Sure-Aire™ Flow Monitoring System
7
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Recalibration Procedure
The electronics are calibrated per order at the factory. Under certain circumstances, there may be a discrepancy
of calibration once installed on site. The following procedure is used to re-calibrate the pressure trandsucer within
the electronics. In the event an error occurs trying to re-calibrate, the tranducer parameters can be re-set to factory
settings using “Load Factory Settings” within the setup menu.
Equipment
Digital multimeter.
Vacuum pressure device with gauge (only needed if calibrating upper range).
200-900 ohm resistor (only needed if calibrating using 4-20 mA).
Procedure
1. Remove power to the electronics.
2. Remove any wires connected on the analog outputs.
3. Remove tubing from Sure-Aire™ electronics box, box uses push-to connect fittings.
4. Connect multimeter to analog points on terminal strip. If calibrating using 4-20 mA, a series load resistor
between 200 and 900 ohms is required.
5. Set multimeter to the correct measurement units, VDC or mA.
6. Apply power to the Sure-Aire™ electronics.
7. Press the “Setup“ button on the LCD panel.
8. Verify the analog signal is setup for your measurement and that the signal is linear to Differential Pressure.
9. Go to the “Trans Min/Trans Max” screen. Record the values for each. It is correct that the trans min value is
higher than the trans max value.
10. Press “Enter / Edit”.
11. With all tubing removed, adjust the trans min value up / down until the multimeter reads either 2 VDC or 4 mA.
12. Press “Next” if only calibrating low value. Press “Enter” to complete.
13. To calibrate upper range, apply the pressure device to the high port and pull vacuum to maximum pressure on
Sure-Aire™ label.
14. Adjust the trans mix value up/down until the multimeter reads either 10 VDC or 20 mA.
15. Press “Enter” to store the new value.
16. Press “Exit” to return to the main screen.
17. Optional: go to “Save Customer Defaults” and save for future resetting to the changes.
