GOST 9853.3-96
GOST 9853.3−96 Titan spongy. Methods for determination of carbon
GOST 9853.3−96
Group B59
INTERSTATE STANDARD
TITANIUM SPONGE
Methods for determination of carbon
Sponge titanium. Methods for determination of carbon
ISS 77.120*
AXTU 1709
____________________
* In the index «National standards» in 2007.
ISS 77.120 and
Date of introduction 2000−07−01
Preface
1 DEVELOPED by the Interstate technical Committee for standardization MTK 105, Ukrainian research and design Institute of titanium
SUBMITTED to the State Committee of Ukraine for standardization, Metrology and certification
2 ADOPTED by the Interstate Council for standardization, Metrology and certification (Protocol No. 9 dated April 12, 1996)
The adoption voted:
| The name of the state |
The name of the national authority for standardization |
| The Republic Of Azerbaijan |
Azgosstandart |
| The Republic Of Belarus | Gosstandart Of Belarus |
| The Republic Of Kazakhstan |
Gosstandart Of The Republic Of Kazakhstan |
| Russian Federation |
Gosstandart Of Russia |
| Turkmenistan |
The main state inspection of Turkmenistan |
| Ukraine |
Gosstandart Of Ukraine |
3 Resolution of the State Committee of the Russian Federation for standardization and Metrology dated 19 October 1999 No. 353-St inter-state standard GOST 9853.3−96 introduced directly as state standard of the Russian Federation from July 1, 2000.
4 REPLACE GOST 9853.3−86
1 Scope
This standard specifies methods for the determination of carbon in sponge titanium according to GOST 17746: chromatographic method (with a mass fraction of carbon from 0.001% to 0.15%), by a gas-volume method (when the mass fraction of carbon from 0.01% to 0.15%), the coulometric method (when the mass fraction of carbon from 0.003% to 0.2%) and method of induction heating (when the mass fraction of carbon from 0.003% to 0.2%).
Chromatographic method for determination of carbon in spongy titanium based on the combustion of titanium in flowing oxygen, followed by purification of the resulting gas mixture from interfering impurities and chromatographic separation of carbon dioxide and oxygen by using the solid sorbent. For measuring the amount of carbon dioxide using a detector that registers the thermal conductivity of the analyzed mixture and inert gas, in conjunction with a recording potentiometer.
By a gas-volume method based on the combustion of a sample of titanium in flowing oxygen at a temperature of 1523−1573 To the subsequent absorption of the formed carbon dioxide by potassium hydroxide solution. The carbon content is determined by difference between the initial volume and the volume of gases obtained after absorption of carbon dioxide by potassium hydroxide solution.
Coulometric method is based on the combustion of a sample of titanium in flowing oxygen with the formation of carbon dioxide, the content of which is determined by coulometric method.
Method of induction heating based on the combustion of a sample of titanium in flowing oxygen with the formation of carbon dioxide, the content of which is determined using a sensor absorbing radiation in the infrared region of the spectrum.
2 Normative references
The present standard features references to the following standards:
GOST 8.315−97 State system for ensuring the uniformity of measurements. The standard samples. The main provisions, the order of development, certification, approval, registration and application
GOST 450−77 Calcium chloride. Specifications
GOST 859−78* Copper. Brand
________________
* On the territory of the Russian Federation GOST 859−2001. Here and hereinafter. — Note the manufacturer’s database.
