CN111879652B - Correction method of hydrogen determination instrument - Google Patents
Correction method of hydrogen determination instrument Download PDFInfo
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- CN111879652B CN111879652B CN202010608265.5A CN202010608265A CN111879652B CN 111879652 B CN111879652 B CN 111879652B CN 202010608265 A CN202010608265 A CN 202010608265A CN 111879652 B CN111879652 B CN 111879652B
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Abstract
The invention discloses a correction method of a hydrogen determination instrument, which comprises the following steps: with mass M1Dissolving the anhydrous oxalic acid in a volatile solvent to obtain an oxalic acid-containing solution; presetting the mass of a sample to be detected as M2Transferring the oxalic acid-containing solution into a sample container to be treatedCompletely volatilizing the volatile solvent in the solution, and then passing through a hydrogen determination instrument to obtain the actually measured hydrogen content of the sample to be measured; according to said M1And said M2Obtaining the theoretical hydrogen content of the sample to be detected; and correcting the deviation of the hydrogen determination instrument according to the theoretical hydrogen content and the actual hydrogen content of the sample to be measured. The invention adopts oxalic acid as a standard substance to correct the hydrogen determination instrument, the oxalic acid is slightly dissolved in a volatile solvent, the volatilization speed is high, the measurement is not interfered, and the weighing error of the balance is prevented from being overlarge when a very small amount of samples are weighed by adopting a solution mode for sample adding; the standard deviation of the measurement for the 2.0ppm content is less than 0.0993 ppm.
Description
Technical Field
The invention relates to the field of detection of hydrogen elements in steel, in particular to a correction method of a hydrogen determination instrument.
Background
Currently, the method for measuring the hydrogen content in steel and nonferrous metals (aluminum, titanium, copper and the like) uses an inert gas melting-thermal conductivity or infrared method, wherein the infrared method is used for detecting the hydrogen content in the steel, and the principle is as follows: the sample to be analyzed is put into a graphite crucible in the presence of inert gas flow for heating and fusing, and the temperature of a pulse furnace for heating the graphite crucible can reach 2500 ℃. Hydrogen in the sample to be tested is represented by H2Is released and oxidized into H by rare earth copper oxide2And after O, detecting by using an infrared detector.
Calibration of the instrument with standards is required prior to sample analysis. Because of the easy diffusion of hydrogen in steel, hydrogen standards are usually granulated to about 1 gram and plated with chromium on the surface to avoid the reduction of hydrogen content after the standard has been left for a long time. Even in this case, some hydrogen standards purchased from the market still have problems of large uncertainty, low accuracy, high price, and the like. In addition, when the analyzer is calibrated with a standard sample, the uncertainty of the standard sample can be transmitted into the detection data of the sample, which adversely affects the accuracy of the analysis result of the sample. Therefore, the problems that the uncertainty of the hydrogen standard sample purchased from the market is high, the accuracy of the standard sample fixed value is poor, the content range of the standard sample cannot meet the actual analysis requirement and the like exist.
Therefore, how to develop a calibration method for a hydrogen analyzer capable of improving the accuracy of the hydrogen measurement result is a technical problem to be solved.
Disclosure of Invention
The invention aims to provide a method for correcting a hydrogen determination instrument, which can improve the accuracy of a hydrogen measurement result by using oxalic acid as a standard substance to correct the hydrogen determination instrument.
In order to achieve the above object, the present invention provides a calibration method of a hydrogen determination apparatus, the method comprising:
with mass M1Dissolving the anhydrous oxalic acid in a volatile solvent to obtain an oxalic acid-containing solution;
presetting the mass of a sample to be detected as M2Moving the oxalic acid-containing solution into a sample container, and obtaining the actually measured hydrogen content of the sample to be measured through a hydrogen determination instrument after the volatile solvent in the oxalic acid-containing solution is completely volatilized; according to said M1And said M2Obtaining the theoretical hydrogen content of the sample to be detected;
and correcting the deviation of the hydrogen determination instrument according to the theoretical hydrogen content and the actual hydrogen content of the sample to be measured.
Further, the method comprises:
with mass M1Dissolving the anhydrous oxalic acid in a volatile solvent to obtain an oxalic acid-containing solution;
weighing mass M2Mixing the oxalic acid-containing solution with the sample to be detected, and completely volatilizing the volatile solvent to obtain a hydrogen-containing sample;
obtaining the actually measured hydrogen content of the hydrogen-containing sample through a hydrogen determination instrument; according to said M1And said M2Calculating to obtain the theoretical hydrogen content of the hydrogen-containing sample;
and correcting the deviation of the hydrogen determination instrument according to the theoretical hydrogen content and the actual hydrogen content of the sample to be measured.
