K-O2 Oxygen Sensor
5/20/2022
Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
Page 10
www.kele.com
5.3 Z
ERO
C
ALIBRATION
P
ROCEDURE
For maximum accuracy below 18%, the Zero calibration procedure must be done before the Span calibration.
The progress and status of the calibration process is indicated by the color and flash-state of the front cover status
LED (see Table 10).
Apply the nitrogen (zero) calibration gas to the sensor using the included calibration cap. Ensure that gas is flowing
to the sensor, then press and hold the ’ZERO’ button (see Figure 8) for 3 seconds until the front cover LED starts
blinking YELLOW, indicating that gas sampling is in progress.
1.
Ensure that the calibration adapter remains correctly seated and calibration gas continues to flow for the
2 minute sampling period.
2.
At the end of the sampling period, the sensor’s status LED blinks GREEN if the sampling was successful or
RED if not.
3A. If successful (blinking GREEN):
The gas sampling completed successfully. Turn off the calibration gas flow, remove the calibration cap
then
press and hold
the ‘ZERO’ calibration button until the LED blinks GREEN/YELLOW indicating that the
calibration gas has been removed, the calibration has been applied and the unit is in standby for two
minutes while the sensor re-equilibrates to the ambient atmosphere before normal operation resumes.
The calibration is complete when the status LED returns to steady GREEN.
OR
3B. If NOT successful (blinking RED):
The most likely cause of zero calibration sampling failure is insufficient gas flow or leaks around the
calibration adapter failing to completely immerse the sensor in nitrogen. Verify that calibration gas is still
flowing at the required rate (pressure gauge reads 10 psi) and the calibration adapter is properly
positioned.
The calibration sampling can be re-started
while the LED is blinking RED by again
pressing and holding
the ‘ZERO’ button until the LED blinks YELLOW, then return to step 1 above.
To exit the zero-calibration routine preserving the original calibration:
turn off the calibration gas flow
and remove the calibration adapter, then
press and quickly release
the ‘ZERO’ button. The status LED will
blink RED/YELLOW indicating that the calibration gas has been removed, the original calibration has been
kept and the unit is in standby for two minutes while the sensor re-equilibrates to the ambient
atmosphere before normal operation resumes. The original calibration is completely restored when the
status LED returns to steady GREEN.