3.4.2 Separating the Signal from Noise
To reduce random noise in the oscilloscope display, follow these steps:
●
Press
the ACQUIRE button to display the acquire menu.
●
Press
the Acquisition option button or turn the Universal knob to
select Average.
●
Press
the Averages option button to see the effects of varying the
number of running averages on the waveform display.
Averaging reduces random noise and makes it easier to see the details of a signal.
3.5 Triggering on a Video Signal
Observe the video circuit in a piece of medical equipment and Use the video trigger
to obtain a stable display.
3.5.1 Triggering on Video Field
To trigger on the video fields, follow these steps:
●
Press
the TRIGGER MENU button to see trigger menu
●
Press
the top option button and select Video.
●
Press
the source option button and select Ch1.
●
Press
the Sync option button and select Odd Field or Even Field.
●
Press
the Standard option button and select NTSC.
●
Turn
the horizontal S/Div knob to see a complete field across the screen.
●
Turn
the vertical Volts/Div knob to ensure that the entire video signal is
visible on the screen.
To trigger on the video lines, follow these steps:
●
Press
the TRIGGER MENU button to see the trigger menu
●
Press
the top option button and select Video.
●
Press
the Sync option button and select Line Num and turn the universal
knob to set a specific line number.
●
Press
the Standard option button and select NTSC.
●
Turn
the S/Div knob to see a complete video line across the screen.
●
Turn
the Volts/Div knob to ensure that the entire video signal is visible
on the screen.
3.5.2 Triggering on Video Lines
3.6. Application of X-Y function
Viewing Impedance Changes in a Network
Connect the oscilloscope to monitor the input and output of the circuit
To view the input and output of the circuit in an XY display, follow these steps:
●
Press
the CH 1 MENU button and set the Probe option attenuation to 10X.
●
Press
the CH 2 MENU button and set the Probe option attenuation to 10X.
●
Set
the switch of the probe to 10X.
●
Connect
the channel 1 probe to the input of the network, and connect the
channel 2 probe to the output.
●
Press
the AUTO button.
●
Turn
the Volts/div knobs to display approximately the same amplitude
signals on each channel.
●
Press
the DISPLAY button.
●
Press
the Format option button and select XY.
The oscilloscope displays a Lissajous pattern representing the input and output
characteristics of the circuit.
●
Turn
the VOLTS/DIV and VERTICAL POSITION knobs to optimize the
display.
●
Press
the Persist option button and select Infinite.
●
Press
the Intensity or Brightness option buttons and turn the Universal”
knob to adjust the contrast of the screen.
●
Apply
the Ellipse method to observe the phase difference between the
two channels
D
C
A
B
signal
must
be
centered
in
X
108
Digital
S
torage
O
scilloscope
Digital Storage Oscilloscope
109
The signal must be
medical horizontal
Sin =A/B or C/D where =phase shift (in
degrees )between the two signals From the
formula above ,you could get:=arcsine
(A/B) or arcsine (C/D)If the main axis of
the ellipse is at Ⅰ and Ⅲ quadrant , must
be in the range of (0～/2) or (3/2～2).
if the main axis is at Ⅰ and Ⅲ quadrant,
must be in the range of (/2～) or
(～3/2).
