Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This document is drafted in accordance with the rules given in GB/T 1.1-2020 Directives for Standardization — Part 1: Rules for the Structure and Drafting of Standardizing Documents.
This document is Part 63 of GB/T 223. See Annex A for the published parts of GB/T 223.
This document replaces GB/T 223.63-1988 Methods for Chemical Analysis of Iron, Steel and Alloy — The Sodium (Potassium) Periodate Photometric Method for the Determination of Manganese Content In addition to structural adjustment and editorial changes, the following technical deviations have been made with respect to GB/T 223.63-2005:
— the scope is modified (see Clause 1 hereof; Clause 1 of Edition 1988);
— the clause “Normative References” is added (see Clause 2);
— the requirements for reagent purity and water are added (see Clause 5);
— the requirements for glass instruments and spectrophotometers are added (see Clause 6);
— the test procedures for manganese content less than 0.01% and greater than 2.0% are added (see Clause 8);
— the reference solution sampling quantity is modified (see 8.2.3 hereof; 3.2.4 of Edition 1988);
— zero calibration solution is added (see 8.2.5.1 hereof; 3.1 of Edition 1988);
— the precision is redefined (see Clause 10 and Annex B hereof; Clause 5 of Edition 1988).
This document has been redrafted and modified adoption of International Standard ISO 629:1982 Steel and Cast Iron — Determination of Manganese Content — Spectrophotometric Method, but is not equivalent to ISO 4706:2008.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This document was proposed by China Iron and Steel Industry Association.
This document is under the jurisdiction of the National Technical Committee 183 on Iron and Steel of Standardization Administration of China (SAC/TC 183).
The previous editions of this document are as follows:
— The first edition was issued in 1981 as GB/T 223.4-1981, Method 3; the first edition was revised in 1988 as GB/T 223.63-1988;
— This is the second revised edition.
Introduction
Iron and steel is the mainstay of the national economy, the lifeblood of a country and the material guarantee for the survival and development of a country. In the standard system of iron and steel, the standard system for determination method of iron, steel and alloy chemical composition is a very important part, which plays an important role in ensuring the quality of iron, steel and alloy products. The series of method standards serve the production, trade and application of iron, steel and alloy, and provide technical support for the high quality development of Chinese iron and steel industry.
GB/T 223 includes a series of standards for determination of chemical composition of iron, steel and alloy, and respectively specifies the methods to determine the total content of silicon, manganese, phosphorus, sulfur, nickel, chromium, molybdenum, copper, vanadium, aluminum, titanium, cobalt, tungsten, niobium, zirconium, tantalum, calcium, magnesium, zinc, iron, arsenic, lead, tin, antimony, bismuth, cadmium, selenium, tellurium, cerium, boron, oxygen, nitrogen, hydrogen and rare earth, and the chemical composition of hydrochloric acid and other insolubles in carbon steel and alloy products.
GB/T 223 was firstly issued in 1963 as 12 national standards for determination of chemical composition of iron and steel. With the development of analytical technology in the field of iron, steel and alloy, and the actual demand of production, the current relatively perfect standard system has been formed through continuous revision over the years. The current parts of GB/T 223 are listed in Annex A.
GB/T 223.63 specifies a method for determination of manganese content in iron, steel and alloy by sodium (potassium) periodate spectrophotometric method. It is consistent with the international standard after this revision.
Iron, Steel and Alloy — Determination of Manganese Content — Sodium (Potassium) Periodate Spectrophotometric Method
WARNING — Persons using this document should be familiar with normal laboratory practice. This document does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions.
1 Scope
This document specifies a method for determination of manganese content in iron, steel and alloy by sodium (potassium) periodate spectrophotometric method.
This document is applicable to the determination of manganese content in iron, steel, superalloy and precision alloy with a measuring range of 0.001% to 4.00%.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 6379.1 Accuracy (trueness and precision) of measurement methods and results — Part 1: General principles and definitions
GB/T 6379.2 Accuracy (trueness and precision) of measurement methods and results — Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method
GB/T 7729 Chemical analysis of metallurgical products — General rule for spectrophotometric methods
GB/T 12805 Laboratory Glassware — Burettes
GB/T 12806 Laboratory Glassware — One-mark Volumetric Flask
GB/T 12808 Laboratory glassware — One-mark pipettes
GB/T 20066 Steel and iron — Sampling and preparation of samples for the determination of chemical composition
3 Terms and Definitions
No terms and definitions are listed in this document.
