Carbon monoxide detector for home: details about leak detection devices

Carbon monoxide poisoning, unfortunately, is not such a rare accident that accompanies the illiterate operation of a solid fuel or gas boiler, fireplace, gas stove, or water heater. Spread of a toxic substance can also occur if broken equipment is used. A frightening prospect, you will agree.

A miniature device - a carbon monoxide detector for the home - will promptly warn the owners and eliminate negative consequences. It reliably detects the appearance of harmful substances in the air. Here you will learn how to choose it correctly, where to install it, how to monitor and respond to the device’s readings.

In the article we presented, the principle of operation is thoroughly analyzed and the types of sensors that ensure the safety of household members are given. The installation process is carefully described and valuable recommendations are given. To optimize perception, the material is supplemented with visual illustrations and video tips.

Carbon monoxide and its negative effects

Carbon monoxide, or CO as it is also called, is a product of the oxidation reaction of substances at high temperatures; in other words, carbon monoxide is formed during the combustion process. CO is always released in small quantities when food is cooked.

However, exceeding the permissible gas content in a room is fraught with serious damage to health, and can sometimes lead to death.

Carbon monoxide kills thousands of people every year simply because people fail to perceive the threat before symptoms occur. This often happens when it is too late to do anything.

Only special devices can detect the substance in the air, because the gas has neither odor nor color. In addition, it has a toxic effect on the body upon inhalation.

When carbon monoxide enters the lungs, it combines with hemoglobin to form carboxyhemoglobin. The substance interferes with the process of saturating blood cells with oxygen and causes hypoxia of body tissues.

To determine the presence of gas in the air, sensors are used, the scope of which is demonstrated by a photo selection:

As a result, the functioning of internal organs is disrupted, primarily the nervous system and brain suffer.

The severity of poisoning depends on the amount of carbon monoxide in the room:

1. With a CO content of 0.08%, the first symptoms of poisoning are mild malaise and drowsiness.
2. Then a headache and dizziness begin, and a cough appears.
3. In especially severe cases, damage to the mucous membranes of the nasopharynx, paleness of the skin and disruption of the heart are observed.
4. When the level increases to 0.32%, loss of consciousness, coma and paralysis occur due to oxygen starvation, and death occurs within half an hour.
5. If the gas level rises to 1.2%, the person dies within 3 minutes.

Leakage of the substance occurs mainly in private buildings due to faulty ventilation and chimney channels. In addition, gas appliances, boilers and other equipment often fail, and as a result, the CO level in the room rises.

An example is the most common case when poisoning occurs during sleep, because intoxication cannot be identified by smell.

Gas used in everyday life and its combustion products cannot be detected without a device, because they have no color or smell

For rescue, the victim must be immediately taken out into fresh air. It is also recommended to perform deep ventilation of the lungs using an oxygen mask.

Often the cause of a leak is poor draft over an open fire source, an improperly designed smoke exhaust system, or a malfunction of the gas stove. When living in the private sector, you need to follow safety precautions when using heating elements.

When igniting solid fuel boilers and stoves, do not close the damper ahead of time. In addition, the layout of some private houses also includes an attached garage, which can lead to excessive release of fumes and its entry into the living part of the premises. This is especially dangerous if the extension is poorly ventilated.

Emergency protection equipment

To eliminate false fears about a possible leak, it is worth installing a carbon monoxide identification system. The device will report on the state of air in the room and notify residents if toxic fumes exceed the norm.

The detector does a good job of identifying not only CO, but will also notify residents of a domestic gas leak. If a fire has already started, the sensor will not recognize it, but in terms of preventive measures, it is indispensable.

The detector can be located on any vertical surface. The display constantly reports the status of the device and the level of toxic gases in the air

The device will instantly respond to changes in the chemical composition of the air.According to installation rules, it is best not to install sensors in close proximity to open fire sources, but simply in the same room with heating equipment.

If the room is equipped with several heating units, it is necessary to organize a system of an equal number of detectors.

A wide range of manufacturers provide consumers with different carbon monoxide detection devices every year. Despite the fact that the form factor of each device is determined individually, the design principle is almost always the same.

The operating principle and specifics of the sensor device are introduced in the photo:

A distinctive feature of the gas detection device is that the detector is not designed to identify smoke. This means that in addition to the CO sensor, it is recommended to install a fire safety system separately.

The sensor's response to exceeding permissible parameters in the air is a sound signal, which indicates a toxic gas leak. Before use, you must read the instructions and test the device in an accessible, non-hazardous way, becausePeople often confuse a CO leak signal with an audible low battery indicator.

There are portable devices that have already become an integral attribute of carbon safety in many countries, including Russia

Also, almost all devices have a function self-fault notifications. The tone and interval of each sound is different. If the detector signals a low battery, the sound in most cases has a clear, abrupt character and occurs once per minute.

It is recommended to promptly replace the battery, since the health and life of household members depends on the proper functioning of the device. Mostly, replacement should be made no more than 2 times a year.

A constant squeak from the detector may indicate an increase in the level of toxins in the air, or a breakdown of the equipment. In any case, you must immediately call emergency services.

If symptoms of poisoning are detected, you must immediately open all windows and, after leaving the room, wait for the team outside.

Technicians will check oxygen levels and identify leaks. If it turns out that the signal is false, the detector will need to be replaced with a new one.

Some carbon and natural monoxide detectors for the home are able to recognize even fairly safe substances that have a high degree of evaporation. This primarily applies to alcohol and all alcohol-containing liquids.

When using alcohol-based cleaning products, you need to better ventilate the room to avoid false alarms of the security system.

If there is a high concentration of vapors, the system may sound an alarm, but do not worry and immediately call the emergency service.Also, the detector may be triggered during the preparation of certain products, mainly those that have undergone the fermentation process.

This is mainly typical when the appliance is located close to the hob. If this happens quite often, you should install the sensor away from the cooking area.

Types of air analyzers and their advantages

Increasingly, people are resorting to using certain models of household CO sensors. The most popular options include 3 main types of devices:

• Semiconductor based detectors.
• Infrared sensors.
• Devices with electrochemical detection method.

In order to understand which device will flawlessly cope with the task of detecting dangerous gas and is suitable for the means and installation methods, you need to understand their specifics.

#1: Semiconductor gas detectors

Equipment of the first type is fundamentally different from the other two, because works on the principle of chemical processes of interaction between atoms of substances. In most cases, dioxides are used as the active substance, namely carbon, tin and ruthenium.

Semiconductor alarms are connected directly to the power supply network. Basically, you will hardly find similar battery-powered equipment on the market.

The method for determining toxins is to increase the conductivity of the affected air. As a result, contact between the detector components occurs. Then a mechanism is activated, signaling the presence of carbon monoxide. The reaction occurs between atoms.

SnO₂ (tin dioxide), or RuO₂ (ruthenium dioxide).To carry out the diffusion of atoms, it is necessary that the chemical elements be subject to heating at a temperature of at least 250 degrees Celsius.

Conductivity of clean air in a SnO-based device₂ and RuO₂ is extremely small, so the device is active only in the presence of CO.

When heated, electrons begin to be released from oxygen atoms under the influence of carbon monoxide. This process increases the conductivity of the detector capsule, which causes the sensor contacts to close, and as a result, an alarm is triggered.

Voltage primarily depends on the amount of CO monoxide in the air. When the permissible level is exceeded, the voltage increases, so there are practically no false positives recorded with the semiconductor detector.

The only exceptions are cases when the device is located too close to the fireplace hearth, stove firebox, geyser burner. This is true for all types of equipment. Therefore, it is recommended to install at some distance from the heating panels.

The design of a semiconductor sensor begins with a solid base. It is made of a polymer material related to saturated polyesters. The body itself is made of stainless steel. The front part plays the role of an inlet where air contaminated with toxins penetrates.

To prevent the penetration of combustion-related substances, the detector body contains a carbon layer. The latter performs the function of an absorbent. There is also a double layer of stainless mesh to protect against physical contaminants such as dust.

The sensitive element is located deep in the housing, under a layer of carbon filter.The voltage is connected directly to the metal terminals on the other side of the capsule

In most cases, semiconductor sensors have 3 contacts for connecting electricity. This is due to the fact that the design of the device contains 2 electrical circuits - for the heater and for the metal dioxide element.