GOST 3776−78 Chromium (VI) oxide. Specifications
GOST 4140−74 Strontium chloride 6-water. Specifications
GOST 4199−76 Sodium tetraborate 10-aqueous. Specifications
GOST 4204−77 sulfuric Acid. Specifications
GOST 4207−75 Potassium ferrocyanide 3-aqueous. Specifications
GOST 4232−74 Potassium iodide. Specifications
GOST 4233−77 Sodium chloride. Specifications
GOST 4234−77 Potassium chloride. Specifications
GOST 4470−79 of Manganese (IV) oxide. Specifications
GOST 5583−78 (ISO 2046−73) Oxygen gas technical and medical. Specifications
GOST 8074−82 Microscopes tool. The types, basic parameters and dimensions. Technical requirements
GOST 9147−80 Glassware and equipment lab porcelain. Specifications
GOST 9293−74 (ISO 2435−73) Nitrogen gaseous and liquid. Specifications
GOST 10727−91 unidirectional glass Threads. Specifications
GOST 13045−81 Rotameters. General specifications
GOST 16539−79 Copper (II) oxide. Specifications
GOST 17746−96 spongy Titanium. Specifications
GOST 18143−72 high-alloy Wire, corrosion-resistant and heat-resistant steel. Specifications
GOST 18300−87 ethyl rectified technical. Specifications
GOST 20490−75 Potassium permanganate. Specifications
GOST 23780−96 spongy Titanium. Methods of sampling and sample preparation
GOST 24363−80 Potassium hydroxide. Specifications
GOST 25086−87 non-ferrous metals and their alloys. General requirements for methods of analysis
3 General requirements
3.1 General requirements for methods of analysis GOST 25086.
3.2 Selection and preparation of samples is carried out according to GOST 23780.
3.3 Mass fraction of carbon is determined in two batches.
4 Chromatographic method
4.1 measuring instruments and auxiliary devices
Setup for determination of carbon (figure 1) consists of the following elements: oxygen cylinder 1, provided with a pressure reducing valve; choke 2; resistance furnaces 3, providing temperature not lower than 1573 K; thermocouple platinum-rhodium 4; potentiometer electronic 5 type KSP-4, with a view to regulating set temperature with an accuracy of ±5%; unglazed porcelain tubes 6 and 6' in length 750 mm, the inner diameter of 18−20 mm (the ends of the tubes should protrude out of the oven not less than 160 mm on each side, and before use the tube needs to be calcined at a temperature of 1573 K over the entire length); boats porcelain 7 (before use, the boat needs to be calcined in a current of oxygen at a temperature of 1573 K for hours, calcined boats stored in a desiccator, ground joint lid of the desiccator is not smeared with grease); transformer 8 type RNO-250−5; bells Tishchenko 9filled with angerona and Astarita; tube U-shaped quartz 10filled with zeolite 5A; glass porcelain 11; tube U-shaped metallic 12; thermos 13; gorkaltseva tube 14filled with potassium iodide with cotton; three-way tap 15; a hub 16, is filled with a zeolite 5A; tubular furnace 17type MA, providing the temperature not lower than 800 K; laboratory autotransformer 18type Latr 1M; chromatograph 19 (threshold sensitivity of the detector, the thermal conductivity does not exceed 1·10mg/cm
when used as a carrier gas helium, 1·10
mg cm
— when using nitrogen), including: tap-dispenser 20, a chromatographic column 21, a recording potentiometer 23 and katharometer 22; helium tanks 24equipped with a reducing valve.
Figure 1
Microscope readout type BCH-2 according to GOST 8074.
Stopwatch, class 3, graduation of the second scale 0.2 s according to the current normative document.
The hook is made of heat-resistant low-carbon wire according to GOST 18143 length of 600 mm, a diameter of 3−5 mm.
Tube PVC according to the current normative document.
Tube vacuum according to the current normative document.
Oxygen gas according to GOST 5583.
Helium gas purified grade B according to the current normative document.
Potassium iodide (potassium iodide) according to GOST 4232.
Magnesium perchlorate (anhydro) according to the current normative document.
Askari according to the current normative document.
Liquid nitrogen according to GOST 9293.
Zeolite type 5A (CAA).
Ethanol (ethyl alcohol) rectified technical GOST 18300.
Polisorb-1 (fraction 0.25−0.5 mm) according to the current normative document.
The beach — the powdery copper oxide according to GOST 16539.