4 Principle
After a test portion is dissolved in acid solution, manganese is oxidized to heptavalent with sodium (potassium) iodate in sulphuric-phosphoric acid mixture, and absorbance is measured at 530nm wavelength of spectrophotometer.
5 Reagents or Materials
Unless otherwise specified, during the analysis, use only reagents of recognized analytical reagent quality and only distilled water or water of at least equivalent purity.
5.1 Hydrofluoric acid
ρ about 1.15 g/mL.
5.2 Hydrochloric acid
ρ about 1.19 g/mL.
5.3 Nitric acid
ρ about 1.42 g/mL.
5.4 Nitric acid, 1+4
Diluted with nitric acid (5.3).
5.5 Sulfuric acid, 1+1
Diluted with sulfuric acid of ρ about 1.84 g/mL.
5.6 Perchloric acid, 1+499
Diluted with perchloric acid of ρ about 1.67 g/mL.
5.7 Phospho-perchloric acid mixture
Mix three portions of phosphoric acid (ρ about 1.69 g/mL) and one portion of perchloric acid (ρ about 1.67 g/mL).
5.8 Sodium (potassium) periodate solution, 50 g/L
Weigh 5g of sodium or potassium periodate in a 250 mL beaker, add 60 mL water and 20mL nitric acid (see 5.3), dissolve in warm heat. Cool and dilute to 100 mL with water and mix.
5.9 Sodium nitrite solution, 10 g/L
Weigh 1g sodium nitrite and dissolve it in a 250 mL beaker with 60 mL water, mix.
5.10 Manganese standard solution
5.10.1 Manganese standard solution, 500 μg/mL
Weigh 1.4383 g of potassium permanganate (mass fraction not less than 99.9%), and dissolve it in a 600 mL beaker with 300mL water, add 10 mL sulfuric acid (see 5.5). Decolorize the solution with hydrogen peroxide (ρ about 1.10 g/mL) until the red color disappears, heating and boiling for 5 min to 10 min. After cooling, transfer the solution to a 1 000 mL volumetric flask, dilute to the mark with water and mix.
Alternatively, weigh 0.5000 g of electrolytic manganese (mass fraction not less than 99.9%) [electrolytic manganese shall be washed in sulfuric acid (5 + 95) in front, after the surface of the manganese oxide is cleaned, take it out and immediately wash it with distilled water repeatedly, and then wash in anhydrous ethanol 4 to 5 times, take out and put in the dryer to dry before use] and put it in a 250mL beaker, add 20mL nitric acid (1+3), heat to dissolve. Eliminate the nitrogen oxide by boiling. Remove it and cool to room temperature, transfer to a 1000 mL volumetric flask, dilute to the mark with water and mix.
1 mL of this stock solution contains 500 μg of manganese.
5.10.2 Manganese standard solution, 100 μg/mL
Transfer 20.0 mL of manganese standard stock solution (see 5.10.1) to a 100 mL volumetric flask, dilute to the mark with water and mix.
1 mL of this stock solution contains 100 μg of manganese.
5.10.3 Manganese standard solution, 20 μg/mL
Transfer 20.0 mL of manganese standard stock solution (see 5.10.2) to a 100 mL volumetric flask, dilute to the mark with water and mix.
1 mL of this stock solution contains 20 μg of manganese.
5.11 Water, free from reducing matter
Bring to the boil water acidified with 10 mL/L of sulphuric acid (1+3), add several crystals of sodium (potassium) periodate and keep boiling for 1 min to 2 min, cool before use.
6 Apparatus
All volumetric glassware shall be in accordance with GB/T 12805, GB/T 12806 and GB/T 12808, Class A.
Ordinary laboratory apparatus and spectrophotometer.
