Background

The main source of carbon monoxide in underground garages is the car engine. When the engine runs at idle speed, exhaust gas containing a large amount of CO will be produced due to insufficient combustion of gasoline. The underground parking lot is a closed environment, and vehicles come in and out frequently. The exhaust gas emitted is also not easy to discharge. It is easy to accumulate a large amount of CO gas. Carbon monoxide gas can cause a choking odor in the parking lot, which is harmful to people's health. Therefore, underground garages and parking lots should be equipped with air supply and exhaust systems to replace them with fresh air. The CO content of the underground garage should be lower than 25ppm in the long term and not higher than 37.5ppm in the short term. It can be monitored with a carbon monoxide alarm.

carbon monoxide alarm

Garage carbon monoxide detectors convert the concentration of carbon monoxide gas in the air into electrical signals through carbon monoxide sensors. The magnitude of the electrical signal is related to the concentration of carbon monoxide. Carbon monoxide alarms are classified according to the sensors used, generally divided into semiconductor carbon monoxide alarms, electrochemical carbon monoxide alarms, infrared carbon monoxide detectors, etc. In terms of measurement sensitivity, accuracy, stability, and resistance to cross-gas interference. The best performance is the infrared carbon monoxide detector. However, infrared carbon monoxide detectors are more expensive and suitable for laboratory use. Civilian carbon monoxide alarms are generally semiconductor and electrochemical.

Semiconductor carbon monoxide alarms use semiconductor carbon monoxide sensors as sensitive components. It is required that the sensitive element can respond quickly when the constant temperature is around 200 °C. Therefore, it is necessary to add heating wire heating, so a relatively large current must be provided. When the temperature, humidity and even wind change greatly, it is not good for its accurate measurement. There is also easy cross-interference of other gases.