Copper oxide pre-calcined in flowing oxygen at a temperature of 1073 K for 6 h. as a smoother can be applied to other materials, provides the maximum extraction of carbon from the sample analyzed. Mass fraction of carbon in the flux should not exceed 0,002%; it allowed the burning of the sample without flux under the condition of complete extraction of carbon.
State standard samples according to GOST 8.315.
4.2 preparation for measurement
4.2.1 Sample purified from possible contamination. For this purpose it is washed with ethanol at the rate of 10 cmper 1 g of the sample, is then dried to remove the ethanol. If necessary, clean the analysed sample stored in a glass container.
4.2.2 Before starting, installation of the lead in working condition: chromatographic column 21 length 3 m filled polycarbon-1; hub 16 (U-shaped tube length of 180 mm, inner diameter 3 mm) filled with zeolite 5A (0.3−0.4 g); a porcelain tube 6, which serves to clean oxygen fill quartz nozzle; the flask Tishchenko 9 fill respectively the perchlorate of magnesium and Astarita; a U-shaped tube 10 is filled with zeolite 5A and is placed in a vessel 11 with ice; A U-shaped tube 12is placed in a vessel 13 above the liquid nitrogen; gorkaltseva the tube 14 is filled with potassium iodide with cotton wool.
Then all of the unit tightly connect with each other butt with a vacuum or PVC tubes.
The connection of chromatograph and electric furnaces to a network and output them to the operating mode performed when the combustion 1523−1573 K; temperature concentration of 273 K; the desorption temperature of 753 K; the temperature for the chromatographic separation of 373 K; the current bridge detector (chromatograph «Color-4») 250 mA; consumption of oxygen and helium (mix) — 60 cm/min.
After the installation is assembled, check it for leaks.
4.2.3 To carry out control experience tap-dispenser 20 is installed in position 1. Using a three-way tap 15 connects the hub 16 with the analytical part of the installation. Then submerge the hub in a vessel with ice 11. Prepared the boat with the flux is placed in the most heated part of the tube, and concentrate carbon dioxide for 10 min.
After concentrating disconnect the hub from the analytical part of the unit and set it in the oven 17, heated to a temperature of 753 K. Crane-dispenser switch in position 2. Include the potentiometer 23.
After registering peaks of residual oxygen and carbon dioxide potentiometer off.
4.3 measurements
The faucet spout is installed in position 1. Using a three-way tap connecting the analytical part of the installation with the hub, then the hub is immersed in a vessel with ice.
At the bottom of the boat is placed a portion of the titanium with a mass of 0.5−1.0 g, cover with a layer of flux — copper oxide in a ratio of 1:4 and set in the most heated portion of the porcelain tube. (Burning titanium can be carried out without flux, but in this case it is necessary to carry out the process at temperatures above 1573 K).
Further analysis is carried out in the same order as specified
4.4 Processing of measurement results
Mass fraction of carbon , % calculated according to the formula
where is the peak area corresponding to the content of carbon dioxide in the sample, mm
;
the peak area corresponding to the content of carbon dioxide in a control experiment, mm
;
— mass fraction of carbon in the standard sample, %;
— weight of standard sample, g;
the peak area corresponding to the content of carbon dioxide in the standard sample, mm
;
— the weight of the portion of the sample,
4.5 Permissible error of measurement
4.5.1 the discrepancy between the measurement results and analysis results (at a confidence probability =0,95) shall not exceed the values given in table 1.
Table 1
| Mass fraction of carbon | The permissible discrepancy between the results of the parallel measurements |
The permissible discrepancy between the results of the analysis | The margin of error of measurement |
| From to 0,0010 0,0030 incl. |
0,0005 | 0,0010 | 0,0008 |
| SV. 0,003 «to 0,006 « |
0,001 | 0,002 | 0,002 |
| «0,006» 0,010 « |
0,002 | 0,003 | 0,002 |
| «0,010» 0,020 « |
0,003 | 0,004 | 0,003 |
| «0,020» 0,030 « |
0,004 | 0,005 | 0,004 |
| «0,030» 0,040 « |
0,005 | 0,006 | 0,005 |
| «0,040» 0,050 « |
0,007 | 0,008 | 0,006 |
| «0,050» 0,150 « |
0,014 | 0,020 | 0,016 |
4.5.2 accuracy Control of the results of the analysis carried out according to standard sample in accordance with GOST 25086.