The spectrophotometer shall meet the requirements specified in GB/T 7729. It is suitable for measuring the absorbance of solution at 530nm with 1 cm, 2 cm, 3 cm and 5 cm absorption dishes.
7 Sampling
Sampling shall be carried out in accordance with GB/T 20066 or appropriate national standards.
8 Test Procedure
8.1 Test portion
Weigh, to the nearest 0.0001g, the test portion according to Table 1 base on the manganese content.
Table 1 Test sample amount
Manganese content (mass fraction)
% Test portion
G
0.001 to 0.01 2.0
>0.01 to 0.10 0.5
>0.10 to 1.00 0.2
>1.00 to 4.00 0.1
8.2 Determination
8.2.1 Preparation of test solution
Place the test portion (see 8.1) in a 150 mL conical flask.
— For the test portion with chromium content less than 5%, add 15 mL of nitric acid (see 5.4) [add 3 to 4 drops of hydrofluoric acid (see 5.1) for the test portion with high silicon content; add 15 mL of phosphoric-perchloric acid mixture (see 5.7) for the test portion with high tungsten content (more than 5%) or insoluble content], and heat at low temperature until the reaction stops. Add 1 mL to 2 mL of hydrochloric acid (see 5.2) and continue heating until completely decomposed.
— For the test portion with high Ni-Cr content, add 10 mL (3+1), (6+1) or (10+1) of hydrochloric acid (see 5.2) and nitric acid (see 5.3) mixture, and heat at low temperature to dissolve.
Note: When the test portion is 2 g, increase the amount of acid as appropriate so that the test portion is completely dissolved.
Add 10 mL of phosphoric-perchloric acid mixture (see 5.7) [when the test portion is 2.0 g, add 15 mL of phosphoric-perchloric acid mixture (see 5.7); when the test portion with high tungsten content is dissolved with 15 mL of phosphoric-perchloric acid mixture (see 5.7), no need to add any more], heat and evaporate until perchloric acid smoke 2 min to 5 min (the test portion with high chromium content needs to oxidized chromium), slightly cold, add water to dissolve salts. If necessary, filter to eliminate graphite carbon and wash with hot perchloric acid (see 5.6).
— When the manganese content is less than 2.00%, add 10 mL of sulfuric acid (see 5.5) and dilute it with water to about 40 mL.
— When the manganese content is greater than 2.00%, add 10 mL of sulfuric acid (see 5.5), dilute with water to about 40 mL, cool to room temperature. Transfer the solution to a 100 mL volumetric flask, dilute to the mark with water and mix. Transfer 50.0 mL of the solution to a 150 mL conical flask and add 5 mL of sulfuric acid (see 5.5).
8.2.2 Chromogenic solution
Add 10 mL of sodium (potassium) poliodate solution (see 5.8) to the test solution prepared in 8.2.1, heat it to the boil and maintain it for 2 min to 3 min (to prevent spillage of test solution), cool it to room temperature; transfer the solution to a 100 mL volumetric flask, dilute to the mark with water free from reducing matter (see 5.11) and mix.
8.2.3 Preparation of reference solution
Transfer about 25 mL of chromogenic solution (see 8.2.2) to a 100 mL conical flask, and add sodium nitrite solution (see 5.9) while shaking until the purplish color is just faded (see note). Use this solution as reference solution.
Note: When the test portion with cobalt is faded with sodium nitrite solution, the reddish color of cobalt will not fade, which can be treated in the following ways: keep shaking the volumetric flask and slowly add sodium nitrite solution (see 5.9); if the sample has no change in reddish color, place the solution in the absorption dish and measure its absorbance; add sodium nitrite solution to the remaining test solution (see 5.9) and measure the absorbance again until there is no change in absorbance for two times.
Foreword II
Introduction IV
1 Scope
2 Normative References
3 Terms and Definitions
4 Principle
5 Reagents or Materials
6 Apparatus
7 Sampling
8 Test Procedure
9 Test data processing
10 Precision
11 Test Report
Annex A (Informative) Published Parts of GB/T
Annex B (Informative) Related Data of Precision Test
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This document is drafted in accordance with the rules given in GB/T 1.1-2020 Directives for Standardization — Part 1: Rules for the Structure and Drafting of Standardizing Documents.
