1. Industrial safety: In industrial environment, portable gas detector can be used to detect the concentration of harmful gases such as combustible gas and toxic gas to ensure the safety of workers.

2. Fire safety: In fire rescue, portable gas detector can be used to detect the concentration of combustible gas at the scene of fire to determine the nature and degree of fire and provide safety guarantee for firefighters.

3. Environmental monitoring: In environmental monitoring, portable gas detector can be used to detect the concentration of pollutants in the air, such as PM2.5 and formaldehyde, so as to evaluate the environmental quality.

4. Health care: In the field of health care, portable gas detectors can be used to detect the air quality in wards, operating rooms and other places to ensure the health and safety of patients and medical staff.

5. Scientific research: In scientific research, portable gas detector can be used to detect the concentration of various gases to study the properties and functions of gases.