Allowed to monitor the accuracy of analysis results by the method of additives in accordance with GOST 25086.
5 by a gas-volume method
5.1 measuring instruments and auxiliary devices
Setup for determination of carbon (figure 2) consists of an oxygen cylinder 1, provided with a pressure reducing valve; Tishchenko flask 2containing a solution of potassium permanganate mass concentration 40 g/lsolution of potassium hydroxide mass concentration of 400 g/DM
; Tishchenko flask 3containing sulfuric acid; U-shaped tube 4filled in the first half (in the direction of oxygen) soda lime and the second with chloride of calcium; U-shaped tube 5, filled
with Astarita and
calcium chloride; an electric furnace 6 with silicafume heaters and voltage regulator 7; thermocouple platinum-rhodium 8; a controller 9; the unglazed porcelain tube 10with a length of 750 mm, an inner diameter of 18−20 mm (the ends of the tube should protrude out of the oven in less than 160 mm on each side, and before use the tube needs to be calcined at a temperature of 1573 K over the entire length); the flask 11containing a chrome compound; tube 12, filled with glass wool; bottles 13containing a solution of potassium iodide mass concentration of 100 g/DM
; the detector GOU, including refrigerator coil 14, three-way valve 15that connects the gas-measuring burette 16 with a refrigerator and an absorption vessel 17; single tap 18, linking the measuring burette with the atmosphere.
Figure 2
Vessel for the absorption of carbon dioxide is equipped with a slide valve floats, which close the sink when it is filled with alkali solution. The absorber is connected with a cylindrical vessel during the filling of the absorber of a gas mixture is pumped alkali solution. For pumping the gas mixture is equalization flask 19 with a capacity of 600−700 cm, filled with a solution of sodium chloride.
Gas-measuring burette-audiometer 20 with a scale of up to 0.25% carbon is a narrow cylindrical vessel, enlarged in upper part, with a capacity of 250 cm. Burette has double walls, the space between which is filled with water, so the environment has little effect on the temperature of the gas in the burette. At the top of the burette fortified thermometer to measure the temperature of the gas, there is a hollow float which, when filling the burette rises and locks the top hole. The narrow part of the burette is attached a sliding scale for volume measurement of gases. The scale division corresponds directly to the carbon content in 1 g of the test substance. Burettes are calibrated at a temperature of 289 K and a pressure of 1·10
PA, therefore, for other conditions enter a correction for temperature and atmospheric pressure. Table of correction factors given in the operating instructions of audiometry. Measuring burette must be rinsed with chromic mixture 1−2 times a month.
Pumps porcelain N 2 according to GOST 9147 before applying calcined in flowing oxygen at a temperature of 1573 K for 1 h. Calcined boats stored in a desiccator. Sections of the lid of the desiccator should not be lubricated.
The hook is made of heat-resistant low-carbon wire according to GOST 18143 diameter of 3−5 mm, length 600 mm.
Calcium chloride fused according to GOST 450.
Ethanol (ethyl alcohol) rectified technical GOST 18300.
Chromium (IV) oxide (chromic anhydride) according to GOST 3776.
The lime soda.
Askari according to the current normative document.
Oxygen gas according to GOST 5583.
Chrome mix: 85 g of chromium oxide (VI) was dissolved in 120 cmof distilled water, the solution was poured in small portions with stirring, 500 cm
of concentrated sulfuric acid; the solution was stored in a closed flask.
Potassium hydroxide according to GOST 24363, solution mass concentration of 400 g/DM.
