Zero Calibration Procedure

1. Press the p button for five seconds in Normal Measurement page.

ZERO screen displays.

To skip the ZERO procedure and move directly to the span calibration procedure, push the p button. If no button is pushed for 30 seconds, the device prompts user to perform a SPAN calibration before device returns to the Normal Measurement page.

To perform ONLY a Fresh Air Setup at this time, press the ■ button. The device then performs a Fresh Air Setup as described in Turning ON and Fresh Air Setup. When the Fresh Air Setup is complete, the device returns to the normal Measure screen.

2. Press the q button to confirm the ZERO screen, i. e. to execute zero calibration.
○ The message "SENSOR REFRESH" displays, followed by the message "ZERO CALIBRATION".
○ The "REFRESH" message does not appear if a catalytic combustible sensor is not installed.
○ ZERO calibration starts.
○ A progress bar shows the user how much of the calibration has been completed.

During the first moments of a ZERO calibration, the combustible sensor reading may be replaced by a moving display of “PLEASE WAIT”. This is normal.

NOTE: After the ZERO calibration is completed the device displays either

• “ZERO CALIBRATION PASS”

or

• “ZERO CALIBRATION FAIL”.

NOTE: Only if the device passes the zero calibration the SPAN screen displays.