Further, the theoretical hydrogen content of the sample to be detected is M1/(45×M2)×106ppm。
Further, the volatile solvent is diethyl ether.
Further, the anhydrous oxalic acid is reference oxalic acid.
Further, the sample to be detected comprises high-purity iron powder, and the mass fraction of Fe in the high-purity iron powder is greater than 99.999%.
Further, the hydrogen determination instrument is an infrared hydrogen determination instrument.
Further, the mass is M1Dissolving anhydrous oxalic acid in a volatile solvent to obtain an oxalic acid-containing solution, comprising: with mass M1The anhydrous oxalic acid is dried to remove water and then dissolved in a volatile solvent to obtain oxalic acid-containing solution.
Further, the time for the volatile solvent to completely volatilize is less than 3 min.
Further, the sample container is a graphite crucible.
One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:
the invention provides a method for correcting a hydrogen determination instrument, which has the following principle: oxalic acid isolated from air is decomposed into carbon dioxide, carbon monoxide and water when heated to 189.5 deg.C, which is known from the formula and equation of oxalic acid (H)2C2O4＝＝CO2↑+CO↑+H2O), 18g of water is produced per 90g of oxalic acid by thermal decomposition, i.e. 2g of hydrogen is released. When the hydrogen determination instrument is corrected, the mass of the added oxalic acid is accurately controlled, and the mass of hydrogen released by the decomposition of the oxalic acid can be accurately calculated; dissolving a reference reagent by using a volatile solvent, slightly dissolving oxalic acid in the volatile solvent, and enabling the volatile solvent to be high in volatilization speed and not to interfere with measurement; the detection results of hydrogen with different contents can be obtained by changing the concentration and the adding amount of the oxalic acid-containing solution in a production field, the hydrogen determination instrument can be completely corrected by replacing a hydrogen standard sample, the accuracy is high, and the standard deviation of the measurement of the 2.0ppm content is less than 0.0993 ppm.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.
Fig. 1 is a flowchart of a calibration method of a hydrogen determination instrument according to the present invention.
Detailed Description
The present invention will be described in detail below with reference to specific embodiments and examples, and the advantages and various effects of the present invention will be more clearly apparent therefrom. It will be understood by those skilled in the art that these specific embodiments and examples are for the purpose of illustrating the invention and are not to be construed as limiting the invention.
Throughout the specification, unless otherwise specifically noted, terms used herein should be understood as having meanings as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. If there is a conflict, the present specification will control.
Unless otherwise specifically indicated, various raw materials, reagents, instruments, equipment and the like used in the present invention may be commercially available or may be prepared by existing methods.
In order to solve the technical problems, the general idea of the embodiment of the application is as follows:
according to an exemplary embodiment of the present invention, there is provided a calibration method of a hydrogen determination apparatus, as shown in fig. 1, including:
s1, setting the mass as M1Dissolving the anhydrous oxalic acid in a volatile solvent to obtain an oxalic acid-containing solution;
s2, presetting the mass of the sample to be detected as M2Moving the oxalic acid-containing solution into a sample container, and obtaining the actually measured hydrogen content of the sample to be measured through a hydrogen determination instrument after the volatile solvent in the oxalic acid-containing solution is completely volatilized; according to said M1And said M2Obtaining the theoretical hydrogen content of the sample to be detected;
and S3, performing deviation correction on the hydrogen determination instrument according to the theoretical hydrogen content and the actual hydrogen content of the sample to be detected.
The embodiment of the invention provides a method for correcting a hydrogen determination instrument, which has the following principle:
oxalic acid isolated from air is decomposed into carbon dioxide, carbon monoxide and water (H) when heated to 189.5 deg.C2C2O4＝＝＝CO2↑+CO↑+H2O), according to the formula and the equation of oxalic acid, 18g of water can be generated by heating and decomposing every 90g of oxalic acid, namely 2g of hydrogen is released. When the hydrogen determination instrument is corrected, the mass of the oxalic acid added into the graphite crucible is accurately controlled, and the mass of hydrogen released by the decomposition of the oxalic acid can be accurately calculated.
The theoretical hydrogen content of the sample to be detected is M1/(45×M2)×106ppm。
The analysis equipment can receive the sample mass input by the balance, and can also directly receive the input sample mass on a corresponding picture of the analysis equipment control computer. This embodiment can directly couple M1g, inputting the hydrogen determination instrument.
When the hydrogen determination instrument is corrected, the mass of the added oxalic acid is accurately controlled, and the mass of hydrogen released by the decomposition of the oxalic acid can be accurately calculated; a volatile solvent is used for dissolving a reference reagent, oxalic acid is slightly dissolved in the volatile solvent, the volatile solvent has high volatilization speed and does not interfere with measurement, and the sample is added in a solution mode, so that the overlarge error of a balance when a very small amount of samples are weighed is avoided; the accuracy is high, and the standard deviation is less than 0.0993.