Potassium permanganate (potassium permanganate) according to GOST 20490, solution mass concentration of 40 g/DM: 20 g of potassium permanganate dissolved in 500 cm
of a solution of potassium hydroxide.
Methyl orange, according to existing normative document, solution mass concentration of 1 g/DM.
Sulfuric acid according to GOST 4204.
Sodium chloride (sodium chloride) according to GOST 4233, solution mass concentration of 260 g/DM: 260 g of sodium chloride dissolved in 1000 cm
of water with the addition of 5 cm
of sulphuric acid and 2−3 drops of methyl orange.
Potassium iodide (potassium iodide) according to GOST 4232, solution mass concentration of 160 g/DM.
The beach — the powdery copper oxide according to GOST 16539. The copper oxide must first be calcined in flowing oxygen at a temperature of 1073 K for 6 h.
As a smoother can be applied to other materials, provides the maximum extraction of carbon from the sample analyzed. Mass fraction of carbon in the flux should not exceed 0,002%; it allowed the burning of the sample without flux under the condition of complete extraction of carbon.
State standard samples according to GOST 8.315.
5.2 preparation for measurement
5.2.1 Sample purified from possible contamination. For this purpose it is washed with ethanol in a volume 10 cmper 1 g of the sample, is then dried to remove the ethanol. If necessary, clean the analysed sample stored in a glass container.
5.2.2 Preparing the installation to work as follows. The ends of the porcelain tubes closed with rubber stoppers embedded with glass tubes. The rubber tube on the gas outlet of a furnace is not burned, the inner end surface of the tube is closed with asbestos gasket.
The absorption vessel is filled with a solution of potassium hydroxide, and the surge flask are poured 400−450 cmof a solution of sodium chloride.
Change the red color of methyl orange to yellow indicates the penetration of the burette with the alkali solution from the absorption vessel. In this case, the liquid in the burette must be replaced fresh. After each fill surge bottle with fresh liquid it is recommended to conduct one or two pre-burning batches of titanium to saturate the liquid with carbon dioxide, otherwise determining the content of carbon after filling equalization flask with fresh liquid, new results may be understated.
One end of the porcelain tube connecting rubber hose of a cleaning flask with a balloon containing oxygen, and the second unit go. After that, the installation check for leaks at the operating temperature of the furnace. For this Central three-way faucet 15 put in a position that divide the burette, absorption vessel, and a refrigerator. Opening the faucet 18, the surge raised the flask, the burette is filled with fluid. Once the liquid fills the burette, the faucet 18 is closed, and the Central tap 15put in a position in which the burette is connected with the absorption vessel.
Lowering the levelling bottle, allow the liquid to drain out of the burette into the surge bottle. The level of alkaline solution in the absorption vessel rises, lifting the float. As soon as the float will close the exit from the absorption vessel, the Central tap 15 and the valve 18is put in the position at which the burette is connected with the absorption vessel.
Lowering the levelling bottle, allow the liquid to drain out of the burette into the surge bottle. The level of alkaline solution in the absorption vessel rises, lifting the float. As soon as the float will close the exit from the absorption vessel, the Central tap 15 and the valve 18is put in the position at which the burette is connected with the atmosphere. Raising the levelling bottle, fill the burette with the liquid to the upper limit. When the burette is filled with a liquid, the faucet 18 is closed, and the levelling bottle is lowered. If the unit is sealed, the absorption vessel is filled with alkali, and the liquid level in the measuring burette should remain unchanged. If the measuring liquid in the burette is lowered, it indicates that the device is not sealed. It should be to disassemble, clean the valves, lubricate them with vaseline and re-test the apparatus for leaks.
To control the operation of the unit before starting work and after every 2−3 hours while you work burn 2−3 titanium sample with known carbon content close to the carbon content in the test sample.
