Automation, Inc.
™
26
TM_GF-
A
2
1
00_2200_R1A
GF-A2100
AND
GF-A2200 A
IRFLOW
M
EASUREMENT
S
TATION
Air Flow Measurement, PID Control and Alarm Solution - Analog Output
GreenTrol Automation, Inc.
•
156 Holly View Lane Loris, SC 29569
•
Toll Free: 877-4GN-TROL (877.446.8765)
•
Internet:
GreenTrol.com
TRANSMITTER CALIBRATION
The GF-A2100/GF-A2200 uses high quality industrial grade components and is designed for years of trouble-free oper-
ation. Periodic recalibration of the transmitter is not required or recommended. Transmitter field calibration verifiers are
available for purchase for installations requiring periodic validation. Contact factory for additional information.
FIELD ADJUSTMENTS
The GF-A2100/GF-A2200 is factory calibrated and should not require adjustment (other than the installed altitude) when
sensor probes are installed in accordance with factory application installation guidelines. Some installations however,
may not meet placement guidelines, or commissioning requirements may necessitate field adjustment. Field adjustment
may improve the “installed accuracy” of the GF-A2100/GF-A2200 when determining volumetric flow rates.
Altitude Correction Adjustment
The Altitude Correction Adjustment allows for correction of airflow readings at the installed site altitude and more pre-
cise readings regardless on installed altitude. Refer to the Setup Menu Options, “*ALT=” menu item in Figure 15 to
set this vale to the installation altitude.
Adjusting the Low Limit Cutoff
The low limit cutoff forces the analog airflow output signal to zero whenever the measured airflow rate falls below the
specified Low Limit value. This feature is useful on outside air intakes that often indicate false airflow rates, induced by
transient wind gusts or when the intake damper is closed and there is no net flow across the damper. Readings of 100
FPM or more are not uncommon on many outside air intake applications when the intake damper is closed as a result
of air movement in the intake plenum and not a malfunction in the airflow measuring device. Setting the low limit to a
value significantly below the control setpoint and higher than the threshold flow for false wind readings simplifies con-
trol and interpretation of the airflow rate signal on many applications. To set the low limit cutoff, enter Setup menu and
set “*LL={desired value}” as shown in Figure 15.
Adjusting the Digital Output Filter
The digital output filter is useful for dampening signal fluctuations resulting from transient wind gusts on outdoor air
intakes or excessive turbulence generated from duct disturbances. The digital output filter range can be set between 0
(OFF) and 99%. Increasing the filter percentage limits the allowable change of the output signal. To change the amount
of digital filtering, enter the Setup menu and set “*FILTER={desired value}” as shown in Figure 15.
Field Calibration Wizard - Adjustment of Factory Calibration
Overview of the Field Calibration Wizard
The simple to use Field Calibration Wizard provides a one or two point menu driven field adjustment to factory calibra-
tion of the airflow signal. The Field Calibration Wizard is most useful on larger duct sizes where the sensor density is
lower, and the installed accuracy uncertainty is greater. The Field Calibration Wizard allows engineers, contractors and
owners to use stable and linear flow meters at a more affordable cost, where field adjustment is necessary or accept-
able. This feature is especially valuable on outside air intake applications in close-coupled installations.
When evaluating the GF-A2100/GF-A2200 using other reference airflow devices, ensure that the reference measure-
ment device and the technique used to determine the airflow rate in the field are suitable for such measurement. Select
a location that is suitable for the reference measurement device, recognizing that this may not be the same location
where the GF-A2100/GF-A2200 airflow station is installed. The inherent accuracy of the field reference measurement
will not be better than ±5% of reading and measurement uncertainty can often exceed ±10%. Do not adjust the output
of the GF-A2100/GF-A2200 if the difference between the transmitter and the field reference measurement is less than
10%. The following paragraphs detail use of the Field Calibration Wizard.
Fluctuations of airflow output signal are normal. Laboratory research indicates that dampening true fluctuations will result in poor
control and a larger dead-band of operation. Therefore, the use of the dampening filters in control devices is not recommended.