Features of installation and rules for using a household gas alarm. Household gas analyzers for apartments with gas stoves Household device for checking the gas content of a room

Gas heating and hot water supply provides a higher level of comfort than electric, wood or any other, but it is also a source of increased danger. This fully applies to kitchen oven, operating on liquefied or main gas. Methane and other hydrocarbons, when mixed with air in certain proportions, form an explosive substance that ignites from any spark, and carbon monoxide (carbon monoxide) binds to red blood cells and deprives them of their ability to transport oxygen. Therefore, devices are needed that detect both types of hazardous substances before their concentrations reach alarming levels.

In this article we will talk about:

household gas alarms and principles of their operation;
reasons for indoor gas pollution;
types of gas detectors and their capabilities;
installation and maintenance of these devices;
the most popular models.

How does a gas analyzer work?

The basis household gas analyzer– a sensitive element (sensor) that determines the amount of CO and CH 4, C 3 H 8 and others in the air. In household devices, two types of sensitive elements are used:

electrical;
optical.

The operation of electrical sensors is based on the ability of some metals and alloys to change their resistance under the influence of various gases. This type of sensor is most effective for hydrocarbons, so it is used to determine the concentration of propane, butane and methane. The optical sensor element works on a different principle; it determines the ability of air to absorb infrared radiation. This type of sensor is more often used to determine the level of carbon monoxide, which has a higher absorption capacity. Household gas analyzers are less accurate than industrial ones, but even their resolution is sufficient to detect a threat before the amount of gas approaches a potentially dangerous value.

When the sensor detects the presence of carbon monoxide or hydrocarbons in the air, it sends a signal to the actuator, which activates the sound emitter. Some models are equipped with an output relay for connecting an emergency valve and an exhaust fan. When the sensor is triggered, they shut off the gas supply and ventilate the room, reducing the threat level to completely safe and allowing you to immediately begin searching for and eliminating the causes of the leak.

Causes of indoor gas pollution

A properly functioning heating or water heating system eliminates any appearance of carbon monoxide or flammable monoxide in the room, so gas contamination is always associated with a malfunction of one or more devices of this system. Here are the reasons for the appearance of hydrocarbons:

violation of the tightness of threaded connections;
drop in draft and failure of boiler automation;
fire extinction due to excess draft and automatic failure.

Here are the causes of carbon monoxide:

loss of draft due to clogging or destruction of the chimney;
clogging of ventilation ducts;
incorrect operation of the boiler control unit;
violation of the tightness of the combustion chamber.

Types of gas analyzers

All household gas analyzers can be divided into types according to:

power source;
sensitivity;
indication of gas whose concentration has exceeded the norm;
Possibility of connecting actuators.

Based on the type of power supply, devices are divided into battery-powered (autonomous) and 220-volt mains. The former are more reliable in the long term, because their operation does not depend on power outages, but they require regular battery replacement. It's difficult to forget to replace batteries because the alarm sounds long before the batteries are completely depleted. Network devices do not require battery replacement, and more expensive models are equipped with a built-in battery that allows them to operate for a long time even when the lights are turned off.

Devices also differ in sensitivity, but even the weakest ones are able to detect dangerous substances before their quantity becomes a threat. Sensitivity is indicated as a percentage of the lower concentration limit of flame propagation (LCFL). For example, the LEL of propane is 31,000 mg/m3, that is, the content of 31 grams of propane in one cubic meter of air turns the air into an explosive mixture. If the propane content is lower, then it is impossible to ignite this mixture. Inexpensive gas detectors inform about the presence of gas, but do not indicate which of the dangerous substances has appeared in the room. This is quite enough to ensure safety, because no matter what substance appears in the room, the primary actions are always the same. Necessary:

shut off the gas supply;
open windows or activate exhaust ventilation;
call specialists to check the heating and hot water supply systems, as well as the kitchen stove.

More expensive and sophisticated devices not only sound an alarm, but also show which gas concentration has reached a dangerous level. This can be useful in cases where the cause of the leak can be eliminated yourself. For example, a chimney clogged with soot does not provide the necessary draft, so an increase in the level of carbon monoxide may prompt the owner or occupant of the house to clean the chimney in the usual way. A message about a flammable gas leak will prompt the owner or occupant of the apartment/house to check the burners on the stove; perhaps one of them is open.

