The principle of carbon monoxide alarm

Carbon monoxide alarms can be divided into household carbon monoxide alarms and industrial carbon monoxide alarms according to the direction of use. In addition, they can be divided into wall-mounted / fixed carbon monoxide alarms and portable carbon monoxide alarms. Depending on your different requirements, you can choose different Instruments.

Carbon monoxide is a toxic gas, it is colorless and odorless, it is difficult for us to perceive with the five senses. Carbon monoxide is extremely harmful to the human body. Some rural households close their doors and windows and burn stoves for heating in winter. Natural gas, liquefied gas, coal gas, etc. are incompletely combusted, and a large amount of carbon monoxide is generated when the engine is turned on in a closed space. Most people are undetectable when they are poisoned by carbon monoxide. Many people have fallen into a deep coma when they were discovered, and some even died. At this time we need a carbon monoxide alarm. Carbon monoxide alarms are divided into household and industrial use. The main problem is to alarm when carbon monoxide is generated in the space. So what is the working principle of carbon monoxide alarm?

working principle

The carbon monoxide alarm uses a Carbon Monoxide Sensor to sense the concentration of carbon monoxide gas in the air and converts it into an electrical signal. 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 performance is Infrared Carbon Monoxide Detector, but it is more expensive and suitable for laboratory use. Civilian is generally semiconductor and electrochemical carbon monoxide alarm.

The semiconductor carbon monoxide alarm uses a semiconducting carbon monoxide sensor as the sensitive element. It requires that the sensitive element can respond quickly when the constant temperature is about 200 ℃. Therefore, it is necessary to increase the heating wire heating, so it is necessary to provide a relatively large current. When the temperature, humidity or even Large wind changes are very detrimental to its measurement, and it is also susceptible to cross-interference with other gases, such as alcohol, nitrogen oxides, hydrogen, alkanes, and other gases. It is easy to misreport, but it is cheap. The general service life can reach five years.

The electrochemical carbon monoxide alarm uses a zero-power electrochemical carbon monoxide sensor as a sensitive element. Most of them use the principle of fixed-potential electrolysis in the electrochemical method, and use the fixed-potential electrolysis method to carry out the redox electrochemical reaction, and detect the diffusion current to obtain carbon monoxide The concentration of the gas has a good linear measurement range and a high selectivity. It is also very resistant to cross-gas interference, and the price is relatively expensive. The electrochemical carbon monoxide sensor is a zero-power consumption type that does not require heating. It is very suitable for use with battery-powered detection circuits in conjunction with low-power detection circuits to make carbon monoxide concentration meters and portable carbon monoxide alarms. Long-term exposure of electrochemical carbon monoxide sensors to irritating solvents such as oxygen-free gas samples, alcohol, paint, etc. will affect their sensitivity and lifespan, or even fail. The use of electrochemical carbon monoxide sensors in the air is generally three years, there are also five years, the longer can reach more than eight years.