SH/T 0763-2005 Gasoline Engine Oil Rust Prevention Evaluation Method (BRT Method)

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Card type: Test method

1. Method number / full name / English name / replacement relationship

• Standard number: SH/T 0763—2005
• Chinese name: Gasoline Engine Oil Rust Prevention Evaluation Method (BRT Method)
• English name: Standard test method for evaluation of rust preventive characteristics of automotive engine oils (Ball rust test method)
• Replacement relationship: not provided in the available source (the foreword states "this standard is first published")
• Adoption relationship: modified adoption of ASTM D6557-00 "Standard Test Method for Evaluating Rust Prevention Performance of Gasoline Engine Oils", clause comparison see Appendix E
• Publication/implementation: published on 2005-04-11, implemented on 2005-09-01
• Issuing authority: National Development and Reform Commission of the People's Republic of China

2. Scope of application and non-applicability

• 1.1 specifies the test procedure for evaluating the rust prevention performance of liquid lubricants using the ball rust test (BRT), and is especially suitable for evaluating the rust prevention performance of gasoline engine oils under low-temperature, acidic environments.
• 1.2 is applicable to evaluating the rust prevention performance of gasoline engine oils of specifications such as API SG+, API SL/ILSAC GF-3 and ILSAC GF-4 (the source text source-text extraction reads "APISG+, API SL/IISACGF-3 and ISAC GF-4", requires confirmation against the source standard (source-text extraction)).
• 1.3 values are expressed in the SI system or other unit systems; the same quantity expressed in different unit systems cannot be exactly equal, each unit system shall be used independently, and mixing is not permitted.
• 1.4 This standard does not address safety issues related to use; users may establish appropriate safety and health measures according to actual conditions; relevant contents see 7.1.1, 7.1.2, 7.1.3, 7.1.4, 7.1.5, 7.1.6, 7.1.7, 7.1.9, 7.1.10, 7.1.11 and 8.2.1.1.
• Non-applicability: not provided in the available source.

3. Method principle

• 4.1 The test consists of multiple test tubes, each test tube contains test oil and a test specimen; the test tubes are placed on a test tube rack, the whole is fixed on a mechanical shaker, and the test temperature and shaking speed are set to specified values.
• 4.2 18 h During the test period, air and acid solution are continuously supplied to each test tube to provide a corrosive environment.
• 4.3 After the test is completed, the test specimens are removed and cleaned, and the rust prevention ability of the test oil is analyzed using an optical image system.
• 5.1 This test method can be used as an alternative method to SH/T 0512; SH/T 0512 is used to determine the ability of engine oil to protect valve train components against rust or corrosion under low-temperature, short-trip conditions, and corresponds to vehicle models used in the United States before 1978.
• 5.1.1 The correlation between this method and SH/T 0512 was obtained from most, but not all, of the test oils used for evaluation.

4. Reagents and materials (purity / preparation)

4.1 Reagents

• 7.1.1 Acid solution (Note: corrosive, hazardous to health)
  • 7.1.1.1 Hydrochloric acid preparation: prepare hydrochloric acid meeting the requirements of GB 622 into 1.0 mol/L hydrochloric acid according to the method of GB 601.
  • 7.1.1.2 According to the requirements of Table 1, accurately weigh different acid solutions using a clean beaker, add to a 1000 mL volumetric flask, add distilled water or deionized water to 1000 mL, and finally pour into a 1000 mL beaker.
  • 7.1.1.3 Place the beaker on a magnetic stirrer, adjust to a suitable speed, and stir at room temperature for 30 min.
• Table 1 Preparation of acid solution (quantities accurate to within 0.2%)

  Component	Quantity
  Acetic acid	6.646 g
  Hydrobromic acid	4.892 g
  Hydrochloric acid (1.0 mol/L)	103.232 g
  Distilled water or deionized water	Add to the 1000 mL mark

