Fresh Air Setup and Zero Calibration

To skip the ZERO procedure and move directly to the calibration span procedure, push the p button. If no button is pushed for 30 seconds, the device prompts user to perform a Span calibration before returning to the Normal Operation mode.

1.

Press and hold the p button in Normal Operation mode for three seconds.

2.

If calibration lockout option is selected, enter password.

ZERO screen displays.

• If calibration lockout option is NOT selected: ZERO screen displays.
3. With the device exposed to fresh air, press the q button to confirm the ZERO screen. A sensor refresh and Zero Calibration now occur. NOTE: Alternatively press the p button to execute a Fresh Air setup (FAS). See Fresh Air Setup (FAS)  for more details.

NOTE: After ZERO calibration completes, the device momentarily displays “ZERO PASS” or “ZERO ERR” along with the flag of any sensor that failed.

NOTE: During instrument zero calibration, the oxygen sensor is also span calibrated to 20.8% oxygen fresh air, adjusting the calibration curve as needed. During instrument span calibration, the O₂ sensor’s accuracy is checked against a known oxygen gas concentration without adjusting the calibration curve.