Using The Histogram Function; Controlling Trigger Functions - Tektronix DMM4040 User Manual

DMM4040/4050
Users Manual
To stop the TrendPlot session, press B or the STOP soft key.
To start the TrendPlot session over, press the STOP soft key followed by the
RESTART soft key.

Using the Histogram Function

The Histogram function provides a graphical representation of the standard deviation of a
series of measurements. The right two-thirds of the Meter's display is used as a bar graph
chart. The vertical axis is a relative measure of the number of readings while 10 vertical
bars represent the standard deviation across the horizontal axis. The two center bars
indicates the number of readings that fall on either side of the average reading within the
st
1 standard deviation. The two bars on either side of the center two bars represent the
number of readings that fall within the 2
rd
3 standard deviation and so on to the 5
The histogram function is helpful in looking at the standard distribution of the UUT.
While observing the bar graph display (see Figure 3-2), adjust the UUT variable control
to peak the center two bars of the histogram.
In addition to the bar graph, the left third of the display also displays the number of
samples, the average, and standard deviation values.
To start a histogram session:
1. Set up the Meter for the desired measurement by selecting the function, and
2. With the Meter taking measurements, press J.
3. Press HISTOGRAM to start the session.
The display will start adjusting the bar graph as the number of readings accumulates. The
mean and standard deviation values also change in accordance with the collected
readings.
To start the histogram session over, press the STOP soft key followed by the
RESTART soft key.
To stop the histogram session, press B or the STOP soft key.

Controlling Trigger Functions

The Meter's trigger functions allows you to select a measurement trigger source, set the
number of measurements (samples) per trigger, and set the delay time between receiving
the trigger and the start of a measurement. In addition, the trigger function provides a
"measurement complete" signal on the trigger port on the rear panel. See item 5 in
Table 3-3. Triggering the Meter remotely through one of its communication interfaces is
3-16
F1
Figure 3-2. Histogram Display
connecting the signal to the Meter's input.
nd
standard deviation. The next two represent the
th
standard deviation.
F2 F3 F4 F5
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