  • Note to Table 1: refers to the amount of hydrobromic acid with a concentration of 48% to be added; if the concentration of hydrobromic acid does not reach 48%, it shall be converted to an amount equivalent to the pure substance contained in the 48% concentration and added.
• 7.1.2 Acetone: analytical reagent, meeting the requirements of GB 686 (Note: flammable, hazardous to health).
• 7.1.3 n-Heptane: industrial grade, purity 38%~42% (Note: flammable, hazardous to health). (Purity value requires confirmation against the source standard (source-text extraction))
• 7.1.4 Hydrochloric acid: analytical reagent, meeting the requirements of GB 622 (Note: corrosive, hazardous to health).
• 7.1.5 Hydrobromic acid: analytical reagent, meeting the requirements of GB 621 (Note: corrosive, hazardous to health). (The source text source-text extraction reads "chlorobromic acid", requires confirmation against the source standard (source-text extraction))
• 7.1.6 Acetic acid: analytical reagent, meeting the requirements of GB 676 (Note: corrosive, hazardous to health).
• 7.1.7 Ethyl acetate: analytical reagent, meeting the requirements of GB 12589 (for precautions see the special material safety data sheet).
• 7.1.8 Anhydrous ethanol: analytical reagent, meeting the requirements of GB 678.
• 7.1.9 Isopropanol: analytical reagent (Note: flammable, toxic, hazardous to health).
• 7.1.10 n-Butanol: analytical reagent, meeting the requirements of GB 12590 (Note: flammable, hazardous to health).
• 7.1.11 Tetrahydrofuran: analytical reagent (Note: flammable, hazardous to health).
• 7.1.12 Organic solvent: preparation method see Table 2.
• Table 2 Organic solvent

  Reagent	Composition/% (volume fraction)
  Ethyl acetate	37.5
  Denatured alcohol (95% anhydrous ethanol + 5% isopropanol)	27.5
  n-Butanol	5.0
  Tetrahydrofuran	30.0

4.2 Materials

• 7.2.1 Polytetrafluoroethylene tube: inner diameter 0.8 mm (1/32 in), outer diameter 1.6 mm (1/16 in), 17 roll, 304.8 m (1000 ft)/roll.
• 7.2.2 Ethylene tube: inner diameter 3.2 mm (1/8 in), outer diameter 6.4 mm (1/4 in), length 4.6 m (15 ft).
• 7.2.3 Test tubes: several disposable special plastic syringes of 20 mL, 10 mL and 5 mL and matching connectors.
• 7.2.4 Condensing flask: Erlenmeyer flask, capacity 1000 mL.

5. Instruments and equipment

• 6.1 Test specimens: use special test specimens for the ball rust test.
  • 6.1.1 Test specimen preparation apparatus: includes general laboratory apparatus and an ultrasonic cleaning bath.
• 6.2 Air supply system: requires an air compressor; includes two sets of air filters, two sets of pressure regulators, one set of gas purifier, one set of gas distributor with 25 outlets, 25 sections of polytetrafluoroethylene tube (each section length 182.9 m (600 ft)) or a porous gas flow control system with the same function and a gas mass flow meter; the air supply system is shown in Figure 1 and Figure 2, and the calibration of the gas mass flow meter is given in Appendix A.
• 6.3 Acid solution supply system: includes a pump capable of mounting multiple syringes, each pump can mount 10 syringes; pump flow rate range: minimum 0.0001 μL/h (using 0.5 μL syringe), maximum 220.82 mL/min (using 140 mL syringe), see Figure 3 and Figure 4. (The source text source-text extraction reads "0.0001pL/h" "0.5pL", requires confirmation against the source standard (source-text extraction))
• 6.4 Test tube assembly: includes 24 disposable plastic syringes and other general laboratory apparatus.
• 6.5 Temperature and shaking speed control system: mechanical shaker, capable of providing orbital shaking motion under certain speed and temperature conditions.
  • 6.5.1 Test tube rack: a specially made test tube rack, see Figure 5 and Figure 6, including 24 test tube positions, and fixed on a 457.2 mm × 457.2 mm (18 in × 18 in) shaking platform.
• 6.6 Gas distributor: meets specified requirements, 25 outlets.
• 6.7 Exhaust system: according to the requirements of the exhaust system, a general laboratory ventilation device is required, see Figure 7.
• 6.8 Image analysis system: requires a dedicated image analysis system, including the following devices:
  • 6.8.1 Optical system and lighting equipment
    • 6.8.1.1 Nikon Epiphot 200 inverted metallurgical microscope.
    • 6.8.1.2 BZ binocular lens.
    • 6.8.1.3 RV 3 disc mechanical stage.
    • 6.8.1.4 CFWN10x wide-field eyepiece, high-definition eyepiece.
    • 6.8.1.5 BD nosepiece, with 5 objective positions.
    • 6.8.1.6 Epiphot 300 EB device.
    • 6.8.1.7 DF module.
    • 6.8.1.8 CF BD adjustment 5x/0.13 achromatic objective.
    • 6.8.1.9 CF BD adjustment 10x/0.13 achromatic objective.
    • 6.8.1.10 EPI polarizer.
    • 6.8.1.11 beam splitter.
    • 6.8.1.12 lamp shade.
    • 6.8.1.13 lamp holder.
    • 6.8.1.14 12 V/100 W halogen bulb.
    • 6.8.1.15 300V/200V 100 W power supply. (requires confirmation against the source standard (source-text extraction))
    • 6.8.1.16 connecting wire.
    • 6.8.1.17 C type connector for installing the camera.
    • 6.8.1.18 NCBI type filter.
    • 6.8.1.19 power cord.
    • 6.8.1.20 centrifugal positioning frame, with a hole of diameter 5 mm drilled in the center.
  • 6.8.2 Image acquisition hardware and software
    • 6.8.2.1 Photographic system, for research use, high resolution, model NTSG/RS-170.
    • 6.8.2.2 Acquisition system, for research use, high resolution, model NISC/RS-170.
    • 6.8.2.3 Computer system, shall meet or exceed the following specifications:
      • a) Main unit: 133 MHz CPU, 16 MB memory, 540 MB hard disk drive, 1.44 MB 3.5 in disk or 1.44 MB 5.25 in disk, CD-ROM 101 or Windows95 keyboard, SVGA video capture card, with 2 MB memory (recommended 2 MB), 2 channel ports. (requires confirmation against the source standard (source-text extraction))
      • b) Software: Windows3.x/DOS6.22 or Windows95 operating system, Microsoft Excel 7.0 (recommended Microsoft Office7). (The source text source-text extraction writes "Exce/7.0" "Ofice7", requires confirmation against the source standard (source-text extraction))
      • c) Monitor: medical, high resolution 48 cm (19 in color display).
  • 6.8.3 BRT Image analysis software
    • 6.8.3.1 BRT Macro program.
    • 6.8.3.2 Oplimate image analysis software.
• 6.9 Auxiliary equipment
  • 6.9.1 Ultrasonic cleaning bath.
  • 6.9.2 Balance: sensitivity 0.0001 g, maximum capacity 200 g.
  • 6.9.3 Vacuum pump: used for cleaning capillary tubes.
  • 6.9.4 Magnetic stirrer: stirring speed adjustable.

