1050 Hopper Ave, Santa Rosa, CA 95403 • Tel (800) AIRFLOW • www.airmonitor.com [email protected]
ELECTRA-flo G5 Transmitter Thermal Airflow & Temperature Measurement System 1015-3 - 07/18
22
Field Characterization
Field Characterization (K-factoring) of a flow element is the adjustment of the flow measurement
system to match a known reference measurement, (for our reference - most commonly airflow
traverse testing). Field Characterization is typically done when there is insufficient straight duct
run or another issue that creates questionable output from the installed measurement system.
A Field Characterization can be developed from one, two or
three references flow rates – more could be used, but are not
necessary. One traverse test is required for each flow rate. It is
recommended that a minimum of a low and a high flow rate are
used to determine a Field Characterization. If there is little to
no variance in the normal flow rate, it is feasible to use a Field
Characterization developed from a single flow rate test. If a high
and low flow rate test are performed and it is found that these
readings are substantially different, then a medium flow rate
should be considered to ensure a more accurate Field
Characterization. For any questions or concerns regarding Field
Characterization implementation, please contact Air Monitor.
Field Characterization:
On
enables the Field Characterization and the selection of
Calculate
or
Manual
. The
Calculate
selection will display the on-board calculator that will determine the
K-factor (device and reference data must be in-hand and ready to input).
Manual
displays the
Exponent and Gain value forms for inputting externally determined Exponent and Gain values.
Calculate
Number of Points is the number of flow reference points.
Each point is one reference flow rate (determined by traverse
testing or other) and the associated ELECTRA-flo system flow
rate. The traverse testing flow rate for these reference points
is performed before entering this screen and is written down
with the associated ELECTRA-flo point (flow rate). For most
applications, a minimum of two points (low and high flow
rates) are recommended for an accurate Field Characterization.
Three points may be required.
Electra Point 1 and Reference Point 1 will be the flow rates for the first test, Points 2 for the
second test and Points 3 for the third test. Best practice will be to go from the lowest to highest
flow rates when inputting this data. Once all data has been entered and the
ENT
button is pushed
for the final Reference Point, the Calculator will display the calculated gain and exponent values.
NOTE: Whenever a system is being retested in order to determine a new Field Characterization
(K-factor), the existing Field Characterization should be turned off prior to testing.
Field Characterization
ENT - Accept ESC - Leave UP/DN - Change
Calculate
On
Manual
Characterization Calculator
ENT - Accept ESC - Leave UP/DN - Change
Number of Points:
1
300.0
400.0
Electra Point 1:
Electra Point 2:
Electra Point 3:
Reference Point 1:
Reference Point 2:
Reference Point 3:
