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Sensor Settings and Calibration
AirLink 6940XP Operator’s Manual
Calibrating the Sensor (Manual Cal)
Each sensor can be manually or automatically calibrated, depending on the sensor’s calibration
method (see page 48 for setting the calibration method).
Sensors should ONLY be calibrated after completion of the zero process.
If the sensor calibration method is set to Auto Cal or the sensor being calibrated is an infrared
sensor, see page 40 to calibrate the sensor element.
NOTE:
LEL and CO
2
- LEL and CO
2
versions of the AirLink 6940XP can only be calibrated
using Auto Cal (see page 40).
HCl - It is recommended that the HCl version only be calibrated using Auto Cal, but
Manual Cal can be used if desired.
O
2
- If calibrating with 100% N
2
, you must use Manual Cal. To calibrate using Auto
Cal, a gas concentration between 10 and 18% O
2
is recommended.
Calibration Frequency
A calibration should be performed EVERY thirty (30) days. Days since the last calibration should
NEVER exceed ninety (90) days. RKI recommends that you calibrate your device regularly to
ensure proper functionality and a safe work environment.
Materials
• 0.5 LPM fixed flow regulator with knob and calibration tubing
WARNING: If calibrating with Cl
2
or HCl, a regulator must be dedicated for use with that gas
only. Do not use that dedicated regulator for any other gases, particularly H
2
S.
• calibration cup
• calibration cylinder or gas generator (For O
2
sensors, RKI recommends using 100% N
2
.
For all other sensors, RKI recommends using 50% of the full scale value of your detected
gas.)
NOTE:
Some detected gases use surrogate gases for calibration. Detected gases needing a
surrogate gas for calibration are listed below. If you are using a surrogate gas for
calibration, that surrogate gas concentration multiplied by the factor listed below should
equal about 50% of the detected gas’ full scale.
