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10.5) Calibration using the CO2 CALI function:
1. You will need a gas cylinder of pure Nitrogen (0 ppm CO2).
2. Temporarily cover the buzzer hole on the bottom left-hand corner of the SEU (Main unit) and
bottom right-hand corner on the RDU (remote display unit) with a small piece of masking tape to
minimize the alarm sound during calibration.
3. If calibration is to be performed installed, first inform building occupants that you will be
testing the CO2 alarm for several minutes.
ote: Please pump N2 (zero CO2) into the CO2 Sensor Entry (Item A in section 2) and wait about
3 minutes before calibration, then execute the “ZEro” calibration.
1. Hold the tubing from the Nitrogen (0ppm CO2) gas cylinder to the CO2 sensor opening (on
the top left-hand corner).
2. Open the gas regulator. Flow rate should be between 0.15-0.50 liters per minute.
3. Wait until the CO2 reading on the SEU settles consistently at or near 0ppm CO2.
4. Press the Mode button 5 times, the “CO2” and “CALI” icon will start flashing on the SEU.
5. Press Enter to view the calibration settings. The SEU screen will now display a flashing
“ZEro” and “CO2”.
6. Press Enter again to begin the calibration. “CALIBRATING” will begin flashing.
7. After approximately 3 minutes, the LCD will display either “PASS” or “FAIL”.
8. If the LCD reads “FAIL”, repeat the steps again. If it displays “PASS”, press Enter. The
display should now show 0ppm.
9. Remove the nitrogen cylinder.
10. Reset the unit by either pressing the reset bottom (bottom right-hand corner with a round
arrow) or power cycling the unit.
11. If your unit fails the “ZEro” calibration, please follow the procedure again before calling
support.
