Fluke FLK-8845A/SU [54/93] Using the histogram function

8845A/8846A

Users Manual

3-14

As shown in Figure 3-1, the display will start plotting the readings across the plot area,

and the maximum, minimum, and elapsed time are displayed.

STOP

F1 F2 F3 F4 F5

caw057.eps

Figure 3-1. TrendPlot Display

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

standard deviation. The two bars on either side of the center two bars represent the

number of readings that fall within the 2

standard deviation. The next two represent the

standard deviation and so on to the 5

standard deviation.

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.

F1 F2 F3 F4 F5

caw056.eps

Figure 3-2. Histogram Display

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

connecting the signal to the Meter’s input.

2. With the Meter taking measurements, press J.

3. Press HISTOGRAM to start the session.