COX EC80 - Linearization Settings

Prole Programming
April 2019CXX-UM-03060-EN-01Page 26
c. With the Roshko/Strouhal values highlighted, right-click in the shaded area
and click Copy to place data onto the clipboard. Alternatively, with the data
highlighted, press Ctrl+C to copy the data to the clipboard.
2. Switch to or re-open the GUI and right-click IDX in the upper left corner of
the table.
3. Select Paste Grid to copy the raw data from the clipboard to the table.
Figure 15: Pasted table
Linearization
The Linearization process takes a raw, non-linear output from a turbine meter and
performs mathematical calculations to provide a linearized output. The EC80 Flow
Processor uses the Roshko/Strouhal method for correlating the meter’s volumetric
flow rate and reflects the sum of all rotors. In a single rotor application, the sum
Roshko and sum Strouhal equate to the correlation of a single rotor. In a dual rotor
application, the sum Roshko and sum Strouhal equate to the correlation of both
rotors, summed together.
The minimum number of IDX (X,Y) entries for the linearization table is 2. The
maximum number of IDX (X,Y) entries for the linearization table is 200. Fill out the
table according to instructions in “Table Data Entry” on page25.
In addition to the Linearization table itself, a number of additional fields on the
linearization tab can be changed. Although not typically modified from factory
settings, they perform additional advanced operations in the EC80 Flow Processor.
Field Function
Alpha
Corresponds to the coefficient of thermal expansion of the flow meter housing. This field
is factory configured for the thermal expansion of stainless steel. The thermal expansion
coefficient for stainless steel is 9.6 × 10
-4
or 0.0000096. Other expansion coefficients are
available from the factory.
Reference
Temp
The reference temperature, in degrees Fahrenheit, in which the calibration data was
obtained. Typical calibration reports state the reference temperature in which the data
was obtained, and should be the same as the temperature in which the Roshko/Strouhal
calibration data was obtained.
Rotor
Frequency
Cutoff
These fields limit the output of the flow processor to a minimum and maximum
frequency threshold. If rotor frequency decreases below the minimum flow rate or over
the maximum flow rate, the flow processor stops outputting a flow rate. The left column
corresponds to the rotor frequency of the A rotor (Upstream), and the right column is for
the B rotor (Downstream). In single rotor applications, only the left field is used.