As an alternative embodiment, the volatile solvent is diethyl ether. Use ether to dissolve reference reagent, oxalic acid slightly dissolves in ether, and ether volatilization rate is fast, does not disturb the survey, adopts solution mode application of sample, and the error of balance self is too big when avoiding weighing a few samples.
As an alternative embodiment, the time for complete evaporation of the ether is less than 3 min. If 0.1ml of ether solution is used, the solution can be completely volatilized within 20s by blowing with electric wind, and can be completely volatilized within 40s by natural volatilization.
According to an exemplary embodiment of the present invention, there is provided a calibration method of a hydrogen determination apparatus, the method including:
with mass M1Dissolving the anhydrous oxalic acid in a volatile solvent to obtain an oxalic acid-containing solution;
weighing mass M2Mixing the oxalic acid-containing solution with the sample to be detected, and completely volatilizing the volatile solvent to obtain a hydrogen-containing sample;
obtaining the actually measured hydrogen content of the hydrogen-containing sample through a hydrogen determination instrument; according to said M1And said M2Calculating to obtain the theoretical hydrogen content of the hydrogen-containing sample;
and correcting the deviation of the hydrogen determination instrument according to the theoretical hydrogen content and the actual hydrogen content of the sample to be measured.
In this embodiment, the mass is M2The accuracy of the sample to be detected is further improved by adopting the sample to be detected for priming.
As an optional embodiment, the sample to be tested comprises high-purity iron powder, and the mass fraction of Fe in the high-purity iron powder is greater than 99.999%. And the high-purity iron powder is adopted for priming, so that the steel sample can be completely simulated, the influence caused by matrix mismatching is avoided, and the accuracy is further improved.
As an alternative embodiment, the oxalic acid is reference oxalic acid, so that the detection result is more accurate.
As an optional implementation manner, the mass is M1Dissolving anhydrous oxalic acid in a volatile solvent to obtain an oxalic acid-containing solution, comprising:
with mass M1The anhydrous oxalic acid is dried to remove water and then dissolved in a volatile solvent to obtain oxalic acid-containing solution.
Moisture is removed firstly, so that the interference of the moisture can be eliminated, and the detection result is more accurate.
As an optional implementation manner, the hydrogen determinator is an infrared hydrogen determinator. In the prior art, an infrared hydrogen determination instrument is generally adopted for detection, but other hydrogen determination instruments are adopted for the development of the future technology, and the correction method can also be adopted for correction.
As an alternative embodiment, the sample container is a graphite crucible. In the prior art, the infrared analyzer usually adopts a graphite crucible to contain samples for detection, but does not exclude the adoption of other hydrogen determination instruments in the future development of science and technology, namely, other sample containers, and is also within the protection scope of the invention.
As an optional implementation manner, the detection conditions of the hydrogen determination instrument are as follows: degassing power (3500W); analyzing the power (2500W); analysis time (90 seconds).
The calibration method of a hydrogen determination apparatus according to the present application will be described in detail below with reference to examples, comparative examples, and experimental data.
Example 1
1. The reference oxalic acid is heated in an oven at 105 ℃ to remove water and then placed in a dryer for standby.
2. 0.4500g of reference oxalic acid is accurately weighed, dissolved by ether (analytically pure), and then the solution is subjected to constant volume to be a 100mL volumetric flask to obtain 0.45% of oxalic acid ether solution for later use; dividing 10 mL0.45% of oxalic acid ether solution into 100mL volumetric flasks, diluting to scale, and preparing 0.045% of oxalic acid ether solution;
3. accurately weighing 0.5000g of high-purity iron powder (the Fe content is more than 99.999%) and placing the high-purity iron powder in a graphite crucible, and inputting the mass of the high-purity iron powder into an infrared hydrogen determination instrument.
4. And accurately transferring 100 mu L of the oxalic acid ether solution into a graphite crucible filled with pure iron by using a micropipette, and after the ether is completely volatilized, putting the graphite crucible into an infrared hydrogen determination instrument for detection.
TABLE 1 analysis results of hydrogen by this method
As is clear from Table 1, the theoretical content of hydrogen in the sample measured by the method of the present invention was 2.0ppm, and the measurement result was 1.99ppm with a standard deviation of 0.0993 ppm. After the infrared hydrogen determination instrument is corrected by the method, the imported hydrogen standard sample is detected, the standard value is 2.2ppm, the uncertainty of the standard sample is 0.4ppm, and the measured value is 2.31ppm, so that the daily production requirement can be completely met.
