The best gas analyzers: characteristics of the models. How to choose a household gas analyzer: manufacturer reviews

Work safety in production depends on the concentration of gas in the surrounding area. To determine the content of gases in air and liquid solutions, special devices are intended - gas analyzers.

Analyzer classification principles

Signs by which gas analyzers are classified:

• intended for domestic or industrial purposes;
• the ability of the device to record the content of one or more gases;
• mobility;
• the number of sensors performing detection in one or many channels;
• mechanism for performing functions.

We will look at 5 of the most popular, well-proven models of gas analyzers.

Oximeter SX716

A compact portable gas analyzer quickly records the oxygen concentration in liquid media using a polarographic sensor. The advantages of the device are as follows:

• determines oxygen content and temperature;
• the result can be displayed in user-friendly units (concentration in mg / l, ppm,%; temperature in ° C, ° F);
• memory stores 100 readings;
• the range of determined gas concentrations and temperature readings includes all possible values;
• automatic shutdown if the device is not used for 10 minutes.

The SX716 Oximeter can be used at home to monitor gas levels in home aquariums. The device is applicable in laboratories when carrying out scientific research and determination of performance indicators at power plants, metallurgical, pharmaceutical enterprises.

Meter AZ8603

This is a unique device that performs the following definitions:

• oxygen concentration in solution;
• temperature;
• salt content;
• electrical conductivity;
• pH value.

The meter has a memory for 99 parameters, it can control the quality of fresh and sea water.

Analyzer SM207

A narrowly targeted device that records the concentration of formaldehyde and air humidity. Formaldehyde is now often used in the manufacture of furniture and medicines. Given the harmful effect of the gas on the human body, its content in the ambient air must be carefully controlled. The compact, lightweight device is easy to use. The set values ​​appear immediately on the display.

ZG1163R device

It is an accurate gas analyzer that detects the concentration of carbon dioxide (carbon dioxide) in a room. Due to diffusion, CO 2 molecules get to the IR detector built into the device. Besides, desktop device measures:

• air temperature;
• moisture content (water vapor).

The concentration of carbon dioxide must be monitored in the following areas:

• in gyms;
• in kindergartens;
• in schools;
• in hospitals.

If indoors poor ventilation and hermetically sealed windows, the carbon dioxide content in the air may rise.

AR8700A Meter

Compact, ergonomically shaped device with electrochemical sensor detects concentration carbon monoxide(carbon monoxide). The device fits into a pocket, purse. Determination of carbon monoxide is vital in all rooms where fossil fuels are burned:

• in dachas with stoves and fireplaces;
• in garages with running cars;
• in apartments with gas stoves and water heaters;
• in production in boiler rooms.

In just a second, you can find out the content of a deadly gas in the air. You will get the necessary indicators using a gas analyzer. You can order devices of excellent quality at reasonable prices on the EcoGuru website. The store guarantees the delivery of devices throughout Russia.

Gas analysis is a must chemical production as well as many industrial enterprises... Such studies are procedures for measuring a particular component in a gas mixture. For example, in mining enterprises, knowledge of the characteristics of the air in a mine is a safety issue, and ecologists thus determine the concentration of harmful elements. Not so often, such analyzes are used for domestic purposes, but if such a task arises, then it is best to use a gas analyzer. This is a measuring device that allows you to determine the composition of the gas mixture. At the same time, there are many varieties of this device, which have fundamental differences.

Gas analyzer device

Despite the many design variations of the device, there is a set of basic components that are present in each model. First of all, this is the case, which contains all the working elements of the gas analyzer. The fact is that such devices require a high degree of protection, therefore, serious requirements should be made to the outer shell. Almost every device requires power supply - accordingly, the battery can also be considered as an indispensable part of the device. Next, it is worth moving on to a more responsible component. This is a primary converter, that is, a gas analyzer sensor or a sensing element that provides direct data for measurement.