This document is Part 63 of GB/T 223. See Annex A for the published parts of GB/T 223.
This document replaces GB/T 223.63-1988 Methods for Chemical Analysis of Iron, Steel and Alloy — The Sodium (Potassium) Periodate Photometric Method for the Determination of Manganese Content In addition to structural adjustment and editorial changes, the following technical deviations have been made with respect to GB/T 223.63-2005:
— the scope is modified (see Clause 1 hereof; Clause 1 of Edition 1988);
— the clause “Normative References” is added (see Clause 2);
— the requirements for reagent purity and water are added (see Clause 5);
— the requirements for glass instruments and spectrophotometers are added (see Clause 6);
— the test procedures for manganese content less than 0.01% and greater than 2.0% are added (see Clause 8);
— the reference solution sampling quantity is modified (see 8.2.3 hereof; 3.2.4 of Edition 1988);
— zero calibration solution is added (see 8.2.5.1 hereof; 3.1 of Edition 1988);
— the precision is redefined (see Clause 10 and Annex B hereof; Clause 5 of Edition 1988).
This document has been redrafted and modified adoption of International Standard ISO 629:1982 Steel and Cast Iron — Determination of Manganese Content — Spectrophotometric Method, but is not equivalent to ISO 4706:2008.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This document was proposed by China Iron and Steel Industry Association.
This document is under the jurisdiction of the National Technical Committee 183 on Iron and Steel of Standardization Administration of China (SAC/TC 183).
The previous editions of this document are as follows:
— The first edition was issued in 1981 as GB/T 223.4-1981, Method 3; the first edition was revised in 1988 as GB/T 223.63-1988;
— This is the second revised edition.
Introduction
Iron and steel is the mainstay of the national economy, the lifeblood of a country and the material guarantee for the survival and development of a country. In the standard system of iron and steel, the standard system for determination method of iron, steel and alloy chemical composition is a very important part, which plays an important role in ensuring the quality of iron, steel and alloy products. The series of method standards serve the production, trade and application of iron, steel and alloy, and provide technical support for the high quality development of Chinese iron and steel industry.
GB/T 223 includes a series of standards for determination of chemical composition of iron, steel and alloy, and respectively specifies the methods to determine the total content of silicon, manganese, phosphorus, sulfur, nickel, chromium, molybdenum, copper, vanadium, aluminum, titanium, cobalt, tungsten, niobium, zirconium, tantalum, calcium, magnesium, zinc, iron, arsenic, lead, tin, antimony, bismuth, cadmium, selenium, tellurium, cerium, boron, oxygen, nitrogen, hydrogen and rare earth, and the chemical composition of hydrochloric acid and other insolubles in carbon steel and alloy products.
GB/T 223 was firstly issued in 1963 as 12 national standards for determination of chemical composition of iron and steel. With the development of analytical technology in the field of iron, steel and alloy, and the actual demand of production, the current relatively perfect standard system has been formed through continuous revision over the years. The current parts of GB/T 223 are listed in Annex A.
GB/T 223.63 specifies a method for determination of manganese content in iron, steel and alloy by sodium (potassium) periodate spectrophotometric method. It is consistent with the international standard after this revision.
Iron, Steel and Alloy — Determination of Manganese Content — Sodium (Potassium) Periodate Spectrophotometric Method
WARNING — Persons using this document should be familiar with normal laboratory practice. This document does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions.
1 Scope
This document specifies a method for determination of manganese content in iron, steel and alloy by sodium (potassium) periodate spectrophotometric method.
This document is applicable to the determination of manganese content in iron, steel, superalloy and precision alloy with a measuring range of 0.001% to 4.00%.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 6379.1 Accuracy (trueness and precision) of measurement methods and results — Part 1: General principles and definitions
GB/T 6379.2 Accuracy (trueness and precision) of measurement methods and results — Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method
GB/T 7729 Chemical analysis of metallurgical products — General rule for spectrophotometric methods
GB/T 12805 Laboratory Glassware — Burettes
GB/T 12806 Laboratory Glassware — One-mark Volumetric Flask
GB/T 12808 Laboratory glassware — One-mark pipettes
GB/T 20066 Steel and iron — Sampling and preparation of samples for the determination of chemical composition
3 Terms and Definitions
No terms and definitions are listed in this document.