The cheapest sensors only give an audible signal, so you have to manually close the emergency valve and turn on the exhaust ventilation. More expensive and advanced models are equipped with relays or electronic keys designed to control such devices. Thanks to the relay, you can independently combine all devices into one network with unified control, which will increase the safety of using gas equipment.

Device functions and capabilities

To choose correctly gas detector, you need to understand what functions it should perform and what can be sacrificed. Here is a list of the most important functions, with a brief description:

Audible and optical alarms - usually these are buzzers and lights, the operation of which cannot be ignored when standing next to them. However, if you are in another room and the music is playing loudly or the TV is on, then this function is useless.
Relays or electronic keys - designed to activate one or more devices connected to one signal wire and powered from the network or an independent power source. Most often, they are connected to an emergency valve, an exhaust fan and a powerful siren, which is impossible not to hear even with loud music playing. This function seriously increases the gas safety of your home or apartment, but is useless without other devices.
Possibility of operation from two power sources - batteries/accumulators and a 220 volt network. This feature increases both gas safety and equipment cost.
LCD or LED indicator - this feature increases the cost of the equipment, but makes it more versatile. After all, the indicator displays the mass useful information, from the charge of batteries/accumulators to the percentage of a particular gas in the air. However, this function is of little use for devices that operate on mains power and do not have separate sensors for carbon monoxide and combustible monoxide.
The ability to connect to a GSM/Wi-Fi alarm system or a corresponding built-in unit - this function is very useful if you are away and there was a gas leak at home and the sensor performed all the necessary actions, that is, it turned off the gas supply and ventilated the room. Having received information about the emergency, you will be able to more accurately plan your schedule and find the time and opportunity to call a technician to check the system. However, this function is useless for devices that do not have an emergency solenoid valve and an exhaust fan connected to them.

Installation

Before installation, you must choose the right location, because each gas has its own density. In addition, a lot depends on the humidity in the room, the ventilation system and other factors. Therefore, you can choose the installation location yourself, based on various instructions, or you can entrust it to a gas service specialist. If you decide to do everything yourself, then follow these recommendations:

install the carbon monoxide sensor no lower than 1.8 m from the floor and no higher than 0.3 m from the ceiling;
Place the methane sensor no lower than half a meter from the ceiling;
Place the propane sensor no higher than half a meter from the bottom point of the floor;
the distance to the gas appliance that the sensor must monitor should not be more than four meters;
the distance from the stove or oven to the sensor should not be less than one meter.

You can only install a sensor yourself that is not connected to the emergency solenoid valve. If you want to install a sensor connected to a valve, then both the selection of the installation location and the installation and connection must be performed by a gas service employee. Moreover, first the engineer of this service will draw up a project and only after that the worker will install the sensor, cut a valve into the pipe and connect them to each other with a wire (if they are not connected by a radio channel, Wi-Fi network, or GSM units).

Service

You can only wipe the dust off the sensor yourself, and calibration and performance testing must be carried out by a gas service worker with special equipment. An attempt to clean or adjust the sensor yourself will most likely result in damage to it. It is enough to wipe the sensor housing with a clean, slightly damp cloth once a quarter. If you think that the sensor is faulty or is not working correctly, then immediately call a gas service worker. He will check gas composition air and, you will either make sure that everything is in order with the sensor, or you will understand that it needs to be changed.

Description of models

If you are going buy a natural gas alarm or carbon dioxide, we present to your attention several of the most popular models:

