Malvern Instruments Spraytec, User Manual

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Time-based averaging is generally used to produce a . psh file containing
average results for rapidly repeating pulsed spray events such as observed
during fuel injector operation. Here the average is calculated either between
Group Trigger marks or over fixed, repeated time periods.
The Time-Based Average is configured using these options:
Average Between Trigger Marks – calculates a new size history
containing the averages calculated between group trigger marks. For this
the parameter
Grouping must be enabled on the Rapid Measurement
dialogue (see above).
Average Over Time Intervals – calculates a new size history containing
the averages calculated over a fixed, repeating time window. Use the time
interval selection box to specify the length of the time window.
.
Select the Average between trigger marks radio button. As the graphic
in the dialogue shows, this averages the data between successive triggers.
For a fuel spray the averages over a series of these periods should be flat.
.
Click OK then Next then Finish to complete the SOP setup.
Manual measurements
Manual measurement is like designing an SOP while actually making the
measurement, rather than designing the SOP first as a separate task. In a manual
measurement the measurement parameters are configured as part of the
measurement procedure, immediately before the sample is measured.
Why use manual measurement? The following are reasons to do so:
.
As a “temporary SOP” for trying out new settings.
.
When a new spray is being tested and the user is unsure about the parame-
ters to use.
Once settings are optimised the completed measurement is added to the list in the
Measurement file window. The SOP used can be saved and re-used by
right-clicking the record in this window and selecting
Extract SOP , then saving
it with a new name.
'
N o t e
. The default settings during a manual measurement are based on the last
set of parameters used.
C H A P T E R 5
S p r a y t e c
P a g e 5 . 2 9