OPERATION ST100A Series Flow Meter
48 Fluid Components International LLC
Figure 47 – Chart: Flow Output Over Time with Various Flow Damping Values
63.600
63.800
64.000
64.200
64.400
64.600
64.800
65.000
0 50 100 150 200 250 300
mA Output Converted to SFPS
Data Logger Samples (Every 250 mS or 240/Minute)
Damping = 0.25
Damping = 1.00
Damping = 3.00
Damping = 5.00
C01406-1-1
Flow Input Moving Average (Boxcar) Filter
Us
e the Flow Input Moving Average Filter field to smooth out the input flow signal using a moving average (boxcar) filter. The boxcar filter
averages the last
X
number of readings. A larger boxcar value does a better job of averaging at the expense of a slower response time.
The factory default boxcar value is 8 (readings). With readings occurring at 5 times a second, the factory boxcar setting is an average of
the last 1.6 seconds.
High boxcar values result in reduced flow response time. Make sure that alarm conditions are not affected when
using the moving average filter.
NAMUR Setup
German standard NAMUR NE43 defines a fault detection scheme that quickly indicates an instrument fault by driving its 4-20 mA output
current outside the normal operating range of the instrument, either to the low range or the high range.
Figure 48 – NAMUR Fault
Use the ST100A Series configuration software to enable/configure the NAMUR feature. The optional front panel HMI interface cannot
access NAMUR.
Click USB Connect on the home screen. Select the
Configuration
branch from the menu tree on the window's left side. Select the 4-20mA
User tab. Click on the NAMUR Enabled checkbox to enable the NAMUR feature.