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Operators Manual
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Statistics Example
Measurement: Quantify the performance of a number of dc outputs, making 10
measurements each time to evaluate the average and noise of the output.
Solution: In Trigger Setup, set the Triggers/Arm (Count) to 10. In DCV, push
to enable Statistics and then (Statistics). Push to put the
Product into the Idle triggering mode. Each push of gives new 10 readings
and stops. The average of 10 readings is displayed, and the standard deviation is
representative of the noise in the output signal.
(Chart + Statistics): When pushed, Statistics display along with either a
plot of the Trend or Histogram. Trend provides a visual trending of
measurements over time, where the vertical axis is the amplitude of the signal
and the horizontal axis is time. Histogram provides a graphical representation of
the distribution of a series of measurements. Measurements are grouped in bins
as shown with vertical bars. The vertical axis indicates the relative number of
readings for a range of values as a percentage. The sum of the vertical bars
equals 100 %. In Chart + Statistic view, about one-third of the Product’s display is
used for the chart.
(Chart + Statistics) menu is comprised of:
(Std Dev) where Normal displays the standard deviation of the data
record in the measurement units, and PPM displays it as parts per million.
(Plot) selects either the Trend or Histogram plots.
If Trend is selected,
(Mode) selects which part of the data record is displayed. All shows the
measurement points from the beginning of the record. The left side of the
horizontal axis in this case starts from 0. Recent shows the most recent readings
at the time of the button push, where the left side of the horizontal axis is the total
number of readings minus 101, effectively showing the last 100 readings at the
time of the button push. The right side shows the total number of measurements
or the time scale of the record in both cases. See the screens below.
Under Trend Setup:
(Auto) gives automatic scaling of the vertical axis such that all data in the
record is displayed with optimum vertical scale.
(Manual) allows user control of the vertical scale (maximum and
minimum).
(Auto Once) sets the vertical scale appropriately for the data record
captured so far but does not continue to rescale the chart as more data is added
(as Auto would do).
(X-axis) allows selection of the horizontal axis, as either the number of
readings, or time. To use Time, first enable Timestamps in the Memory Setup
menu.
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