SZ-1-R – gas alarm natural gas, powered by batteries or accumulator. Equipped with light and sound indication, as well as a relay for connecting additional devices. When triggered, it turns on the solenoid valve and sends a signal to the control room operator console or communication units. Sensitivity 10 and 20 LEL. The cost of the device is 4 thousand rubles.
The SGK-2-B system consists of natural and carbon monoxide sensors, as well as an electromagnetic emergency valve, connected by a 5 m long signal cable. You can connect to them a remote control panel with sound and light indication, which shows which gas has exceeded the permissible concentration. The system supports connecting additional units (GSM, Wi-Fi, radio channel). Sensitivity 10–20 LEL. The cost of the kit depends on the diameter of the gas pipe and amounts to 7–9 thousand rubles.
Sapsan GL-100A is a gas leakage monitoring system consisting of a natural gas sensor and a solenoid valve. The sensor and valve operate from the same power source (batteries or accumulators). Sensitivity 20 LEL. The cost of the set is 3 thousand rubles.
"Kenar" GD100-CN - methane and carbon monoxide leak sensor. Sensitivity 10 LEL. For propane and butane, sensitivity is 20–30 LEL. The sensor operates on a 220 volt network; there is no built-in battery. Supports connection of solenoid valve and fire alarm siren. Cost 2600 rubles.

It is difficult to imagine modern life without the use of gas, and therefore without the equipment that runs on it. Gas is used for cooking, home heating, etc.

But all devices that use gas are potentially dangerous; their use requires strict adherence to certain rules. But despite all this, we constantly hear about new incidents related to gas explosions.

Usually the cause of all these accidents and accidents is gas leakage. And even conscientious consumers who follow all the rules for using gas appliances may experience misfortune, as the equipment ages and periodically breaks down.

To prevent the serious consequences of a gas leak, gas detectors are used.

The main function of these devices is to control the level of flammable gases in the air. When a certain gas concentration is reached, the device turns on a sound and light warning of a leak, which allows people to respond in a timely manner and prevent an accident.

Gas alarms are widely used in industrial facilities where gas is used, in boiler rooms and in domestic premises. Therefore, depending on their purpose, devices are divided into industrial and household.

Industrial ones have a more complex structure and are complexes consisting of and.

Household devices are three times simpler and are designed to measure the concentration of gases often used in everyday life:

methane (CH4);
propane(C3H8)
carbon monoxide (CO), which is known as carbon monoxide.

Carbon monoxide is the most dangerous because it has no odor, color, or taste, unlike propane and methane, which can be detected by smell. It combines with hemoglobin in the blood 300 times faster than oxygen and blocks its entry into the blood. Acting on the brain and nervous system, carbon monoxide kills very quickly.

Even a small, but chronic gas content in the premises leads to chronic intoxication of the body, which is manifested by such symptoms as:

nausea;
headache;
decreased mental abilities;
muscle weakness;
memory impairment.

All these problems can be avoided by using gas detectors that can notify you of a danger in time.

The main reasons for the increase in indoor gas pollution

Most often, such reasons are equipment malfunctions or incorrect operating modes of gas appliances, which include kitchen gas stoves, geysers for heating water.

The main faults are:

Regular preventive maintenance of gas equipment is the best prevention of accidents. But, nevertheless, installing a gas detector is always advisable.

According to the operating mode, gas alarms can be:

with constant mode;
with periodic.

Depending on the type of sensors used, they are divided into:

optical;
chemical;
thermochemical.

The gas detector can be:

monoblock, when sensors are built into the alarm;
control unit with remote sensors.

Depending on the amount of gases being determined, devices can be one-component or two-component. The former can detect only one type of gas (carbon monoxide or methane), while the latter can detect both.

Devices with remote sensors can have one or two measurement channels. A sensor is connected to each channel that detects any type of gas. Although you can connect the same sensors to all channels.

The use of remote sensors makes it possible to control the level of gas pollution at a distance of up to 200 m.

If there are several sources of possible gas leakage, then it makes sense to connect several monoblock devices to one actuator capable of shutting off the gas.

Cases of devices from different manufacturers can have different sizes, shapes and colors.

Main functions of the gas detector

These devices are multifunctional devices, and alarms from different manufacturers can be equipped with a different set of capabilities. Therefore, when purchasing, you need to focus on the specific needs of your system.

The main functions inherent in almost all types of sensors:

sound and light warning of exceeding gas levels;
output relay, through which you can connect such devices as an additional siren, exhaust fan, signal to the control panel and some others;
the ability to connect an electromagnetic device that cuts off the gas supply;
outputs for connecting additional equipment from the sensor;
Some devices have the ability to operate from an autonomous power source.

Installation of a household alarm

Most often, household appliances are powered from a 220 V mains voltage.

