Check that the amplitude of the square
wave on the screen decreases.
— Press UP/DOWN control AMPL/DIV on it's right side. Check that the amplitude increases.
- Turn VARIABLE left. Check that the amplitude decreases and pilot lamp UNCAL lights up.
- Turn VARIABLE right. Check that the amplitude increases and pilotiamp UNCAL extinguishes.
- Turn SHIFT to the right to move the signal up and to the left to move it down,