5.3 procedures for measuring
5.3.1 At the bottom of the boat is placed a sample of titanium with a mass of 1 g, cover with a layer of flux — copper oxide in a ratio of 1:4 and the boat placed in the heated portion of the porcelain tube. The tube closed with a stopper, connecting, thus, a furnace with an oxygen tank. Then miss pre-purified oxygen at a speed of 4−5 bubbles per second. A tap 15 for some time, disconnect the refrigerator and audiometr to the beginning of the burning took place under a certain pressure of oxygen. The crane 15 is put in a position in which the gas mixture enters the gas measuring burette. The surge put the bottle on the stand, in the upper part of the detector. In this position, leave the surge bottle as long as oxygen and the products of combustion will not displace liquid from the top of audiometry. After this surge, the flask is put in the down position, leave for as long as the liquid level in the measuring burette does not fall approximately to zero, and then disconnect the plug with the porcelain tube and the tube is removed from the boat. The level of liquid is installed in eudiometry at the zero scale division, and the level in the surge flask should be on the same horizontal level of liquid in the burette. Then, changing the position of the valve 15, the gas mixture (carbon dioxide+oxygen) from the gas measuring burette transferred to the sink, making sure that in the upper part of the burette is left of gas bubbles. From the filter residue was again pumped into the burette. This operation is repeated twice. Then set the crane 15 in a position of complete separation of gas-measuring burette with the absorber and measure the volume of gas in the burette. To this end, the liquid in the surge flask and the measuring burette set at the same level, allowed to stand for 1 min to drain the liquid remaining on the walls of the burette, and then to match sure the meniscus is on the scale of a measuring burette, determine the amount of the absorbed carbon dioxide is proportional to the carbon content in the analyzed material, fixing the appropriate scale division. At the same time record the temperature.
5.3.2 Control experiment is conducted through all stages of the analysis. For this purpose the boat is placed a flux — copper oxide in an amount, specified in 5.3.1, and then act in accordance with
After performing the analysis, the burette is released from the gas and prepare the apparatus for the next analysis according
5.4 the Processing of the measurement results
Mass fraction of carbon , % calculated according to the formula
where is the reading on the scale of audiometry after combustion of the sample, %;
— the scale reading of audiometry after burning in the reference experiment, %;
— correction factor for temperature and pressure;
— the weight of the portion of the sample,
5.5 Permissible error of measurement
5.5.1 the discrepancy between the measurement results and analysis results (at a confidence probability =0,95) shall not exceed the values specified
5.5.2 accuracy Control of the results of the analysis carried out according to standard sample in accordance with GOST 25086.
6 Coulometric method
6.1 measuring instruments and auxiliary devices
Analyzer type an-7560.
Furnace tubular type US-7077.
Flowmeter according to GOST 13045.
Pumps porcelain N 2 according to GOST 9147. Before using pumps and calcined in flowing oxygen at operating temperature within 1 h and stored in desiccator. Socket cover of the dryer must not be covered by lubricating substance.
The hook is made of heat-resistant low-carbon wire according to GOST 18143 diameter of 3−5 mm, length 600 mm.
Tube refractory mullite-siliceous recommended by the manufacturer of the analyzer.
Glass according to GOST 10727.
Fabric Petryanov type FRR-25−3.
Askari according to the current normative document.
The beach — the powdery copper oxide according to GOST 16539. Copper oxide pre-calcined in flowing oxygen at a temperature of 1073 K for 6 h. as the flux is allowed the use of other materials for a complete extraction of carbon from the sample analyzed. Allowed the burning of the sample without flux under the condition of complete extraction of carbon.
Oxygen gas according to GOST 5583.
Ethanol (ethyl alcohol) rectified technical GOST 18300.
Potassium chloride (potassium chloride) according to GOST 4234.
Galazoline potassium (potassium genesisintermedia) according to GOST 4207.
Sodium tetraborate (sodium tetraborate) according to GOST 4199.
Strontium chloride (strontium chloride) 6-water according to GOST 4140.
Manganese (IV) oxide according to GOST 4470.
State standard samples according to GOST 8.315.
