Technical Section
59
Calibrating Pressure Sensor
Enter calibration menu (see
if not familiar with keystroke procedure).
Access code is turned on so enter access code. All menu items described below are found in
CALIBRATION
menu.
Elevation
The
ELEVATION
item eliminates pressure sensor error due to elevation of building.
(See
ELEVATION
section for further information).
Enter the
ELEVATION
menu item. Scroll through the elevation list and select the one
closest to the building’s elevation.
Press the
SELECT
key to save the data and exit back to the calibration menu.
Figure 8: Pressure Sensor Door Slid Open
Sensor span
WARNING
: The span can only be adjusted in the same pressure direction.
Adjusting span cannot cross zero pressure. Example: If unit
di0.0001 and actual pressure is -0.0001, do
not
make any
adjustments. Manually change the air balance, close or open
dampers, or open door slightly to get both unit and actual pressure
to read in same direction (both read positive or negative). This
problem can only occur at very low pressures so slightly changing
the balance should eliminate the problem.
Perform a smoke test to determine pressure direction.
Select
SENSOR SPAN
item.
Position thermal air velocity meter in door opening to obtain velocity reading. Press
S
/
T
keys until pressure direction (±) and sensor span match thermal air velocity meter
and smoke test.
Press
SELECT
key to save sensor span.
Exit menu, calibration is complete.
