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June 2012
Peak/Average Measurement
There are two types of measurement mode that can be selected for the digital
display- Average or Peak.
In average measurement mode, the measured signal is averaged over a
period set by the user and will give a useful average (mean) value for steady
(CW) sources or pulse periods which are less than the user-set average time
period.
In peak measurement mode, the user sets a peak hold period and the display
indicates the maximum value that was reached in each period. Peak mode
will capture and display even very fast or short-duration peaks depending on
the type of head connected.
To switch between peak and average measurement in the digital display
mode, press menu, scroll to Measure Mode using the up arrow (8) or down
arrow (2) buttons, press
, scroll down the list to select Average or Peak
and press
.
The selected mode is shown as ‘Av’ or ‘Pk’ on the display, see diagram 2.
In waveform display mode, the actual instantaneous level is displayed and
there is no option to set peak or average mode.
Setting Average and Peak Hold Periods
For more accurate mean measurements a longer average period is
recommended. A short average period will result in a less accurate value but
with a faster response time. To set the Average Period, press Menu and
scroll to Measurement Mode. Select Average Period. The current Average
Period is displayed. Use the Up/Down arrow buttons to choose the desired
average period over the range 0.25
– 10 seconds.
In Peak Measurement mode, the user can select the time period over which
the peak is measured. For example, if the peak hold period is set to 1 second,
the display will show the maximum value that is recorded in every 1 second
period. To set the Peak Hold Period, press Menu and scroll to Measurement
Mode, press
. Select Peak Hold Period and press
. The current setting
is displayed. Use the Up/Down arrow buttons to select the desired Peak Hold
Period in the range 0.25
– 10 seconds.
Trend Bargraph
There is a fast-responding trend bargraph under the numerical value which is
useful for laser tuning or alignment purposes. The bargraph always responds
instantaneously and is not affected by averaging or peak hold functions.