The absorption solution: 50 g of potassium chloride and 50 g of the chloride of strontium is dissolved in 1000 cmof water and stirred.
Auxiliary solution: 50 g of potassium chloride, 50 g of zalesienia potassium and 1 g of sodium tetraborate is dissolved in 1000 cmof water and stirred.
6.2 preparation for measurement
6.2.1 Sample purified from possible contamination. For this purpose it is washed with ethanol in a volume 10 cmper 1 g of the sample, is then dried to remove the ethanol. If necessary, clean the analysed sample stored in a glass container.
6.2.2 preparing the analyzer an-7560 to the work carried out in accordance with the instructions contained in the passport.
Heat oven to 1473−1573 K.
Carry out the elements of the gas circuit and oxygen in the system. Set the oxygen flow rate of 0.6−0.7 DM/min.
Check the tightness of the connection gas path of the device by clamping a rubber tube that connects the throttle with the vessel sensor. The lowering of the float of the rotameter until it stops indicates the tightness of the system.
After checking the tightness of the system include an analyzer-7560. Within 30−40 minutes there is an automatic establishment of absorption pH of the solution to a pH value of 10.5.
For the calibration of the analyzer an-7560 using state standard samples of similar chemical composition to the sample and certified in accordance with GOST 8.315.
In the process of calibration take into account the evidence obtained as a result of the reference experiment.
6.3 procedures for measuring
6.3.1 Suspension of titanium with a mass of 0.5 g (when the mass fraction of carbon up to 0.1%) or 0.25 g (when the mass fraction of carbon in excess of 0.1%) was placed in a porcelain boat and covered with a layer of a uniform layer of copper oxide in the ratio of 1:2 by weight. Analyze the sample and the copper oxide is weighed on a laboratory balance with a weighing error of no more than 0.001 g.
A boat with hitch titanium and flux is placed in the working area of the tube, which quickly closed the metal gate, push the «reset» button and set the display indication the digital display to «zero». Burn a sample of titanium with a flux at a temperature 1473−1573 K. during combustion of the sample of titanium with a flux on the digital display by a continuous readout. Allowed analysis without the use of flux (when disagreement in assessing the quality of analysis carried out with the use of beach).
The analysis is complete, if a digital readout scoreboard does not change for 1 min or change to the idle account of the device.
6.3.2 Control experiment is conducted through all stages of the analysis. To do this, in the boat place the flux (copper oxide) in the amount stipulated in 4.3, and then act in accordance with
With an unstable value in the reference experiment, repeat it during the shift one or two times. The average value of the result of the reference experiment should not exceed the values of permissible differences for the analyzed samples are listed in table 2.
Table 2
| Mass fraction of carbon | The permissible discrepancy between the results of parallel measurements |
The permissible discrepancy between the results of the analysis | The margin of error of measurement |
| From 0,003 to 0,010 incl. | 0,002 | 0,003 |
0,002 |
| SV. 0,010 «0,030 « | 0,003 |
0,005 | 0,004 |
| «0,030» 0,080 « | 0,005 |
0,008 | 0,006 |
| «0,080» 0,200 « | 0,020 |
0,030 | 0,024 |
6.4 Processing of results of measurements
Mass fraction of carbon , % calculated according to the formula
where — the weight of the portion at which the calibrated device, g;
— reading digital display of the device, the resulting combustion of the titanium sample, %;
— the arithmetic average of the readings of the digital display device, resulting from the burning flux when conducting control experiments, %;
is the mass of the analyzed sample, samples,
When using the analyzer complete with automatic weights the formula takes the form
6.5 Permissible error of measurement
6.5.1 the discrepancy between the measurement results and analysis results (at a confidence probability =0,95) shall not exceed the values given in table 2.
6.5.2 Control the accuracy of the results of the analysis carried out according to standard sample in accordance with GOST 25086.
Allowed to monitor the accuracy of analysis results by the method of additives in accordance with GOST 25086.
