Calibrate CO2 and LEL infrared sensors

Blackline’s carbon dioxide (CO₂) infrared and LEL infrared digital sensors perform calibrations independently of the Blackline detector. The span gas values for the calibration are configured in the Blackline Live portal, so special care must be taken to ensure the calibration gas used for the device calibration matches the portal configuration.

The default for CO2 calibration gas is 5000ppm. The default for LEL calibration gas is 2.5% CH4 (50% LEL).

If you change the defaults, ensure the configuration values in the Blackline Live portal match the gas values used for the calibration.

These two sensors accept a wide range of sensitivity. If the incorrect calibration gas is used, the sensor will likely pass the calibration anyway. The sensor will not be accurate during normal operation and user safety will be in jeopardy.

Other considerations:

• If 0 gas is used for the calibration, the sensor will likely output a gas reading after the calibration. Depending on configuration, the sensor may go into alarm right away.
• If the calibration gas used is greater in concentration than the configured calibration gas, the sensor will read low when real gas is encountered in the field. This is a dangerous unsafe situation.