Device for preparation of calibration gas mixtures

 

The invention relates to the field of analytical instrumentation, in particular, to devices for preparation of calibration gas mixtures used in the calibration and calibration of gas analyzers. The technical result is to create a device for the preparation of calibration gas mixtures using only one cylinder as the source of the original substance without the use of high-pressure cylinders with gas diluent. Device for preparation of calibration gas mixtures contains a source of calibration gas or mixture of gases in the form of a cylinder of a high pressure mixer gases and dilution of the gas mixture after the mixer additional flow of the diluent gas. In the device the gas mixer is made in the form of a tank having two channels for supplying mixed gases, one of which is connected through a controlled shut-off valve with a source of calibration gas or mixture of gases, and the second channel is connected to atmospheric air, the channel to output a mixture of gases, which is connected to the system dilution of the gas mixture and which has a detector for monitoring the content of the calibration gas and the pump flow rate, and device introduced additional detector deltoidea to the field of analytical instrumentation, in particular to devices for preparation of calibration gas mixtures. It can be used in the calibration and verification of gas analyzers, chromatographs and other equipment for gas analysis.

Known sources of test gas mixtures are high-pressure cylinders, up to 40 litres, filled with mixed gas of a particular composition at pressures up to 100 atmospheres and above (see Control of chemical and biological environmental parameters. Encyclopedia Of "Econometrics". Series under the guidance of associate Professor, Saint-Petersburg, 1998, S. 587-602). Such cylinders are subject to the Rules and the device of the vessels working under pressure, requiring certain conditions of operation, transport and storage. Often the "Rules" don't allow the use of bags in the shops and other categorized premises, which creates additional difficulties. In addition, large cylinders are heavy and difficult to transport.

For calibration of the devices within the operating range of the measurement is used several mixtures with different concentrations. This requires either the use of multiple cylinders or expensive systems dilution.

Finally, the composition povero what s this phenomenon mixture with a low content of test gas and mixtures containing corrosive gases.

A device for preparation of calibration gas mixtures containing a source of pure test gas in the form of a cylinder of high pressure and one or more sources of the diluent gas, such as filtered air, mixer gases and dilution of the gas mixture after the mixer additional flow of the diluent gas (see, for example, ABT. mon. THE USSR 1546945, G 01 D 11/035, 1990).

In the known device as sources of the diluent gas is also used in high-pressure cylinders. This, as described above, requires certain security measures and expensive procedure of verification.

The objective of the invention was to create a device for the preparation of calibration gas mixtures, allowing to obtain calibration mixtures in a wide range of concentrations, using only one cylinder as the source gas, without the use of high-pressure cylinders with gas diluent.

This task is solved in that the device for preparation of calibration gas mixtures containing a source of calibration gas or mixture of gases in the form of a cylinder of high pressure, the source of the diluent gas, the gas mixer and the system is meniu mixer gases made in the form of tanks, having two channels for supplying mixed gases, one of which is connected through a controlled shut-off valve with a source of calibration gas or mixture of gases, and the second channel is connected to atmospheric air, and the channel to output a mixture of gases, which is connected to the system dilution of the gas mixture and which has consistently set the detector to control the content of the test gas in the output mix and stimulate consumption.

Another distinctive feature of the proposed device is that it introduced the detector to control the content of the test gas in the gas mixer. With this purpose in a preferred embodiment of the device the gas mixer is equipped with a channel for the selection of the gas mixture from the mixer and channel to return this part of the gas mixture in the mixer to form a closed gas circuit, which has the additional consumption booster and detector to control the content of the calibration gas.

Another distinctive feature of the proposed device is that the system dilution of the gas mixture after the mixer contains the microcompressor, the input of which is connected to atmospheric air, and the output is connected to the channel for the output gas mixture from the mixer.

Among the differences device is the ml detector for monitoring the content of the test gas in the gas mixer and the output of the mixture, and control outputs connected to the actuator controlled shut-off valve and actuator of the microcompressor.