7 a Method of induction heating
7.1 measuring instruments and auxiliary devices
The device analyzer is equipped with oven, induction heating oven is the catalytic afterburning of carbon monoxide to carbon dioxide and IR sensor (IR-12 «LECO») or similar.
Crucibles recommended by the manufacturer of the device, or similar crucibles made of quartz or zirconium oxide with a height of 25 mm and an outer diameter of 25 mm.
Copper metal (shavings of a thickness not exceeding 0.5 mm) according to GOST 859.
Ethanol (ethyl alcohol) rectified technical GOST 18300.
State standard samples according to GOST 8.315.
7.2 preparation for measurement
7.2.1 Analyze the sample in the form of chips or compact sample purified from possible contamination. To do this, the sample is washed with ethanol at the rate of 10 cmof ethanol per 1 g of the sample and dried at a temperature not exceeding 313 K, to the complete removal of ethanol. If necessary, purified samples stored in glass containers.
7.2.2 Copper shavings before using cleanse specified in 7.2.1 method. If necessary, copper chips stored in glass containers.
7.2.3 Crucibles before using calcined in a muffle furnace at 1273 K for 4 h. All operations with calcined crucible is carried out only with clean tweezers.
7.2.4 provisioning and enabling the analyzer is performed according to the instruction manual.
As a working gas is oxygen.
7.3 procedures for measuring
7.3.1 Installing the switch «Select Function» on the device to «Calibrate». The weight compensator is mounted on the division «1,0 Low».
Select a sample copper chip mass of 1 g, by pressing «Enter», enter the scale at the estimated device analyzer.
Put shavings on the bottom of the crucible, and the crucible inside a quartz reactor in the Central zone of the inductor. Burn a portion of copper, then the regulator «Blank Ajust» set the scoreboard zeros. For further settings of device control to repeat the experience.
7.3.2 the Calibration of an instrument performed by standard models, similar in chemical composition and carbon content for the analyzed samples and certified in accordance with GOST 8.315.
Select a portion of a standard sample weight of 1.0 g and pressing the «Enter», enter the scale at the estimated device analyzer. The sample was transferred to a crucible, cover with a uniform layer of copper shavings, taken in the ratio of 1:1 to the sample standard of the sample.
Then, the crucible covered with a lid and placed inside a quartz reactor in the Central zone of the inductor. Burn the sample and carry out the adjustment of the device until the display value corresponding certified the carbon content in the standard sample. For calibration burn a portion of the standard sample again.
7.3.3 Set the switch «Select Function» to «Operate». Taken weighed portion 1.0 g, pressing the «Enter», enter the scale at the estimated device analyzer. The sample was transferred into a ceramic crucible, cover evenly with a layer of copper shavings, taken in the ratio of 1:1 to the sample.
Cover the crucible with a lid and placed inside a quartz reactor in the Central zone of the inductor. Burn analyze a sample and record the analysis result in percentage on the scoreboard.
7.4 Processing of measurement results
Processing of measurements made by the device automatically. The result of analysis in percent is displayed on the scoreboard.
7.5 Permissible error of measurement
7.5.1 the discrepancy between the measurement results and analysis results (at a confidence probability =0,95) shall not exceed the values given in table 3.
Table 3
| Mass fraction of carbon | The permissible discrepancy between the results of the parallel measurements |
The permissible discrepancy between the results of the analysis | The margin of error of measurement |
| From to 0,0030 0,0100 incl. |
0,0010 | 0,0015 | 0,0012 |
| SV. 0,0100 «0,0300 « |
0,0020 | 0,0030 | 0,0024 |
| «0,030» 0,080 « |
0,006 | 0,009 | 0,000* |
| «0,080» 0,200 « |
0,014 | 0,020 | 0,016 |
________________
* The value corresponds to the original. — Note the manufacturer’s database.
7.5.2 Control the accuracy of the results of the analysis carried out according to standard sample in accordance with GOST 25086.
8 qualifications
To perform analysis allowed the analyst qualification not less than 4th level.
