What must be done for the CGI to detect a gas other than its standard gases?

For the combustible gas indicator (CGI) to effectively detect gases other than its standard gases, it is essential to calibrate the instrument specifically for that gas. Calibration involves adjusting the device's sensor to recognize the unique properties and characteristics of the target gas. Different gases have different molecular weights, combustion properties, and sensor responses, so a tool not calibrated for a specific gas may yield inaccurate readings.

Calibrating the CGI ensures that the sensitivity and detection thresholds are appropriate for the target gas, allowing for reliable and accurate detection in various environments. This process typically requires using a known concentration of the target gas to fine-tune the equipment, ensuring it responds correctly to the specific gas in question.

The other options, while they might suggest different approaches, are not suitable for the task. Replacing the instrument entirely or attempting to configure it to a higher sensitivity without proper calibration could lead to unreliable detection or false readings. Similarly, adjusting the device to a "zero detect level" does not account for the specific characteristics of the gas, rendering the instrument ineffective for detection purposes.