4 Principle
After a test portion is dissolved in acid solution, manganese is oxidized to heptavalent with sodium (potassium) iodate in sulphuric-phosphoric acid mixture, and absorbance is measured at 530nm wavelength of spectrophotometer.
5 Reagents or Materials
Unless otherwise specified, during the analysis, use only reagents of recognized analytical reagent quality and only distilled water or water of at least equivalent purity.
5.1 Hydrofluoric acid
ρ about 1.15 g/mL.
5.2 Hydrochloric acid
ρ about 1.19 g/mL.
5.3 Nitric acid
ρ about 1.42 g/mL.
5.4 Nitric acid, 1+4
Diluted with nitric acid (5.3).
5.5 Sulfuric acid, 1+1
Diluted with sulfuric acid of ρ about 1.84 g/mL.
5.6 Perchloric acid, 1+499
Diluted with perchloric acid of ρ about 1.67 g/mL.
5.7 Phospho-perchloric acid mixture
Mix three portions of phosphoric acid (ρ about 1.69 g/mL) and one portion of perchloric acid (ρ about 1.67 g/mL).
5.8 Sodium (potassium) periodate solution, 50 g/L
Weigh 5g of sodium or potassium periodate in a 250 mL beaker, add 60 mL water and 20mL nitric acid (see 5.3), dissolve in warm heat. Cool and dilute to 100 mL with water and mix.
5.9 Sodium nitrite solution, 10 g/L
Weigh 1g sodium nitrite and dissolve it in a 250 mL beaker with 60 mL water, mix.
5.10 Manganese standard solution
5.10.1 Manganese standard solution, 500 μg/mL
Weigh 1.4383 g of potassium permanganate (mass fraction not less than 99.9%), and dissolve it in a 600 mL beaker with 300mL water, add 10 mL sulfuric acid (see 5.5). Decolorize the solution with hydrogen peroxide (ρ about 1.10 g/mL) until the red color disappears, heating and boiling for 5 min to 10 min. After cooling, transfer the solution to a 1 000 mL volumetric flask, dilute to the mark with water and mix.
Alternatively, weigh 0.5000 g of electrolytic manganese (mass fraction not less than 99.9%) [electrolytic manganese shall be washed in sulfuric acid (5 + 95) in front, after the surface of the manganese oxide is cleaned, take it out and immediately wash it with distilled water repeatedly, and then wash in anhydrous ethanol 4 to 5 times, take out and put in the dryer to dry before use] and put it in a 250mL beaker, add 20mL nitric acid (1+3), heat to dissolve. Eliminate the nitrogen oxide by boiling. Remove it and cool to room temperature, transfer to a 1000 mL volumetric flask, dilute to the mark with water and mix.
1 mL of this stock solution contains 500 μg of manganese.
5.10.2 Manganese standard solution, 100 μg/mL
Transfer 20.0 mL of manganese standard stock solution (see 5.10.1) to a 100 mL volumetric flask, dilute to the mark with water and mix.
1 mL of this stock solution contains 100 μg of manganese.
5.10.3 Manganese standard solution, 20 μg/mL
Transfer 20.0 mL of manganese standard stock solution (see 5.10.2) to a 100 mL volumetric flask, dilute to the mark with water and mix.
1 mL of this stock solution contains 20 μg of manganese.
5.11 Water, free from reducing matter
Bring to the boil water acidified with 10 mL/L of sulphuric acid (1+3), add several crystals of sodium (potassium) periodate and keep boiling for 1 min to 2 min, cool before use.
6 Apparatus
All volumetric glassware shall be in accordance with GB/T 12805, GB/T 12806 and GB/T 12808, Class A.
Ordinary laboratory apparatus and spectrophotometer.