I must say that there are several types of such sensors, including thermocatalytic, infrared and electrochemical. The task of this element is to convert the desired component of the gas composition into an electrical signal. After that, a measuring-indicating device comes into operation, which processes this signal and demonstrates its indicators in the form of an indication or display on the display. Now it is worth considering the types of existing gas analyzers.

Thermochemical models

In devices of this type, a measuring principle is provided by determining the thermal effect from chemical reaction with the participation of the required component. As a rule, the oxygen oxidation technique is used during operation. Therefore, such a device can be considered as an oxygen gas analyzer, and the function of catalysts is performed by hopcalite, which is deposited on a porous support. Measurement of oxidation indicators is carried out using metal or semiconductor thermistors. In some cases, the surface of platinum thermistors also acts as a catalyst. Typically, thermochemical models are used to work with combustible gases and vapors, as well as in the process. It can be used to determine, for example, the oxygen content in hydrogen.

Magnetic devices

V this case we are also talking about devices oriented to the determination of oxygen. A gas analyzer of this type monitors the indicators of the susceptibility of magnets relative to the investigated medium, depending on the concentration of oxygen in it. It would seem that this component can be determined by other types of the device, but there is one feature. The fact is that a magnetic gas analyzer is a meter that is capable of determining the concentration in complex mixtures with a higher accuracy. You should also distinguish between magnetomechanical and thermomagnetic devices. In the first case, the device measures the force acting in an inhomogeneous magnetic field on a sensitive element placed in the medium under study - for example, a rotor. The reading will depend on the medium temperature and pressure. The principle of operation of thermomagnetic models is based on a convention that arises when a gas mixture interacts with inhomogeneous temperature and magnetic fields.

Pneumatic models

Such devices work on the basis of measuring indicators of viscosity and density. For this, the data of the hydromechanical properties of the flow are analyzed. It must be said right away that there are three options for such devices: throttle, jet and pneumoacoustic. A throttle gas analyzer is a device with a transducer that measures when a gas mixture is passed through it. Jet-type models measure the dynamic characteristics of the head of the gas mixture flowing out of the nozzle. Typically, devices of this type are used when working with nitrogen and chloride compounds.

The pneumoacoustic device includes two whistles with approximately equal frequencies of the order of 4 kHz. The first whistle passes the analyzed gas through itself, and the second - the composition for comparison. As a result, the air gas analyzer allows you to compare the vibration frequencies, converting the indicators into pneumatic vibrations using an amplifier. To provide a signal, type is used.

Infrared models

The principle of operation of such gas analyzers is based on the selective absorption of vapor and gas molecules by infrared radiation. It is important to take into account that the device provides for the absorption of those gas mixtures, the molecules of which contain at least two different atoms. The specificity of molecular spectra in various gases also determines the increased selectivity of such devices. For example, there are conventional and dispersive versions of the transformer. A dispersive gas analyzer is a device that uses radiation generated by monochromators, that is, or prisms. In ordinary representatives of this class, non-monochromatic radiation is used, which is provided due to the peculiarities of optical schemes. For this, light filters, special radiation receivers and other components are used. Also, infrared gas analyzers can use non-selective radiation detectors - in particular, thermopiles, bolometers and semiconductor components.

How to use the device?

It is important for the user of the device to become familiar with the display or other device for displaying information with which the device is supplied. As a rule, modern displays show the date, as well as several fields for data on the composition of the gas mixture. The manual of the gas analyzer in a specific configuration will allow you to get complete information about the meaning of the fields and channels of the device. Actually, the control of the device functions also depends on the specific model. As a rule, it is enough to activate the device while in gas environment... Further, when the threshold values ​​for the concentration of the desired component are reached, the device will give a signal. In some models, light indication is also possible. At the same moment, the main lines about chemical composition the gas mixture and the properties of a particular component to which the device has been tuned.

