MeshGuard LEL IR & CO2 IR User’s Guide
24
5.9.3.
Zero Calibration
This operation sets the zero point of the sensor calibration curve for clean air. It should be
performed before other calibrations.
IMPORTANT!
Even though most toxic gas sensors can be zeroed in fresh air, the CO
2
sensor should
not
be
zeroed in fresh air. CO
2
gas is normally present in ambient air, so zeroing the CO
2
sensor in
ambient air will not allow for a true zero to be set. The CO
2
sensor should be zeroed in 99.9% pure
zero air.
Note:
If you use a zero air or other gas cylinder, you must use the MeshGuard Calibration Adapter.
A calibration adapter is not necessary for calibrating the MeshGuard LEL IR in clean fresh air.
When “CAL” and “go” are displayed in alternation, and “ZERO” is shown, the instrument is ready to
perform a zero calibration.
Press [Y/+]. The LCD displays “go.”
The display counts down from 60 to 0.
Calibration adapter
connected to
calibration gas cylinder