Due to the above implementation of the proposed device not only eliminates the need to use high-pressure cylinders with gas diluent, but also provides control of the concentration of the calibration mixture during its preparation in a wide range of calibration gas dilution.

The invention is illustrated by the drawing, which shows a schematic diagram of the proposed device.

The proposed device comprises a source 1 calibration gas or gas mixture of a certain composition in the form of a cylinder of high pressure with regulator 2 pressure and mixer 3 gases, made in the form of containers made of inert relative to the mixed gas of the material, for example glass. The mixer 3 is connected to the calibration gas source 1 through channel 4 and controlled shut-off valve 5 is supplied with a drive 6, for example an electromagnetic actuator. The mixer 3 through the channel 7 for the supply of the diluent gas and the filter 8 is connected with the atmospheric air serving in the present invention as the diluent gas.

The filter 8 is designed for ogistical 3 is connected to the channel 9 to the output of the gas mixture, in which consistently set the detector 10 to control the content of the test gas in the air and booster 11 consumption. Channel 9 for the output gas mixture is supplied by a dilution system, which contains the microcompressor 12, whose input is through the filter 13 is connected to atmospheric air, and the output is connected to channel 9 for the output gas mixture from the mixer 3. The mixer 3 is supplied by a channel 14 for selecting the part of the mixture from the mixer 3 and the channel 15 to return this part of the mixture in the mixer 3, forming a closed gas circuit 16, in which is installed an additional detector 17 to control the content of the test gas in the mixer 3 and additional booster 18 consumption.

The device is equipped with a microprocessor unit 19 of the control inputs 20 and 21 which are connected to the outputs of the detectors 10 and 17 for controlling the concentration of test gas in the output mixture and the mixer 3, and the outputs 22 and 23 connected to the drive microcompressor 12 and the actuator 6 is controlled shut-off valve 5.

The choice of the type of detectors 10 and 17 for controlling the concentration of the calibration gas is determined by the composition of the calibration mixture. For example, if the calibration mixture is a mixture of methane with air, the detectors 10 and 17 can be used detector is the Braz. Before you begin the device includes boosters 11 and 18 of flow, and connected in series with them the detectors 10 and 17. After the release of the detectors 10 and 17 on the stationary mode of operation of the microprocessor unit 19 controls within the given time the program generates a control signal for opening the shut-off valve 5. Calibration gas or mixture of gases from the cylinder 1 through the open shut-off valve 5 is collected in the tank 3 where it is mixed with inside air. Part of this mixture through the channels 14 and 15 under the action of the pump 18 flow circulates in a closed gas circuit through the detector 17. After concentration of the calibration gas in the tank 3 reaches the set value and the detector 17 generates a corresponding signal to the control input 21 of the microprocessor unit 19 controls, shut-off valve 5 is closed for traffic and capacity 3 starts to operate as a source of calibration gas mixtures. Calibration gas mixture taken from the tank 3 through the channel 9, is diluted by atmospheric air, purified by the filter 13 and discharged with the microcompressor 12. Atmospheric pressure in the tank 3 is supported by atmospheric air entering the tank 3 through the channel 7 through the filter 8. Conceded verified on the device. The signal coming from the detector 10, is fed to microprocessor 19 controls, which compares it with the specified value and maintains the setpoint signal corresponding to a desired concentration by regulating the voltage at the microcompressor 12. Concentration calibration gas mixture at the output of the detector may vary within wide limits, ranging from the initial concentration of the calibration gas in the tank 3 to any lower concentration, as measured by the detector with the required accuracy. When the microprocessor unit 19 of the control is unable to maintain a given concentration that occurs depending on the rate of loss of the test gas from the tank sooner or later, again open the stop valve 5 and the process is repeated from the beginning.