Device verification

Like any gas analyzer, it needs to be verified. This procedure will allow you to assess the technical condition, performance of the device, as well as its compliance. Most often, failures in performance are subject to portable gas analyzers therefore they should be serviced more frequently. So how is verification done? The procedure is performed on a special test bench. It begins with an inspection of the device, testing the replacement of faulty elements. This is followed by the calibration measures and the necessary settings.

Direct verification involves the use of a device to assess the concentration of a specific component in a compressed gas cylinder. That is, special mixtures are used, with the help of which gas analyzers are checked for the analysis of a specific component.

How to choose the right individual gas analyzer? Finding out the expert's opinion - we bring to your attention the article by A.P. Sitnikov - head of the analytical sector of FSUE "SPA" Analitpribor ".

Currently on Russian market of individual gas analyzers, there is a huge number of both domestic and imported devices. At the same time, almost all of them have the necessary permits (Certificate of Type Approval of Measuring Instruments, Declaration of Conformity of the Customs Union, Certificate of Conformity of the Customs Union). However, not all gas analyzers can be used as safety devices for monitoring the content of toxic and flammable gases in the air. working area.

One of essential elements to ensure the safety of personnel at facilities hazardous for the release of toxic and combustible gases is the use of stationary and individual gas analyzers. And if for right choice Stationary gas analyzers are responsible for the design organization that carried out the project of the object, then the specialists of the enterprise, as a rule, employees of the labor protection departments, are directly responsible for the portable and individual gas analyzers and alarms used.

Working for a long time at FSUE "SPO "Analitpribor", due to the nature of my duties, I often faced investigations of accidents related to poisoning with toxic gases or explosions of flammable gases and vapors. With regret, I would like to note that quite often the specialists of enterprises responsible for safety engineering have quite serious troubles and bear administrative responsibility due to the use of devices that do not comply with the regulatory documents in force in the Russian Federation. Nevertheless, there are a number of general criteria for the selection of equipment, compliance with which allows you to select equipment that is optimal for the purpose of ensuring the safety of personnel and fully complies with regulatory documents, which eliminates the occurrence of problems during inspections carried out by regulatory authorities and investigations of accidents.

The proposed criteria for the selection of devices can be conditionally divided into three groups: legal; technical is required elements, and price - related to the financial position of the enterprise. So, in order:

Legal criteria

1. Availability of the necessary permits: a Certificate of Approval of the Type of Measuring Instruments, a Declaration of Conformity to the Technical Regulations of the Customs Union, as well as a Certificate of Compliance with the Technical Regulations of the Customs Union (for explosion-proof equipment) - mandatory documents, without which the use of devices at all facilities, except for household sector, it is simply impossible, and even there it is better to play it safe. The last two documents are obligatory by the decision of the Board of the Eurasian Economic Commission No. 293 dated December 25, 2012 "On uniform forms of the certificate of conformity and declaration of conformity with the technical regulations of the Customs Union and the rules for their registration."

Certificate of compliance with technical regulations The Customs Union is required to permit the circulation of goods in the territory of the CU, and indicates that the quality characteristics correspond to the accepted standards technical regulations. This document operates on the territory of three states: the Republic of Kazakhstan, the Republic of Belarus, Russian Federation... The certificate of the customs union not only allows the unhindered circulation of products within the CU, but also allows you to avoid bureaucratic delays that previously artificially slowed down the turnover.

It gives the right to sell goods on customs territory of the CU states without additional delays in the form of certification procedures within countries, where the legislation requires additional mandatory verification measures.

The resulting declaration of the Customs Union gives manufacturers the right to carry out trade in the territory of the states, without additional registration of documents adopted within the participating countries: a declaration of conformity in the GOST R system, a GOST R certificate.

You must make sure that these documents are available before deciding on the purchase of devices. As a rule, manufacturers post these documents on their websites, if not, then they must be requested.

