In terms of safety, what should be monitored amidst combustion in gas appliances?

Monitoring O2 levels during combustion in gas appliances is crucial for several reasons related to safety and efficiency. Proper combustion of natural gas or propane requires a specific amount of oxygen. If oxygen levels are too low, it can lead to incomplete combustion, creating hazardous byproducts such as carbon monoxide (CO), which is a colorless and odorless gas that can be fatal in high concentrations.

By continuously monitoring O2 levels, technicians can ensure that the appliance is operating within the safe limits and is conducting efficient combustion. This helps in reducing the production of harmful emissions and enhances the overall safety of gas appliances in residential and commercial settings.

Other aspects like sound levels, light emissions, and physical vibration may provide some degree of information about the operation of gas appliances, but they are not directly linked to the combustion process or safety in the same vital way as oxygen levels are. They do not offer insight into the efficiency of combustion or the potential risks associated with improper gas burning.