CN103616345A - Carbon content measurement method for infrared carbon and sulfur analyzer - Google Patents

Abstract

The invention discloses a carbon content measurement method for an infrared carbon and sulfur analyzer. The method comprises the following steps: performing linear substitution on the absorbance obtained at each measurement point by using a Y=aA<2>+bA+c model, establishing an equation set through multiple standard samples with the known carbon content, performing least squares fit on the equation set to resolve a, b and c, and finally, analyzing and calculating carbon content of a sample to be measured through a, b and c. According to the method, integral computation on an absorbance curve is avoided, meanwhile, more determination data is used, and the obtained result is accurate. According to the carbon content measurement method for the infrared carbon and sulfur analyzer, only the several standard samples need to be measured according to the method in the steps 1-3 during user correction, a, b and c are resolved, and the analyzer is conveniently used by a user.

Description

The Determination of Carbon of infrared carbon sulfur analyzer

Technical field

The present invention relates to a kind of Determination of Carbon of Infrared Carbon-sulphur analytical approach, particularly a kind of infrared carbon sulfur analyzer.

Background technology

Infrared carbon sulfur analyzer is mainly used in carbon, the element sulphur content analysis in the materials such as ferrous metal in the industries such as metallurgy, machinery, commodity inspection, scientific research, chemical industry, non-ferrous metal, rare earth metal inorganics, ore, pottery.

At present, the Determination of Carbon that infrared carbon sulfur analyzer adopts is mainly, in the process of the carbon dioxide discharging in sample combustion, constantly gather the absorbance of carbon dioxide in absorption cell, these data points are formed to the absorbance curve of sample, again absorbance curvilinear integral is obtained to total absorbance, finally by lambert-Bill law of light absorption, calculate carbon content.Because the absorbance of carbon dioxide in dispose procedure is not linear, the absorbance curve that the absorbance data point of collection forms can not meet True Data very accurately, and direct integral just can cause larger error.For improving accuracy, instrument producer, on a large amount of experiment basis, is divided into 7 to 9 sections artificially by measurement range, at each section, adds different correction factors to meet measuring accuracy.But the calibration procedure of this mode is very complicated and loaded down with trivial details, and generally user can not carry out voluntarily, needs manufacturer to send special messenger to carry out to scene, to user, makes troubles.

Summary of the invention

Technical matters to be solved by this invention is, a kind of Determination of Carbon of analyzing infrared carbon sulfur analyzer easy to use is provided.

To achieve these goals, the technical solution used in the present invention is:

A Determination of Carbon for infrared carbon sulfur analyzer, step is as follows:

(1) choose the standard model that n quality is M, the carbon content of n standard model is denoted as C _n;

(2) standard model is burnt one by one, in burning, the gas of its generation is carried out to absorbance measuring with the frequency that is greater than 10 times per second, the absorbance that records m measurement point in effective Measuring Time, the absorbance of m measurement point of n standard model is denoted as A _nm;

(3) order

the A that substitution step (2) records _nm, generate n and take the system of equations that a, b, c be unknown number, n the system of equations generating carried out to the value that least square fitting solves a, b, c;

(4) getting quality is that the testing sample of M burns, in burning, the gas of its generation is carried out to absorbance measuring with the identical frequency of step (2), in effective Measuring Time, obtain the absorbance of m measurement point, a, b, c substitution that the absorbance recording and step (3) are tried to achieve

calculate the carbon content of testing sample.

The Determination of Carbon of infrared carbon sulfur analyzer of the present invention, the absorbance that each measurement point is obtained is used Y=aA ²+ bA+c model carries out linearization replacement, standard model by a plurality of known carbon contents is set up system of equations, again system of equations is carried out to least square fitting and try to achieve a, b, c, finally by a, b, c, complete the carbon content analytical calculation of testing sample, the method has been avoided the integral and calculating to absorbance curve, the specified data of simultaneously using is more, the result obtaining is also comparatively accurate, user's timing only need be measured several standard models to the method for step (3) by step (1) and try to achieve a, b, c, has facilitated the use of user to analyser.

Accompanying drawing explanation

Fig. 1 is that carbon content is the absorbance curve map of 4.01% standard model.

Fig. 2 is that carbon content is the absorbance curve map of 1.86% standard model.

Fig. 3 is that carbon content is the absorbance curve map of 1.04% standard model.

Fig. 4 is that carbon content is the absorbance curve map of 0.107% standard model.

Fig. 5 is that carbon content is the absorbance curve map of 0.54% standard model.

Embodiment

In order to make object of the present invention, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein, only in order to explain the present invention, is not intended to limit the present invention.