2. Compliance with the current all-Russian and sectoral regulatory framework. Thus, the main regulatory documents for instruments for the control of toxic gases in the air of the working area are: GOST 12.1.005-88 (Amendment N1 of 2000) "General sanitary and hygienic requirements for the air of the working area" and GN 2.2.5-1827-03 "Hygienic standards" from 21.12 .2003 These documents indicate the values ​​of MPC.z. for toxic substances and the frequency of their control depending on the hazard class of the substance. Moreover, the data on MPC are indicated in mg / m3, respectively measuring instruments must have units of measurement - mg / m3. It is allowed to use gas analyzers with other units of measurement, for example ppm, with the following restrictions:

• limits of permissible error of concentration measurements harmful substances in the air of the working area equal to MPC or more, should be +/- 25% of the measured value with a confidence level of 0.95; when measuring concentrations below the MPC - the limits of the permissible absolute measurement error should be +/- 0.25 MPC in mg / cubic meter. m at a confidence level of 0.95, p. 5.4 GOST 12.1.005-88 (Amendment N1 from 2000)
• in the process of air control in the working area, with significant temperature changes environment and atmospheric pressure, it is necessary to recalculate the measured values ​​with a corresponding readjustment of the alarm thresholds of the gas analyzer.

Technical criteria

1. Compliance technical characteristics device operating conditions at a specific facility:

• execution (explosion-proof for categorized objects, or general industrial);
• temperature Range;
• if necessary, control in hard-to-reach places (wells, tanks, etc.) - a built-in pump or " remote sensor By the way, practice shows that the built-in stimulus is more reliable during operation, because eliminates malfunctions associated with a broken cable between the sensors and the device, the possibility of failure of sensors due to contact with liquids in containers, wells, etc., but here, as they say, there is no general opinion on taste and color.

By the way, when studying technical parameters devices do not trust the data given in advertising, and even in the instruction manual for the product, because during the certification of devices in the State Standard, some parameters of the devices are not confirmed and there are facts when, for example, the operating temperature range of the device is indicated in the operating manual from -40 to 50 ° С, and in the appendix to the description of the type of measuring instruments from -20 to 40 ° С. This is especially often the case with imported devices. Therefore, it is better to request an Appendix to the Certificate of Type Approval of Measuring Instruments. For flammable gases and vapors alarms, it is imperative to make sure that the substances present at your facility are in the list of substances monitored by this device, it is indicated in the technical specification for the product or in the appendix to the Type Certificate of measuring instruments. If the required substance is not on the list, which happens quite often, then it is best to ask the manufacturer for written confirmation of the possibility of using this device to control the required substance. If, instead of an official response, you are redirected to an advertisement or a website, think carefully before purchasing the device, because neither is an official document.

2. Make sure that you receive the device, certified by the State Standard, and the manufacturer has the right to supply the device with a verification period of no more than half of the calibration interval. The delivery set of the device should include a verification procedure, which will allow you to verify it in the regional divisions of Gosstandart (CSM) or other organizations accredited for the right to carry out state verification.

Price criteria

1. Check with the supplier the price for the device in the configuration that you need (charging and feeding devices, elements for sampling - a flow rate driver if it is not built into the device, samplers, a sample transport line, all kinds of devices for reading information in the presence of non-volatile device memory, etc.). Consider the cost of delivery and state verification, because some manufacturers do it for a fee.

2. Calculate the cost of maintenance and repair. To determine the cost of repair, it is necessary to request the cost of the sensitive elements of the devices, since most often they are the ones that fail, and at the same time, make sure that they can be purchased (some manufacturers use imported sensitive elements and do not always supply them to users, sending them to the import manufacturer or its dealers).

Compliance with the above criteria will allow you to maximize the safety of your personnel, eliminate the possibility of problems with Rostekhnadzor. and also competently motivate your own management the choice you made, which is also important.

Head of the Analytical Sector
FSUE “SPA“ Analitpribor ”A.P. Sitnikov
[email protected]

Modern industry, saturated with all kinds of high-tech solutions, increasingly needs the most precise control. This is especially true for such cornerstone industries as: energy, defense and oil and gas complexes, transport industry, where the priority is.