Example 2
1. The reference oxalic acid is heated in an oven at 105 ℃ to remove water and then placed in a dryer for standby.
2. 0.4500g of reference oxalic acid is accurately weighed, dissolved by ether (analytically pure), and then the solution is subjected to constant volume to be a 100mL volumetric flask to obtain 0.45% of oxalic acid ether solution for later use; respectively taking 5mL of 0.45% oxalic acid ether solution into a 100mL volumetric flask, diluting to scale, and preparing into 0.0225% oxalic acid ether solution;
3. accurately weighing 0.5000g of high-purity iron powder (the Fe content is more than 99.999%) and placing the high-purity iron powder in a graphite crucible, and inputting the mass of the high-purity iron powder into an infrared hydrogen determination instrument.
4. And (3) accurately transferring 100 mu L of the oxalic acid ether solution by using a micropipette, putting the graphite crucible containing pure iron into the graphite crucible, and after the ether is completely volatilized, putting the graphite crucible into an infrared hydrogen determination instrument for detection.
TABLE 2 analysis results of hydrogen by this method
As shown in Table 2, the theoretical content of hydrogen in the sample detected by the method of the invention is 1.0ppm, the detection result is 1.01ppm, the standard deviation is 0.0920ppm, and the daily production requirement can be completely met.
Comparative example 1
The steel standard sample with the standard value of hydrogen content purchased from the market of 2.2ppm is used for detecting the result precision, and the analysis result is as follows:
TABLE 3 analysis results using steel standards for hydrogen
As can be seen from the data in Table 3, the standard deviation of the steel standard sample with a standard hydrogen content of 2.2ppm is 0.189, which is much larger than the standard deviations of examples 1-3.
In conclusion, the invention adopts oxalic acid as a standard substance to correct the hydrogen determination instrument, and can improve the accuracy of the hydrogen measurement result.
Finally, it should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (7)
1. A method of calibrating a hydrogen analyzer, the method comprising:
with mass M1Dissolving the anhydrous oxalic acid in a volatile solvent to obtain an oxalic acid-containing solution;
weighing mass M2Mixing the oxalic acid-containing solution with the sample to be detected, and completely volatilizing the volatile solvent to obtain a hydrogen-containing sample;
obtaining the actually measured hydrogen content of the hydrogen-containing sample through an infrared hydrogen determination instrument; according to said M1And said M2Calculating to obtain the theoretical hydrogen content of the hydrogen-containing sample;
and correcting the deviation of the infrared hydrogen determination instrument according to the theoretical hydrogen content and the actual hydrogen content of the sample to be measured.
2. The method as claimed in claim 1, wherein the theoretical hydrogen content of the sample is M1/(45 XM 2). times.106ppm。
3. The calibration method for a hydrogen determination instrument according to claim 1, wherein the volatile solvent is diethyl ether.
4. The calibration method of a hydrogen analyzer according to claim 3, wherein the time for complete volatilization of diethyl ether is less than 3 min.
5. The calibration method of a hydrogen determination instrument according to claim 1, wherein the sample to be measured comprises high-purity iron powder, and the mass fraction of Fe in the high-purity iron powder is greater than 99.999%.
6. The calibration method of a hydrogen determination instrument according to claim 1, wherein the anhydrous oxalic acid is reference oxalic acid.
7. The method of claim 1, wherein the mass is M1Dissolving the anhydrous oxalic acid in a volatile solvent to obtain an oxalic acid-containing solution, comprising:
with mass M1The anhydrous oxalic acid is dried to remove water and then dissolved in a volatile solvent to obtain oxalic acid-containing solution.
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| SE337304B (en) * | 1967-06-12 | 1971-08-02 | Centro Speriment Metallurg | |
| CA1205651A (en) * | 1983-01-22 | 1986-06-10 | Takashi Ohtsubo | Sampler and an apparatus for hydrogen determination in molten metal |
| CN1024375C (en) * | 1990-08-27 | 1994-04-27 | 上海钢铁研究所 | Standard specimen of hydrogen, oxygen and nitrogen contents in steel and its prepn. |
| CN102507894B (en) * | 2011-10-17 | 2014-08-20 | 攀钢集团江油长城特殊钢有限公司 | Method for determining hydrogen content in titanium and titanium alloy |
| US8754369B2 (en) * | 2012-06-04 | 2014-06-17 | The Boeing Company | System and method for measuring hydrogen content in a sample |
| CN103713106B (en) * | 2013-12-25 | 2016-08-24 | 国核宝钛锆业股份公司 | A kind of measure the method for protium content in nuclear-grade zirconium material |
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