You can install the device yourself, but you must take into account all installation requirements regulated by the following regulatory documents:

Federal Law No. 384-FZ;
SNiP 42-01-2002;
SP 41-108-2004;
SP 62.13330.2011.

Installation is performed in the following order:

Selecting the location for installing the alarm and preparing the project.
After installing the device, the cables of the executive systems are connected to it.
The equipment is being configured.
System performance testing.

In case of any difficulties, it is better to contact the gas service.

The alarm is mounted on the wall in the place where a gas leak is most likely (near the boiler, gas water heater or meter, near the gas stove). The horizontal distance from the gas appliance should not exceed 400 cm.

There are places where it is strictly prohibited to place a gas detector:

next to or near open windows;
near uninsulated chimneys;
in places where the device may come into contact with grease, dust, steam or ash;
no distance less than 100 cm from gas ovens and burners;
in places where gasoline, thinner or paint are stored.

The mounting locations of the sensors are also regulated depending on what kind of gas the alarm should detect:

carbon monoxide - no lower than 180 cm from the floor and no higher than 30 cm from the ceiling;
methane - no lower than 50 cm from the ceiling;
propane - no higher than 50 cm from the floor (if there are any recesses in the floor where gas can accumulate, an additional alarm must be installed in them);
a combined sensor that detects both methane and carbon monoxide - at a distance of 30 - 50 cm from.

The installation height depends on the gas density. Propane is heavier than methane and carbon monoxide, so it accumulates near the floor.

If you decide to install not only a gas alarm, but also a shut-off valve, you will have to contact a specialized company that has a license for such work.

Checking and servicing the alarm

Metrological verification of the device is carried out annually. It is prohibited to check the functionality of the sensors yourself. This can disable them.

If you independently discover a malfunction of the device, you need to call the gas service.

Otherwise, maintenance of the gas detector consists mainly of removing dust from its housing.

The warranty period for the sensor is usually no more than 2 years, but its average service life is up to 8 years.

The following devices from Russian manufacturers are mainly presented on our market:

STG-1, STG-3, SOU-1 (SPO "Analitpribor");
SZ-2 (“SGK”);
BUG, ECO (Gazotron-S).

There are also imported gas analyzers from Seitron, but experts advise purchasing domestic products, since their repair and replacement are much cheaper.

The cost of a domestic signaling device ranges from 1,400 to 4,000 rubles, depending on the number of its functions.

As you can see, every family can purchase and install such a device. As for its necessity, it is obvious. Such a small and inexpensive device can prevent terrible accidents involving loss of life and destruction of buildings.

What is a gas alarm, what functions does it perform and how does it ensure safety? How does the alarm work with additional devices, what is their cost and is it possible to install them yourself? You will learn about this and much more from this article.

What is a gas alarm

Gas alarms are devices that provide continuous monitoring of the content of flammable gases and carbon monoxide in the air of rooms where gas equipment is installed. Alarms have long been used in industry to ensure the safety of facilities, but they began to be used for gasification of residential buildings relatively recently.

Types of signaling devices. Which to choose

There are two types of alarms: industrial and household.

More stringent requirements apply to industrial ones and they often work in conjunction with a control panel, which receives signals from several gas sensors and which provides control over the concentration of the measured parameter in the air. The requirements for a household sensor are not so stringent. Its main task is not to measure and display the concentration, but to operate if the value of the monitored parameter exceeds the set value. Also, a household sensor must provide a number of reactions to gas contamination.

Gas alarms differ in the controlled parameter; for household sensors, three main types can be distinguished:

methane (CH 4);
propane (C 3 H 8);
carbon monoxide (carbon monoxide, CO).

There are also combined sensors that simultaneously monitor the concentrations of fuel and carbon monoxide.

For a room in which gas-fired heating equipment is installed, a combined sensor (CH 4 + CO or C 3 H 8 + CO) is best suited. For a room with stove heating, a carbon monoxide sensor will be sufficient.

When choosing a signaling device, it is necessary to take into account the power supply of the sensor and the devices with which it will interact if triggered; the optimal option is 220 V. The same power supply should be selected for related equipment, which will be discussed below.

