Gas leak detector for home
With the centralized construction and development of residential buildings, high-rise buildings, intelligence and the popularization of piped gas, and the continuous improvement of social and economic levels, people are paying more and more attention to the safety of life and property. The state and local governments have formulated some Building fire protection design regulations and intelligent building regulations have promoted the application of gas leak detectors for home.
Types and components of domestic gas
There are three main types of civil gas currently used in my country: natural gas, liquefied petroleum gas, and artificial coal gas.
1.The main components of natural gas are: methane, ethane, nitrogen, carbon dioxide, hydrogen sulfide, and hydrogen. The worst natural gas contains more than 75% methane. Natural gas is less dense than air.
Due to the continuous discovery and exploitation of large gas fields in recent years, especially after the implementation of the “West-East Gas Pipeline” project, natural gas is gradually replacing liquefied petroleum gas and becoming an increasingly widely used civil gas due to its cost-effectiveness, safety and other advantages.
2.The main components of liquefied petroleum gas are: C3 and C4 linear hydrocarbons (endane and butane), containing a small amount of C2 and C5 (ethane and pentane). Liquefied petroleum gas is denser than air.
Liquefied petroleum gas was once the most widely used domestic gas and was used in canned form. However, due to its lower explosion limit and rising prices, it has gradually been replaced by natural gas transported by pipelines.
3.The main components of artificial gas are: H2, CO, CH and a small amount of olefins CmHn (abbreviation for linear hydrocarbons such as C2 and C3). In addition, it also contains a certain amount of N2, 02, and CO2. Artificial gas is less dense than air.
Gas leak detector for home selection
First, you should understand the types of gases that need to be detected on site. Currently, there are two types of gas sensors used by gas leak detectors for home: single selective gas sensors and universal sensors. Single selective gas sensors only respond to specific gases and have strong anti-interference capabilities. : Universal gas sensors can detect 1 to 3 types of gases, but their anti-interference ability is poor compared to single selective gas sensors. Therefore, it is recommended to choose a detector that uses a single selective gas sensor based on the type of gas. If the selected sensor does not match the actual gas to be detected, serious consequences of false alarms may occur. If you really cannot determine the type of gas, you can consider choosing a universal sensor after consulting the manufacturer. When detecting artificial gas, it is necessary to clarify the composition as much as possible, which is usually H2, CO, and inert gases, but in some areas a larger amount of methane is added. Methane has an adverse effect on the single selective sensor of artificial gas.
Gas leak detector for home Commonly used gas sensors are mainly divided into two types according to detection methods: catalytic combustion sensors and semiconductor sensors.
Semiconductor gas sensors work by detecting changes in gas content with gas sensors, and mainly use metal oxide ceramic gas sensor materials. With the research and development of new materials such as composite metal oxides and mixed metal oxides in recent years, the characteristics and application range of this gas sensor have been greatly improved.
Catalytic combustion sensors can be divided into direct contact combustion and catalytic contact combustion. Its working principle is: gas sensitive material in the state of power, flammable gas oxidation combustion or oxidation combustion under the action of catalyst, the heat generated to heat up the electric heating wire, so that its resistance value changes, so as to measure the gas concentration. This sensor can only measure combustible gases and is not sensitive to non-combustible gases. For example, sensors made of active catalysts Rh and Pd coated on Pt filament have broad spectrum characteristics and can measure various combustible gases. Contact combustion gas sensors are very stable at ambient temperatures and can detect most combustible gases at the lower explosive limit.
In comparison, the advantage of catalytic combustion sensors is high sensitivity, but the disadvantage is high power consumption and the need for preheating; the advantage of semiconductor sensors is low power consumption, but the disadvantage is low sensitivity.