This type of sensor is characterized by a high degree of wear resistance and a long service life. In addition, due to its small dimensions, it consumes extremely little electricity, but in terms of CO detection, the device is on the list of the most efficient.

The video presents the device of a semiconductor detector, an example of the sensor’s performance:

#2: Infrared variety of analyzers

A completely different operating principle is observed with infrared sensors. Here, air acts as an analyzer, which is then tested for the presence of CO using infrared irradiation.

The main criterion that determines the level of carbon monoxide is the wave spectrum of the IR element, which absorbs carbon monoxide toxin molecules. Because light is much more sensitive to external influences, these types of sensors are successful in identifying a variety of pollutants, including methane.

The IR sensor is programmed to a certain CO level, which is considered a reference value. If the set limit is exceeded, an alarm is triggered.

The role of the sensitive element is performed by an LED or an incandescent filament. Such IR gas leak sensors are called non-dispersive. The gas level is analyzed thanks to special light filters that are configured to perceive only a specific spectrum.

Sensors of this type are not often used in our country. Due to the increased price, they are installed mainly in large institutions

If the chemical composition of the air changes, the element reacts, the light wave changes, and the detector detects an excess of the permissible level of the desired gas. In this case, the level of spectrum change is directly proportional to the percentage of the chemical in the air.

Detectors of this type are often used not only in everyday life, but also as special devices for detecting toxic leaks. The selectivity of the equipment allows it to successfully scan the air for the presence of heavy gases such as ammonia and chlorine.

As for the design, the device is powered by connecting to a 220 V network. However, most options for household devices include the ability to operate on batteries.

To indicate gas contamination, the device is equipped with a backlit display and an audible alarm system. If a gas leak is detected, the sensor will immediately produce a clear, abrupt squeak, and the device monitor will begin to blink.

#3: Catalytic Gas Detectors

The main difference between electrochemical sensors is the rather low level of energy consumption. This is due primarily to the fact that the design of the device does not have a heating element, and the role of a sensitive substance is played by a liquid electrolyte.

Therefore, the equipment can easily do without connecting to the network, but run on rechargeable batteries. The structure of the sensor is such that the air condition is analyzed by determining the level of oxidation of the substance inside the capsule of the device.As a rule, the medium for electrochemical reactions is a galvanic cell filled with a liquid alkaline solution (mainly potassium).

As practice shows, alkali has some disadvantages, including low resistance to carbon monoxide and a short shelf life.

However, some manufacturers prefer to create an electrolytic environment using a mixture of acidic solutions. Such a cell is much more resistant to the effects of third-party molecules and, as a result, more durable.

Gas molecules (in this case CO) come into contact with the electrode of the device, resulting in a chemical oxidation reaction. The electrolyte records the level of voltage that occurs and converts this indicator into the level of gas content. The higher the percentage of waste, the stronger the electrolysis.

The alarm control process is carried out by a small microcircuit in which the specific level of the presence of waste is registered. Therefore, according to the already familiar principle, if the norm is exceeded, the sensor signals danger.

A microcomputer inside the case monitors voltage changes with high accuracy due to increased chemical reactions to CO

To maintain the purity of the active medium along with semiconductor sensors, a carbon filter is often placed in the housing, which traps unwanted molecules mixed with carbon monoxide. Thus, the effectiveness of the device is supported by a chemical system. protection, which reduces the likelihood of false activation.

Some models allow you to replace spoiled electrolyte and refill the galvanic capsule.

The advantages of catalytic sensors and the principle of their operation are demonstrated in the video:

Features of gas sensors

The form factor of some devices requires the presence of a so-called electromagnetic relay, through which the sensor can be connected to the gas pipeline valve plug system.

The main purpose of the system is that such a sensor, when an alarm is triggered, instantly shuts off the gas supply in the pipe, thereby ensuring complete safety.

The relay can be connected as a separate element to control the damper. Some devices already have this system.

Modern equipment also provides a number of functions for notifying about an emergency using a regular mobile phone. In most cases, systems of this kind are typical for imported devices and it is quite problematic to find them among domestic analogues.