Price table for gas alarms:

Sensor type	Controlled parameter	Switching external electrical networks	Shut-off valve control	Cost, rub.
SGB-1-2	CH 4 - 0.1%, CO - 0.01%	-	-	1269,00
SGB-1-7	CH 4 - 1%, CO - 0.005%	-	-	1724,00
Guardian of the Mind	CH 4 - 0.5%, CO - 0.01%	-	-	1282,00
Guardian 110UM	CH 4 - 0.5%, CO - 0.01%	+	+	1638,00
Guardian UM-005	CH 4 - 0.5%, CO - 0.005%	-	-	1387,00
Guardian 110UM-005	CH 4 - 0.5%, CO - 0.005%	+	+	1684,00
SGB-1-2B	CH 4 - 0.1%, CO 0.01%	+	+	1545,00
SGB-1-7B	CH 4 - 1%, CO - 0.005%	+	+	2073,00
Varta 2-03	CH 4 - 1%, CO - 0.005%	+	+	2252,00
Warta 2-03B	CH 4 - 1%, CO - 0.005%	-	-	1850,00
UKZ-RU-SN4-SO	CH 4 - 0.5%, CO - 0.002-0.01%	-	+	5664,00
SGB-1-4.01	CO - 0.01%	-	-	1159,00
SGB-1-4.01B	CO - 0.01%	+	+	1393,00
UKZ-RU-SO	CO - 0.002-0.01%	-	+	3658,00
SGB-1-6	C 3 H 8 - 0.46%	-	-	1270,00
SGB-1-6B	C 3 H 8 - 0.46%	+	+	1504,00
Maxi/S	CH4 - 1%, C3H8 - 0.4%, CO - 0.005%	-	-	1112,00
Maxi/K	CH 4 - 1%, C3H8 - 0.4%, CO - 0.005%	-	+	1421,00

What does the alarm react to?

The value of the controlled parameter in the air at which the alarm will go off is the same for most household sensors and is:

Methane - 0.1-1%.
Propane - 0.46-0.05%.
Carbon monoxide - 0.005-0.01%.

The percentage values of methane and propane are approximately five times less than the lower concentration limit of flame propagation for these gases. This means that the alarm will go off much earlier than the gas content in the air reaches an explosive concentration.

What functions can a gas alarm perform?

Due to their design, household gas alarms are multifunctional devices. The list of capabilities of each alarm device is individual. Here are the main ones present in most sensors:

light and sound warning. When there is gas contamination, the light indicator lights up and a loud sound signal appears;
possibility of connecting an electromagnetic gas shut-off valve;
relay output, through which it is possible to connect electrical devices (exhaust fan, separate siren, signal to the fire or dispatch console, etc.);
power outputs for direct connection of additional equipment from the sensor;
Some sensors have the ability to operate from an independent power source.

What is a solenoid shut-off valve? Its types

An electromagnetic shut-off valve is a device that is mounted at the entrance of a gas pipeline to a room and is a valve that, when an electrical signal is applied to its coil, must shut off the gas supply to gas appliances.

Shut-off valves differ in:

nominal diameter. For domestic needs, valves Dn 15, 20, 25 are often used;
nutrition. For domestic needs, optimally - 220 V;
permissible pressure. For low pressure gas pipelines - up to 500 mbar;
by valve type: normally open and normally closed.

The type of valve is the most significant characteristic for working in conjunction with a gas alarm.

A normally open (pulse) valve is a manually cocked valve. During operation, no voltage is supplied to its coil. When the gas alarm is triggered, a short-term electrical pulse arrives from the sensor to the valve coil, causing the sensor to operate and cut off the gas. The designation of this type of valve is N.A.

A normally closed valve is also a manually cocked valve. However, in order to cock (open) it, it is necessary to apply voltage to its coil. When the gas alarm goes off, the voltage on the coil disappears and the valve shuts off. The designation of this type of valve is N.C.

For domestic use, a normally open valve with a 220 V power supply is more suitable. This is due to the fact that a power outage will not cause it to operate. This makes it possible to use non-volatile gas appliances (stove, water heater). There is also no need to waste electricity to keep the valve open.

The only inconvenience with such a valve may arise if it works in conjunction with a gas sensor, which, when the power is turned on, automatically checks the serviceability of its outputs. After turning on the power, such a sensor will send a pulse to the valve, causing it to operate. When choosing a sensor, you must carefully study the sequence of its operation.

