Indoor air quality test instruments are commonly used to monitor airborne pollutants and harmful substances to help ensure the safety and comfort of workers. Handheld combustible gas detectors identify natural gas leaks and analyze emissions from pipes, equipment, and tanks. Gas analyzers detect dangerous levels of invisible gases, such as carbon monoxide or carbon dioxide, that may be present in indoor air. Indoor air quality screening kits and particle counters help achieve clean indoor air by checking for specific pollutants such as mould, dust mites, or other allergens.