Claims

1. Device for preparation of calibration gas mixtures containing a source of calibration gas or mixture of gases in the form of a cylinder of high pressure, the source of the diluent gas mixer gas and dilution gas mixture after the mixer additional flow of the diluent gas, wherein the gas mixer is made in the form of a tank having two capouano gas or mixture of gases, and the second channel is connected to atmospheric air, and the channel to output a mixture of gases, which is connected to the system dilution of the gas mixture and which has consistently set the detector to control the content of the test gas in the air and stimulate consumption.

2. The device under item 1, characterized in that it introduced a detector for monitoring the calibration gas in the gas mixer.

3. The device according to p. 2, characterized in that the gas mixer is equipped with a channel for the selection of the gas mixture from the mixer and channel to return this part to the mixer forming a closed path in which you installed the detector to control the content of the test gas in the mixer and additional consumption booster.

4. The device under item 1, or 2, or 3, characterized in that the system dilution of the gas mixture after the mixer contains the microcompressor, the input of which is connected to atmospheric air, and the output is connected to the channel for the output gas mixture from the mixer.

5. The device according to p. 4, characterized in that it introduced a microprocessor control unit, the inputs of which are connected to the outputs of the detectors to control the content of the test gas in the mixer and in the channel to output a mixture of gases after system razbavleniya.

 

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Device for sampling // 2107289
The invention relates to a device for sampling a gaseous and liquid state, in particular, highly permissive qualitative and quantitative microanalysis for gas and liquid chromatography and mass spectrometry

FIELD: chemical technology.

SUBSTANCE: invention relates to a method for synthesis of ester perfluorinated derivative by using a chemical reaction. This reaction represents the fluorination reaction of the parent compound as a raw, the reaction of chemical conversion of fragment of ester perfluorinated derivative to yield another ester perfluorinated derivative or the interaction reaction of carboxylic acid with alcohol under condition that at least one or reagent, i. e. carboxylic acid or alcohol, represents a perfluorinated compound wherein indicated perfluorinated derivative of ester represents a compound comprising a fragment of the formula (1):

with a boiling point 400°C, not above. The reaction time for carrying out abovementioned chemical reaction is sufficient to provide the required yield of ester perfluorinated derivative and wherein this yield of ester perfluorinated compound is determined by the gas chromatography method by using a nonpolar column. Also, invention relates to a method for pyrolysis of ester perfluorinated derivative with a boiling point 400°C, not above, to yield the dissociation product wherein this product represents a derivative of acyl fluoride or ketone and wherein pyrolysis time is sufficient to provide the required degree of conversion of ester perfluorinated derivative and wherein the indicated conversion degree of ester perfluorinated derivative is determined by gas chromatography method by using a nonpolar column. Also, invention relates to a method for analysis of ester perfluorinated derivative with a boiling point 400°C, not above, that involves analysis of ester perfluorinated derivative in a sample containing ester perfluorinated derivative by gas chromatography method by using a nonpolar column wherein ester perfluorinated derivative represents compound comprising a fragment of above given formula (1).

EFFECT: improved method of synthesis.

8 cl, 1 dwg, 2 ex

FIELD: instrument engineering.

SUBSTANCE: device for generating flow of vapor-gas mixture with preset concentration of vapor has vessel partially filled with fluid, second vessel provided with branch pipes for supply and removal of gas, and vapors of fluid pipeline-leak. One of vessels is connected with gas discharge forcer; fluid vapors pipeline-leak connects both vessels. Vessel, partially filled with fluid, is mounted inside second vessel. Pipeline-line, connecting both vessels, is totally placed inside second vessel. Device is also provided with additional discharge forcer for adjusting concentration of fluid vapor in second vessel. Granulated filler is introduced into vessel partially filled with fluid. Device is also provided with gas analyzer for providing gas concentration in space of second vessel.

EFFECT: higher precision of keeping of preset concentration of vapor; improved efficiency of vapor concentration control and adjustment.

FIELD: instrument engineering.