Information on valve type, power supply, permissible pressure and nominal diameter is indicated on its label.

Cost of solenoid shut-off valve: type N.A., 220 V, Pmax: 500 mbar:

Installation and connection of a gas alarm

You can install a household gas alarm yourself. To do this, you need to correctly place the sensor, following the instructions in the passport, and supply power to it. You also need to connect additional devices according to the scheme provided in the product passport.

IN modern projects for gasification, the installation location of gas detectors and their quantity are indicated in project documentation. Also, assistance in choosing the right place to place the sensor can be provided by the gas service, guided by regulatory documents.

The alarm should be placed on a vertical wall, in places where the probability of gas leakage is greatest (near the boiler, water heater, gas meter, stove), at a horizontal distance of no more than 4 meters from the gas appliance.

Where the alarm should not be placed:

at a distance closer than 1 meter from gas burners and ovens;
in places where the alarm device may be exposed to steam, ash, dust and grease;
near ventilation ducts and open windows;
in places where paint, solvents, gasoline and similar materials are stored;
in the immediate vicinity of uninsulated chimneys.

It must be taken into account that for each type of alarm device (CH 4, C 3 H 8, CO or combined), the mounting height of the sensor will be different. This is due to the different densities of air and gas, the area of its accumulation in the room:

methane (CH 4) - not lower than 0.5 m from the ceiling;
carbon monoxide (CO) - at a height of 1.8 m from the floor, or higher, but not closer than 0.3 m to the ceiling;
combined sensor (CH 4 + CO) - in the range from 0.3 m to 0.5 m to the ceiling;
propane (C 3 H 8) - no higher than 0.5 m from the floor. If there are holes, trenches and other recesses in the room where flammable gas can accumulate, it is also necessary to install an additional alarm in them.

Attaching a household alarm to the wall often does not even require opening the housing. The sensor is mounted on dowels through the mounting holes in the housing.

Connecting the shut-off valve

The installation of a shut-off valve must be carried out exclusively by specialized organizations that have licenses for this type of work. The valve is connected to the signaling device according to the diagrams specified in the valve and signaling device data sheets.

Alarm maintenance. Costs for periodic verification

A gas alarm installed in a residential building requires virtually no maintenance. The only thing that is necessary is to periodically wipe the grille in the sensor housing from dust and cobwebs.

Once a year, the alarm device must undergo metrological verification. This service is paid. Under no circumstances should you independently check the operation of the alarm by applying a 100% gas mixture to it, for example, from a gas lighter. This may damage the sensor's sensing element.

It is advisable to purchase sensors domestic producers. This will allow, if necessary, to send the sensor for repair, which is much cheaper than buying a new one.

Remember that a gas alarm is an important and relatively inexpensive safety element that may very well save your life one day. The choice is yours!

A powerful explosion collapsed the entrance apartment building in Volgograd, located at 60 Universitetsky Ave. 4 people died, another eleven were hospitalized in serious condition. The cause of the collapse was a domestic gas explosion in one of the apartments at the ill-fated entrance. One of the residents simply forgot to close the knob of the burner on the kitchen stove...

Similar messages appear in news feeds with enviable regularity. You wonder why people learn only from their own mistakes and do not want to use the bitter experience of others? Modern gas stoves have smart burners - with a fire extinguishing sensor. There is a fire - the supply is on, there is no fire - the gas supply stops. Convenient and safe.

But! Old stoves are completely unsafe. The classic “your milk has run away” can lead to disaster and the demolition of an entire entrance – as happened in the story above.

By installing an inexpensive gas alarm in the kitchen, half of these dramas could be avoided. Long before dangerous concentrations are exceeded, the sensitive sensor will trigger and give a loud warning signal.

Gas alarm - what is it?

A gas analyzer or gas leak detector is a device that detects dangerous concentrations of certain volatile fractions in the air. Signal the presence of methane CH 4, propane C 3 H 8, carbon monoxide CO.

Design

Structurally, the vast majority of household gas alarms are made in the form of a monoblock - the sensor, control module and power supply are enclosed in a common housing. Sometimes the sensors are moved some distance from the control unit. But such designs are several times more expensive and are extremely rare.

