A: The price of the gas detector varies depending on the model, function, type of gas to be detected, brand and other factors. Generally speaking, the price of gas detectors ranges from a few hundred yuan to tens of thousands of yuan. Some high-end gas detectors may be more expensive, but these devices usually have higher accuracy and a wider range of applications. If you only need to detect a gas, you can choose a single gas detector, the price is relatively low. If you need to detect a variety of gases, you can choose a multi-gas detector, the price will be slightly higher.

In addition, depending on the occasion and environment of use, there are portable and fixed gas detectors to choose from. Portable gas detectors are generally light, easy to carry, and relatively low in price; while fixed gas detectors need to be installed and used in a fixed position, and the price is relatively high. When buying a gas detector, you need to choose according to your actual needs and budget. It is recommended to choose well-known brands and reliable quality products to ensure the accuracy and stability of the equipment, and also to obtain better after-sales service.

LEL refers to the percentage concentration of the lower explosive limit of combustible gas in air. It is widely used in the field of industrial safety to detect and measure combustible gases that may be present in the environment. This detector can quickly and accurately detect the presence of combustible gases in the air, thereby helping workers and related personnel to avoid possible dangers.

LEL detector usually adopts the principle of catalytic combustion. When combustible gas is detected, catalytic combustion generates heat, which changes the temperature. This change is converted into an electrical signal, and finally shows the gas concentration. This instrument usually has the characteristics of fast response, high accuracy and simple operation, and is widely used in industrial production sites, petrochemical enterprises, natural gas pipelines and other fields.

It should be noted that although the LEL detector can quickly and accurately detect combustible gas, some problems need to be paid attention to during use. For example, the instrument needs to be calibrated regularly to avoid errors; the influence of interfering gases needs to be avoided during the detection process; when combustible gases are found, timely measures need to be taken to avoid dangerous situations such as explosions. In short, the LEL gas detector is an important industrial safety device that can help companies and workers avoid possible dangers. It is necessary to understand its principles and characteristics during use, and pay attention to regular calibration and maintenance.

The four-in-one gas detector can usually detect four common gases, including oxygen, hydrogen sulfide, carbon monoxide and carbon dioxide. These gases are common toxic or harmful gases in many workplaces, so it is very important to detect them in real time.

1. Oxygen: Oxygen is a gas necessary to maintain human life, but when the oxygen content is too low, it may cause suffocation and death. When working in a closed or poorly ventilated environment, it is very important to monitor the oxygen concentration in real time.

2. Hydrogen sulfide: Hydrogen sulfide is a toxic gas, which is strongly irritating and corrosive. It is usually found in industrial wastewater, pulp mills, mining and petrochemical industries. Prolonged exposure to high levels of hydrogen sulfide can cause stinging eyes, breathing difficulties, and even death.

Carbon monoxide: Carbon monoxide is a colorless, odorless toxic gas, often due to incomplete combustion or poor ventilation. It can lead to lack of oxygen in the human body, and even lead to death in severe cases. The detection of carbon monoxide is particularly important in places involving high-temperature combustion such as gas, chemical, and steel.

4. Carbon dioxide: Although carbon dioxide itself is not toxic, when its concentration is too high, it will reduce the proportion of oxygen in the air and cause the human body to lack oxygen. In addition, high concentrations of carbon dioxide can also cause irritation to the respiratory system and skin.

Therefore, in a closed or poorly ventilated environment, real-time monitoring of carbon dioxide concentration is also necessary. The four-in-one gas detector is designed to ensure the safety of the staff. When the concentration of a certain gas in the environment exceeds the preset safety range, the instrument will immediately issue an alarm to remind the staff to evacuate as soon as possible or take appropriate ventilation measures. This real-time monitoring method helps to reduce the occurrence of industrial accidents and protect the lives of workers. Please note that different brands and models of four-in-one gas detectors may have different detection ranges, accuracy and response times. Before use, it is recommended to read the instrument instructions carefully to understand its specific functions and usage.

Carbon dioxide (CO2) classification guidelines:

Non-mandatory reference grading:

a )250 ~ 350ppm-usual outdoor air level.

B) 350 to 1,000ppm-typical in well-ventilated living spaces.

c) 1,000 to 2,000ppm-insufficient oxygen, drowsy enough to cause a complaint

d ) 2,000 to 5,000ppm-stagnant, old, stuffy air level. Headache, lethargy, accompanied by lack of concentration, decreased attention, rapid heartbeat and mild nausea.

e) > 5,000 ppm-exposure to which may result in severe hypoxia, permanent brain damage, coma and even death.

For the sensor, 400ppm is the concentration value of carbon dioxide in the fresh air environment. When the number of people gathered in the room or the concentration of carbon dioxide in the closed room will gradually increase, which will lead to hypoxia and other conditions, it is recommended to keep the closed room or the indoor with an increased number of people Ventilation, so as not to cause sultry, irritability, headache and other reactions!

The production of carbon monoxide in the underground garage mainly comes from the car engine. When the engine is running at idle speed, due to insufficient gasoline combustion, it will produce exhaust gas containing a large amount of carbon monoxide. The underground parking lot is a closed environment. Vehicles enter and exit frequently, and the exhaust gas is not easy to be discharged. It is easy to accumulate a large amount of carbon monoxide gas, which causes the parking lot to be filled with choking smell and damages people's health.

Carbon dioxide itself is non-toxic. Under normal circumstances, the carbon dioxide content in the air accounts for about 0.03 percent of the total volume of the atmosphere, which has no effect on the human body. However, when the concentration of carbon dioxide in the air is higher than 1%, people will feel stuffy, dizzy, and palpitations; when the concentration is higher than 5%, there will be symptoms of poisoning, such as headache, vomiting, confusion, etc.; when the concentration reaches 10%, People will lose consciousness, respiratory center paralysis, and even death. Therefore, the concentration of carbon dioxide in the air above a certain limit can make people suffocate.

Please note that although carbon dioxide itself is non-toxic, when its concentration is too high, it will have an adverse effect on human health due to the relative decrease in oxygen concentration. At the same time, high concentrations of carbon dioxide also have a negative impact on the environment. Therefore, in a closed and poorly ventilated environment, we should remain vigilant and take timely measures to reduce the concentration of carbon dioxide.