To accomplish this task, various controllers are used, one of the types of which are gas analyzers(gas detectors). These devices are designed to measure the concentration of certain components in gas mixtures. Moreover, one class of devices ensures the detection of explosive vapors leaks before their content reaches the maximum permissible level. The other detects possible leaks of toxic gases or liquid vapors. In both cases, the analyzer gives a signal (light and sound), warning of the danger.

Design and classification of gas analyzers

Regardless of the type gas analyzer classification consists of the following main elements:
- primary transducer (sensitivity sensor), which, using various measurement methods, converts the gas concentration into a measured electrical signal;
- measuring-showing module, which processes the received signal, compares it with certain threshold values ​​and then outputs the result to a digital indicator;
- power supply unit and protective case.

Distinguish between devices by field of application and installation method. It depends on the operating conditions. So, in addition to general industrial use, the devices can be used in the field of increased explosiveness (drilling of oil and gas wells) and in special conditions(mine, sea). Based on this, gas analyzers are stationary and portable (portable).

The former conduct constant automatic monitoring of the concentration of gases (vapors) and, if a predetermined threshold is exceeded, they give all kinds of signals, and can also turn on ventilation and other security systems themselves. The latter, above all, provide personal safety. They continuously measure the content of gas mixtures directly at the location of the employee. The devices are mounted on overalls or on a protective helmet.

Types of gas analyzers and the most interesting models

The main difference between types of gas analyzers- Method of measurement. According to this characteristic, all devices are divided into optical, thermocatalytic, electrochemical and semiconductor devices.

Thermocatalytic or thermochemical

One of the cheapest types of analyzers... The principle of operation is the oxidation of hydrocarbons on a catalytically active element. Gas concentration is measured in proportion to the heat generated in relation to the hydrocarbon content. It is not distinguished by the best reliability, does not withstand overloads, has low sensitivity, as well as a number of others serious shortcomings... Nevertheless, it is still used in industry, although it is obsolete.

One of the most popular representatives of this type- universal microprocessor-based gas analyzer STM-30M Russian production(FSUE SPO Analitpribor). It is used for continuous automatic control of pre-explosive concentrations of combustible gases (mixtures). It is mainly used in the oil and gas sector. Able to recognize up to 140 flammable substances. Operates in the temperature range from -60 to +180 ºС.

Electrochemical

A fairly common type of analyzers. Carries out measurement by passing electric current through electrolyte solutions in contact with the analyzed gas. Unfortunately, just like thermochemical devices, they have a short service life. But in good condition they are used to work with a wide range of gases. Capable of measuring ultra-low concentrations. Primary purpose - excellent detection of toxic gas leaks.

A high-quality gas detector of this type is offered by another domestic company "Eris". The model is used to continuously detect hazardous concentrations of toxic gases, oxygen gas or vapors. It is used to control the gas content of the air in the working area.

Semiconductor

These are versatile devices. They work on the principle of changing the surface resistance of a semiconductor material as a result of exposure to gas. As a meter, their use is ineffective, since the measurement error is high. But as an excellent leak detector for flammable or toxic gas mixtures, a semiconductor device is irreplaceable.

Very reliable hydrogen sulfide gas analyzer NTMOS Det-tronics company (USA). It is an automatic continuous air monitoring device. Has very high performance characteristics... It can operate in the temperature range from -40 to +60 ºС.

Optical (infrared, absorption)

The most expensive type of analyzers. Has high sensitivity and measurement accuracy. The principle of operation is based on the ability of gas molecules to selectively absorb infrared radiation... These devices operate in a wide range of gas concentrations. They can work with overloads. Ideal for detecting explosive and combustible gas leaks.

The most popular model is (China). High accuracy measurements are provided by using innovative technologies... The error in the operation of the device is 1%.

By the way, today you can find more and more universal, multifunctional devices. They combine all four measurement methods. For example, the apparatus Sigma-03 Russian company Prompribor-R.