The gas analyzer needs tiny power. Typically, devices require only a few watts to operate. Kenary GD100, for example 3 W. Gas analyzer HONEYWELL 6618B 2 W, Dadzhetovsky MT8085 4 W.

Very often, power is provided by a 220V network, through the socket into which the device is connected. Sometimes, for reliability, power is supplied from an autonomous source. These can be 9V or 12V batteries.

Types of sensors and operating principle

The heart of any gas analyzer is, undoubtedly, the gas sensor. They come in different designs. They differ in measurement accuracy, activation speed, life cycle period and cost.

Semiconductor. The principle is as follows: when a controlled gas is exposed to a platinum filament, the resistance changes. Operates from -20°C. Accuracy 0.001%. The sensor initialization time is no more than 2 minutes. They have miniature sizes at a relatively low cost. The most popular type of sensor in household gas alarms. In terms of accuracy, they are much inferior to electrochemical sensors.

However, in Europe, control standards are becoming stricter all the time. The use of semiconductor sensors will be discontinued in the near future due to their low accuracy.

Electrochemical. The gas concentration is assessed based on the degree of progress of the electrochemical process. Actually, this is what gave this type of sensor its name.

Features: very high measurement accuracy, ideal tool for analyzing the concentration of certain gas fractions. They have a large resource of work. They are used in high-precision signaling devices in production. Where high resistance to vibration and shock is needed.

Infrared. Concentration analysis is performed based on the results of infrared irradiation of the incoming gas. Currently, they are considered the most accurate sensors.

They have only one drawback - their high price compared to electrochemical and semiconductor ones.

Methane, propane, carbon monoxide

Carbon monoxide CO

Molecular weight = 28. Almost equal to the weight of air, slightly lighter (28 versus 29).

There is no other poison that kills more people. Carbon monoxide is the absolute champion. Poison, colorless and odorless. When in contact with carbon monoxide, the body does not recognize it as a foreign agent and does not turn on its defenses. On the contrary, it “opens its arms” towards the invisible killer. Carbon monoxide displaces oxygen, and a person dies from hypoxia. He just falls asleep, not realizing what is happening to him.

Installation: at human height.

Methane CH4

Molecular weight = 16, lighter than air.

I. Explosive. Refers to toxic substances acting on the central nervous system. Colorless gas, odorless. In everyday life, they are enriched with odorants so that people notice the leak in time. Used to supply gas to household stoves in apartments. Often called natural gas, main gas. Methane leakage is the main cause of explosions of apartments and entire entrances in apartment buildings with gas stoves.

Installation: one meter from the ceiling.

Propane C3H8

Molecular weight = 58, heavier than air.

I. Explosive, flammable. Has a specific smell. Refers to toxic substances acting on the central nervous system. It is used in everyday life to supply gas for portable stoves from liquefied gas cylinders.

Installation: one meter from the floor.

Installation locations

Carbon monoxide and propane sensors are installed no higher than 25 cm from the floor, methane sensors are installed under the ceiling. Not lower than 35 cm from the ceiling. Why this is so is clear from the description chemical properties dangerous gases. Sensors should be located in areas where they may be concentrated. It's simple.

Sometimes there are combined detectors, for example, methane + carbon monoxide. It is better to avoid them and take two separate ones. Carbon monoxide should be placed at the height of human height, and methane - at the ceiling. There will be much more sense.

Installation examples household gas analyzers in the kitchen

Shut-off valves and solenoid valves

Obviously, the process of shutting off a gas pipe can be automated. Often a solenoid valve is installed on the pipe. As soon as the alarm detects danger, the siren immediately turns on and the valve shut-off switch is activated - the pipe is reliably closed, and the supply of main gas is stopped. This can be a great help when an accident occurs while you are away.

Ratings and reviews of cut-off devices vary. Many are afraid of the unreliability of such devices, considering such a measure to be complex and dangerous. And they are limited to installing only a signaling device.

Installing solenoid valves is indeed not an easy procedure. You will not be able to install a cut-off device in your home yourself. You will need to call a gas service specialist. By the way, before purchasing a valve, you need to know the diameter of the line. They come in ½ or ¾ inch.