However, some manufacturers have taken care of the possibility of connecting additional GSM peripherals to notify the owner of the house via SMS.

The mobile signal transmitter looks like a regular microcircuit. Connection is made according to the instructions included with the CO detector.

Alarm installation process

Most detectors are supplied with a special fastening element onto which the device will later be mounted. It is recommended to mount it on a wall closer to the ceiling.

It should be noted that in European countries, mounting a carbon monoxide detector on the wall next to gas boiler or fireplace is a gross violation. Installation there is allowed only on the ceiling, unlike the CIS, where the sensor is often installed at a distance of at least 1.5 m from the floor.

Since the sensors detect not only carbon monoxide, but also natural gas, you need to understand some installation considerations. When installing a gas alarm system, the device should be mounted at different heights.

If the house is connected to a natural gas pipeline, the sensor should be located closer to the ceiling. In the case of bottled gas - closer to the floor. This is explained by the different densities of gaseous combustible substances.

Natural is lighter than the liquefied balloon version. When there is a leak, it rises upward, while the balloon one, on the contrary, first fills the lower levels of the room.

The choice of location and height for installing the gas presence sensor in the air depends on the type of gaseous fuel. To detect natural gas leaks, the device is mounted at the top; to detect a propane-butane mixture, it is placed at the bottom of the room (+)

When organizing a gas leak prevention system, you should not rely 100% on the functions of the sensor. The device performs only a monitoring task and will not be able to protect people’s lives in the event of an emergency.

Before installation in the required order, you should check ventilation system. If it is working properly, install it.

To independently check the draft, many advise holding a lit lighter or candle near the ventilation hatch - this should not be done under any circumstances! It is better to use a sheet of paper (for example toilet paper)

The process of connecting the sensor to the power supply must be carried out exclusively by a competent specialist, otherwise problems may occur if the power supply is incorrect. You should not neglect this rule, and it is better to contact a professional, because... Someone's life depends on the success of the enterprise.

When choosing a location for the module, make sure that at least one of the sensors is located in the bedroom. This is important to consider. After all, most accidents involving carbon monoxide leaks occur while sleeping.

If the house consists of several floors, it is necessary to provide a fire protection system for each floor of the room through which the components pass autonomous heating system.

When installing the sensor in the same room as the fire source, you should maintain the minimum distance between the fireplace and the sensor. As a rule, for an objective analysis of air, you need to maintain a distance of 4-5 m.

Some sensor models are triggered when the air temperature rises above 50 degrees. This phenomenon occurs when a fire starts in the room and the source of the flame is in close proximity to the device. At the same time, the amount of fume released may not yet reach an alarming level.

The device must be located in such a place that nothing interferes with the air flow. This is typical for cases where the detector mount is located behind a curtain. Air circulation around the sensor is the main point to pay attention to. Because some interior objects may block the inlet of the device and as a result the system will not provide 100% protection.

You can check the functionality of the analyzer in different ways. The easiest way is to buy a special CO2 canister. By spraying it near the detector, you can make sure that the installation operation is correct.

A can of carbon dioxide can be found at any hardware store. You need to be careful when using it, because... the substance is under pressure

It is worth observing some points when carrying out this process.Firstly, under no circumstances should you direct the aerosol stream directly at the device. This is important because the direct concentration of the substance is tens of times higher than the actual amount required to trigger the sensor.

Such an undertaking can either negatively affect the functionality of the sensor or simply disable it. Most manufacturers insist on specialized equipment inspection by qualified technicians. Naturally, the procedure is paid, but this way you can be sure that the CO detector is working properly.

To avoid damage, you need to keep the room clean, trouble-free ventilation, first of all, try to prevent dust from accumulating on the sensor body.

Conclusions and useful video on the topic

The main safety violations when installing gas equipment and recommendations on how to avoid carbon monoxide poisoning:

Carbon monoxide is dangerous because at high concentrations it can kill in a matter of minutes. Detectors will take care of home safety by organizing round-the-clock monitoring of air composition. The choice of device depends only on personal preferences and the price of the device.

Please write comments: share your experience in choosing and using gas analyzers, ask questions. We and site visitors are ready to participate in the conversation and clarify unclear points.