4 - 32 HOW TO USE THE INSTRUMENT
ACQUIRE AVERAGE
The
average
function averages the input data over a number of successive
acquisitions. The average function is used to reduce the influence of random
noise in the input signal. There is no loss of bandwidth when the average function
is activated, but the signal must be repetitive. The number of samples over which
the average is calculated can be selected by the user.
- Use the probe to connect Ch1 to the Probe Adjust output.
-Press AUTOSET.
- Connect the second probe to channel 2, but do not connect it to a signal!
- Press the CH1+CH2 key to add Ch1 and Ch2 together.
- Press the mV key of the CH2 AMPL keys so that the noise picked up by
the probe tip of the second probe appears on the CH1+CH2 trace.
- Press the AVERAGE key.
For maximum ease of use, the scope offers direct access to the important
average feature.
The text ’Average = 8’ appears in the bottom of the screen to indicate that the
function is active. The default value is 8. The indication changes into ’AVG’.
Observe that the noise on the trace is reduced.
- To change the Average constant, press the ACQUIRE key.
- Turn the TRACK control clockwise.
The Average factor increases when the TRACK control is turned clockwise.
Observe that this reduces noise on the trace even more.
-
Turn the TRACK control counterclockwise so that the Average factor is
8 again.
ST6481
TRACK
Average=2
AVG
Average=256
AVG