Gas detector "Kenar GD100". It can be installed anywhere. If desired, 1/2 or 3/4 cut-offs are connected

Conclusion

Take care of yourself. Your family, close people. There is nothing more valuable than your life. Honestly!

Any room in which gas equipment is used must be checked for the level of concentration of gas combustion products in the air. To measure this parameter and ensure safe conditions In everyday life and in industry, a special device is used - a gas sensor. What kind of device this is, what functions it performs, is disclosed in the article.

What is a gas sensor

This is a high-precision measuring device designed for continuous automatic monitoring of the amount of hazardous gases contained in the air. Gas alarms are used in industrial, domestic and communal premises.

They are produced as a separate device, which can be placed autonomously in a suitable location. There are also alarms included in the kit for shut-off valves.

The device is equipped with an analyzer that can respond to changes in the concentration of certain gases. Various sensors are used to measure the amount of gas in a medium. They instantly react to an increase in the concentration of gases emanating from gas appliances. At a high level of gas contamination, the sensor generates a light and a danger signal.

Modern sensor models are equipped with a liquid crystal display that displays the measured values. The built-in memory allows you to record the received data and store all measurement results.

The display also displays information about the performance of the device and any existing problems. This function allows you to promptly change worn out elements.

Types of gas detectors

Gas monitoring sensors are divided into two main types: household and industrial. Detectors for domestic use provide a number of reactions to exceeding the established gas concentration parameter. The main tasks of an industrial sensor are to measure and display gas contamination indicators on the display. Industrial devices are used to solve more stringent problems and are often used in conjunction with a control panel, which receives a signal from gas sensors.

Depending on the type of gas being measured, the following types of alarm devices are distinguished:

Methane.
Propane.
To measure or carbon monoxide.
Combined multicomponent.

According to the installation method, gas sensors are:

Stationary - they operate only from the mains and are located close to the power source.
Portable - powered by a built-in battery.

Functionality of gas sensors

The gas sensor is a multifunctional device and has the following capabilities:

Sound and light notification. If the device reacts to gas contamination, its indicator lights up and a loud beep sounds.
Possibility of connecting a gas shut-off valve.
Availability of a relay output for connecting additional electrical devices: a separate siren, fan, mechanism for a firefighter or dispatch console.
Built-in autonomous power supplies.

Installation Features

Installation of a gas sensor depends on the type of device and is carried out subject to certain rules. You can install a household alarm yourself, following the manufacturer's instructions. Each sensor model comes with a passport with a device installation diagram.

When choosing a location for the device, it is better to seek help from gas service representatives. They know regulations and can choose the right place.

Typically, gas alarms are placed on the wall near appliances that operate on gas (near the water heater, gas stove, boiler and meter). The distance between the sensor and the gas appliance should not exceed 4 meters.

How not to install a gas sensor:

At a distance of less than 1 meter from ovens and gas burners.
In places with high dust levels.
Close to windows or ventilation ducts.
Near storage areas for gasoline, paints, and solvents.
Near uninsulated chimneys.

Industrial alarms are installed by gas specialists using special technology.

Gas detectors for boiler rooms

Boilers and other heating devices operate on liquid, gaseous and solid fuels, the combustion of which may produce excess amounts of methane and carbon monoxide in industrial premises. This risks poisoning personnel and creating an explosive situation. Gas sensors in the boiler room allow you to timely detect high concentrations of gases and prevent emergency situations. All boiler rooms must be equipped with gas control alarms in compliance with the following requirements:

the sensor must operate continuously;
the sensitivity of the device must be selective;
the presence in the device of a program for turning on/off emergency ventilation until the concentration of methane and carbon monoxide reaches normal values;
alarms from several devices must be connected to a common remote control;
availability of a GOST certificate of conformity;
The device must be of a safe design and have the longest possible service life.

Gas sensor cost

You can purchase a gas sensor in every specialized store. The price of this device depends on the brand and functionality. Thus, a household alarm for propane or methane produced by Promgazenergo costs almost 1.5 thousand rubles. An automatic gas sensor from PKF Energosystems costs about 6 thousand rubles. It can be used in domestic and industrial premises. The price of imported models can exceed 10 thousand rubles.