The spectrophotometer shall meet the requirements specified in GB/T 7729. It is suitable for measuring the absorbance of solution at 530nm with 1 cm, 2 cm, 3 cm and 5 cm absorption dishes.
7 Sampling
Sampling shall be carried out in accordance with GB/T 20066 or appropriate national standards.
8 Test Procedure
8.1 Test portion
Weigh, to the nearest 0.0001g, the test portion according to Table 1 base on the manganese content.
Table 1 Test sample amount
Manganese content (mass fraction)
% Test portion
G
0.001 to 0.01 2.0
>0.01 to 0.10 0.5
>0.10 to 1.00 0.2
>1.00 to 4.00 0.1
8.2 Determination
8.2.1 Preparation of test solution
Place the test portion (see 8.1) in a 150 mL conical flask.
— For the test portion with chromium content less than 5%, add 15 mL of nitric acid (see 5.4) [add 3 to 4 drops of hydrofluoric acid (see 5.1) for the test portion with high silicon content; add 15 mL of phosphoric-perchloric acid mixture (see 5.7) for the test portion with high tungsten content (more than 5%) or insoluble content], and heat at low temperature until the reaction stops. Add 1 mL to 2 mL of hydrochloric acid (see 5.2) and continue heating until completely decomposed.
— For the test portion with high Ni-Cr content, add 10 mL (3+1), (6+1) or (10+1) of hydrochloric acid (see 5.2) and nitric acid (see 5.3) mixture, and heat at low temperature to dissolve.
Note: When the test portion is 2 g, increase the amount of acid as appropriate so that the test portion is completely dissolved.
Add 10 mL of phosphoric-perchloric acid mixture (see 5.7) [when the test portion is 2.0 g, add 15 mL of phosphoric-perchloric acid mixture (see 5.7); when the test portion with high tungsten content is dissolved with 15 mL of phosphoric-perchloric acid mixture (see 5.7), no need to add any more], heat and evaporate until perchloric acid smoke 2 min to 5 min (the test portion with high chromium content needs to oxidized chromium), slightly cold, add water to dissolve salts. If necessary, filter to eliminate graphite carbon and wash with hot perchloric acid (see 5.6).
— When the manganese content is less than 2.00%, add 10 mL of sulfuric acid (see 5.5) and dilute it with water to about 40 mL.
— When the manganese content is greater than 2.00%, add 10 mL of sulfuric acid (see 5.5), dilute with water to about 40 mL, cool to room temperature. Transfer the solution to a 100 mL volumetric flask, dilute to the mark with water and mix. Transfer 50.0 mL of the solution to a 150 mL conical flask and add 5 mL of sulfuric acid (see 5.5).
8.2.2 Chromogenic solution
Add 10 mL of sodium (potassium) poliodate solution (see 5.8) to the test solution prepared in 8.2.1, heat it to the boil and maintain it for 2 min to 3 min (to prevent spillage of test solution), cool it to room temperature; transfer the solution to a 100 mL volumetric flask, dilute to the mark with water free from reducing matter (see 5.11) and mix.
8.2.3 Preparation of reference solution
Transfer about 25 mL of chromogenic solution (see 8.2.2) to a 100 mL conical flask, and add sodium nitrite solution (see 5.9) while shaking until the purplish color is just faded (see note). Use this solution as reference solution.
Note: When the test portion with cobalt is faded with sodium nitrite solution, the reddish color of cobalt will not fade, which can be treated in the following ways: keep shaking the volumetric flask and slowly add sodium nitrite solution (see 5.9); if the sample has no change in reddish color, place the solution in the absorption dish and measure its absorbance; add sodium nitrite solution to the remaining test solution (see 5.9) and measure the absorbance again until there is no change in absorbance for two times.
Contents of GB/T 223.63-2022
Foreword II
Introduction IV
1 Scope
2 Normative References
3 Terms and Definitions
4 Principle
5 Reagents or Materials
6 Apparatus
7 Sampling
8 Test Procedure
9 Test data processing
10 Precision
11 Test Report
Annex A (Informative) Published Parts of GB/T
Annex B (Informative) Related Data of Precision Test
