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Reference Manual
00809-0100-4444, Rev AC
Section 5: Advanced Configuration Functionality
January 2015
Advanced Configuration Functionality
default values. When using filter mode, perform an auto zero with no flow and a full sensor. Either
of the parameters (coil drive mode or signal processing) may still be changed individually.
Turning signal processing off or changing the coil drive frequency to 5 Hz will automatically
change the operating mode from filter mode to normal mode.
Signal processing control
DSP can be turned on or off. When on is selected, the 8732EM output is derived using a running
average of the individual flow inputs. DSP is a software algorithm that examines the quality of
the electrode signal against user-specified tolerances. This average is updated at the rate of 10
samples per second with a coil drive frequency of 5 Hz, and 75 samples per second with a coil
drive frequency of 37Hz. The three parameters that make up signal processing (number of
samples, percent limit, and time limit) are described below.
Number of samples
The number of samples sets the amount of time that inputs are collected and used to calculate
the average value. Each second is divided into tenths with the number of samples equaling the
number of increments used to calculate the average. This parameter can be configured for an
integer value between 0 and 125. The default value is 90 samples.
Percent rate
This parameter will set the tolerance band on either side of the running average, referring to
percent deviation from the average flow rate. Values within the limit are accepted while values
outside the limit are scrutinized to determine if they are a noise spike or an actual flow change.
This parameter can be configured for an integer value between 0 and 100 percent. The default
value is 2 percent.
Time limit
The time limit parameter forces the output and running average values to the new value of an
actual flow rate change that is outside the percent limit boundaries. It thereby limits response
time to flow changes to the time limit value rather than the length of the running average.
LOI menu path Detailed Setup, Sig Processing, SP Control
Traditional fast keys 1,4,3,1
Device dashboard 2,2,8,6,1
LOI menu path
Detailed Setup, Sig Processing, SP Control, Samples:
Traditional fast keys
1,4,3,1
Device dashboard
2,2,8,6,2
LOI menu path Detailed Setup, Sig Processing, SP Control, % Rate:
Traditional fast keys 1,4,3,1
Device dashboard
2,2,8,6,3
LOI menu path
Detailed Setup, Sig Processing, SP Control, Time Limit:
Traditional fast keys
1,4,3,1
Device dashboard
2,2,8,6,4