Step 1 is chosen each 0.3g of standard model of 4 known carbon contents, wherein

C1=4.01%,C2=1.86%,C3=1.04%,C4=0.107%。

Step 2 is burnt 4 standard models one by one, in burning, the gas of its generation is carried out to absorbance measuring with the frequency of 12 times per second, obtains following data in effective Measuring Time:

1. the absorbance data table 1 of carbon content 4.01% standard model and absorbance curve map 1;

2. the absorbance data table 2 of carbon content 1.86% standard model and absorbance curve map 2;

3. the absorbance data table 3 of carbon content 1.04% standard model and absorbance curve map 3;

4. the absorbance data table 4 of carbon content 0.107% standard model and absorbance curve map 4;

Data measured is deposited in the main control computer of infrared carbon sulfur analyzer, hereinafter table 1, table 2, table 3, table 4, the partial data of table 5 for taking passages.

The absorbance data of table 1 carbon content 4.01% standard model

A11

A12

A13

A14

A15

A16

A17

…

A1m

2.7E-04

4.4E-04

8.1E-04

1.4E-03

2.2E-03

3.3E-03

5.1E-03

…

1.2E-02

The absorbance data of table 2 carbon content 1.86% standard model

A21

A22

A23

A24

A25

A26

A27

…

A2m

1.9E-04

2.6E-04

5.7E-04

1.1E-03

1.6E-03

2.6E-03

4.1E-03

…

4.9E-03

The absorbance data of table 3 carbon content 1.04% standard model

A31

A32

A33

A34

A35

A36

A37

…

A3m

1.7E-04

3.5E-04

4.5E-04

8.6E-04

1.3E-03

1.8E-03

2.8E-03

…

2.9E-03

The absorbance data of table 4 carbon content 0.107% standard model

A41

A42

A43

A44

A45

A46

A47

…

A4m

1.2E-04

2.6E-04

3.0E-04

6.0E-04

9.1E-04

1.2E-03

1.9E-03

…

5.7E-04

Step 3 order

allow the resulting absorbance data of main control computer substitution step 2, obtain 4 and take the system of equations that a, b, c be unknown number:

$C_1=a\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\left(\frac{A_{1i}}{M}\right)}^2+b\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{A_{1i}}{M}+c=160.28a+326.13b+c=4.01\%$

$C_2=a\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\left(\frac{A_{2i}}{M}\right)}^2+b\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{A_{2i}}{M}+c=66.99a+188.55b+c=1.86\%$

$C_3=a\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\left(\frac{A_{3i}}{M}\right)}^2+b\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{A_{3i}}{M}+c=33.40a+125.95b+c=1.04\%$

$C_4=a\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\left(\frac{A_{4i}}{M}\right)}^2+b\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{A_{4i}}{M}+c=1.41a+23.62b+c=0.107\%$

Above-mentioned 4 system of equations are carried out to least square fitting, try to achieve a=0.0179, b=0.0035, c=-0.0011.

It is 0.54% standard model 0.3g that step 4 is got carbon content, and gas that its burning is produced carries out absorbance measuring with the frequency of 12 times per second, effectively in Measuring Time, is obtaining absorbance data table 5 and absorbance curve map 5.

The absorbance data of table 5 carbon content 0.54% standard model

A1

A2

A3

A4

A5

A6

A7

…

Am

1.4E-04

3.1E-04

4.5E-04

5.9E-04

1.0E-03

1.5E-03

2.2E-03

…

1.6E-03

By a=0.0179, b=0.0035, the data substitution formula of c=-0.0011 and table 5,

$C=a\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\left(\frac{A_i}{M}\right)}^2+b\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{A_i}{M}+c=14.28a+82.01b+c=0.54155\%$ Its analysis result 0.54155% and actual content 0.54% are consistent, and prove that this method is truly feasible.

The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any modifications of doing within the spirit and principles in the present invention, be equal to and replace and improvement etc., within all should being included in protection scope of the present invention.

Claims (1)

1. a Determination of Carbon for infrared carbon sulfur analyzer, step is as follows:

(1) choose the standard model that n quality is M, the carbon content of n standard model is denoted as C _n;

(2) standard model is burnt one by one, in burning, the gas of its generation is carried out to absorbance measuring with the frequency that is greater than 10 times per second, the absorbance that records m measurement point in effective Measuring Time, the absorbance of m measurement point of n standard model is denoted as A _nm;

(3) order

the A that substitution step (2) records _nm, generate n and take the system of equations that a, b, c be unknown number, n the system of equations generating carried out to the value that least square fitting solves a, b, c;

(4) getting quality is that the testing sample of M burns, in burning, the gas of its generation is carried out to absorbance measuring with the identical frequency of step (2), in effective Measuring Time, obtain the absorbance of m measurement point, a, b, c substitution that the absorbance recording and step (3) are tried to achieve

calculate the carbon content of testing sample.

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