SUBSTANCE: invention is designed for calibrating gas analyser detectors, according to which there prepared is calibration substance solution with concentration A=By/k (%) as per Henry constant value k (mg/m %) at calibration temperature and as per the specified value of calibration substance mass concentration in calibration steam/gas mixture By (mg/m). After the solution has been introduced into the vessel in quantity enough for fully saturated equilibrium calibration steam/gas mixture to appear above the solution surface, the sensor calibration is carried out by means of mixture; at that, mixture concentration is changed by means of direct proportional change of solution concentration by diluting concentrated reference solution of calibration substance with analytical accuracy up to the specified concentration value A (%). There also proposed is the device for realising this method, which includes a solution point for preparing calibration solution with analytical accuracy, vessel with thermostatic device for obtaining steam/gas mixture with constant concentration corresponding to Henry law; at that, solution point includes graduated dose metre, graduated diluter, mixer with a reducer, capacity with solvent, and reference container with reference solution, which is stabilised with a gate valve meant for multiple use of container, and vessel with thermostatic device consists of thermometre and heat-insulating cover plate with an inlet branch pipe containing a normally closed return valve and a pusher for valve opening.

EFFECT: decrease of calibration substance losses; accuracy and reproducibility of metrological performance, and meeting requirements of industrial and ecological safety.

6 cl, 2 dwg

FIELD: physics.

SUBSTANCE: vapour-gas mixture source has a mixer which has connecting pieces for inlet and outlet of the vapour-gas mixture. The vapour-gas mixture source also has a diffusion pipe filled with working fluid and an auxiliary pipe designed for filling the diffusion pipe with working fluid. Part of the diffusion pipe is filled with substance which retains the working fluid. The level of working fluid in the auxiliary pipe is lower than the level of substance in the diffusion pipe. The substance which retains the working fluid used can be sand, granular material with particle size between 10 and 10000 mcm, porous substances, e.g. ceramic metal etc.

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11 cl, 2 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to laboratory methods of analysis and deals with method of quantitative determination of manganese, lead and nickel in bile by method of atomic-absorption analysis with atomisation in flame. Essence of method lies in the following: sampling of bile is carried out during duodenal probing, after that it is frozen, and unfrozen at room temperature, homogenisation of bile by mixing being performed already at partial soft unfreezing. After that, sampling of homogenised bile is carried out for preparation for analysis, concentrated nitric acid is introduced into it with volume ratio 1:1, mixture is kept at room temperature, then heated and further mixture is kept for not less than 2.5 hours at room temperature. In order to obtain analyte, to obtained mixture added is concentrated hydrogen peroxide in volume ratio 1:1 to volume of bile sample volume, analyte is heated, after that cooled to room temperature. After that by method of atomic-absorption spectrometry, using graduated diagram, quantitative content of particular type of metal: manganese, lead and nickel is determined in analyte.

EFFECT: invention allows increasing accuracy of quantitative determination of manganese, lead and nickel in bile.

6 tb

FIELD: engines and pumps.

SUBSTANCE: proposed method is based on application of simplified model of intake of admixtures into cabin which allows for only oil decomposition products in gas turbine engine. Major portion of air samples, 95-97%, required for identification and quantitative determination of oil decomposition products, is sampled on surface from device simulating oil decomposition conditions including air temperature and pressure at point of sampling from engine compressor, and oil stay time in hot zone.

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1 cl, 1 ex, 1 tbl, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to analytical chemistry, particularly to methods of determining benzoic acid, and describes a method for quantitative determination of benzoic acid from a methyl derivative thereof - methyl ether in aqueous matrices with determination sensitivity of 5.010-5 mg/cm3 with determination error of not more than 25%. The method is characterised by that quantitative determination of benzoic acid is carried out using a chromatographic method with flame-ionisation detection and includes the following steps: extraction concentration of an analyte with benzene in water samples acidified with 25% sulphuric acid solution to pH 1-3 while adding sodium chloride until a saturated solution is obtained, conducting a benzoic acid methylation reaction with diazomethane to obtain a derivative - methyl ether of benzoic acid and determining the formed methyl ether of benzoic acid by a chromatographic method with flame-ionisation detection.

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1 ex, 3 tbl

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