TSI Instruments SUREFLOW 8635-M, Operation And Service Manual

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Technical Section 25
Calibration
The calibration section explains how to calibrate the SureFlow pressure sensor, including
setting the proper elevation, and how to zero a flow station.
NOTE : The SureFlow pressure sensor is factory calibrated and normally does not need
to be adjusted. However, inaccurate readings may be detected if pressure
sensor is not installed correctly, or problems with the sensor exists. First check
that the sensor is installed correctly (usually only a problem on initial set up).
Second, go into DIAGNOSTICS menu, SENSOR STAT item. If NORMAL is
displayed, calibration can be adjusted. If an error code is displayed, eliminate
error code and then verify pressure sensor needs adjustment.
All pressure transducer based flow stations and 1 to 5 VDC linear flow stations
must be zeroed upon initial system setup. Linear 0 to 5 VDC flow stations do not
require a zero flow to be established.
Adjusting the SureFlow monitor calibration may be required to eliminate errors due to
convection currents, HVAC configuration, or equipment used to make the measurement.
TSI recommends always taking the comparison measurement in the exact same location
(i.e., under the door, middle of door, edge of door, etc.). A thermal air velocity meter is
needed to make the comparison measurement. Normally the velocity is checked at the
crack under the doorway, or the door is opened 1” to allow alignment of the air velocity
probe making the measurement. If the crack under the door is not large enough, use the
1” open door technique.
Calibrating pressure sensor - primary sensor or second sensor
Enter calibration menu (see Software Programming if not familiar with key stroke
procedure). Access code is turned on so enter proper 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 item in
Menu and Menu items 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.
Sensor zero
Slide open pressure sensor door and tape over 1/2 inch sensor orifice (see
Figure 6). Make sure pressure sensor orifice is taped over. Sensor is located
ab
out 3/4” into housing.
Select SENSOR ZERO item.
Press SELECT key. Sensor zero procedure, which takes 120 seconds, is
automatic.
Press
SELECT key to save the data.
Remove tape from sensor orifice and close pressure sensor door.