6. Recommended operating conditions

• Test temperature: 48 ℃ ± 0.1 ℃ (9.8, as the measured actual test oil temperature; the actual test temperature setting is determined according to Appendix B)
• Oscillation speed: 300 r/min (9.9)
• Air flow rate: 40.0 mL/min ± 0.5 mL/min (9.3, 9.11; the actual flow rate setting is determined according to Appendix A)
• Acid flow rate: 0.193 mL/h ± 0.002 mL/h (9.10; the actual flow rate setting is determined according to Appendix C)
• Test period: 18 h (9.12)
• Number of test tubes: 24 (9.14 Note: use 3 pumps, 24 test tubes; one pump can hold at most 10 test tubes, and the user may select the operating procedure according to actual conditions)

7. Sampling and specimen preparation

• 8.1 Preparation of test specimens
  • 8.1.1 Take a certain number of test specimens from the vacuum-sealed bag, place them into 120 mL clean capped bottle, add sufficient n-heptane (for precautions see 7.1.3) about 60 mL to immerse the test specimens.
  • 8.1.2 Loosen the bottle cap, place into a clean ultrasonic cleaning bath and clean for 30 min, then pour off the n-heptane.
  • 8.1.3 Then clean twice more with n-heptane, followed by one cleaning with acetone (for precautions see 7.1.2) to ensure the test specimens are clean, then blow dry with nitrogen for about 3 min.
  • Note: The test specimens may be prepared one week in advance, then stored in n-heptane until used for the test.
• 8.2 Preparation of test tube assembly
  • 8.2.1 Cut 24 sections of polytetrafluoroethylene tube, each section length 24 cm (9.5 in).
    • 8.2.1.1 Use compressed air with a minimum pressure of 0.4 MPa (50 psi) to blow dry the water/oil emulsion in the line, then clean sequentially with n-heptane (for precautions see 7.1.3) and acetone (for precautions see 7.1.2), and finally blow dry with compressed air.
  • 8.2.2 Check whether the fittings matched to the polytetrafluoroethylene tube with outer diameter 1.6 mm (1/16 in) need replacement.
  • 8.2.3 Take 24 20 mL disposable plastic syringes (test tubes), pull out the plunger, and securely fix the barrel to the short capillary tube with the matching fitting.
    • 8.2.3.1 Number the test tubes from 1 to 24.
  • 8.2.4 Place a set of test tubes on the test tube rack, with the capillary end facing up and inserted into the adjacent small holes.
  • 8.2.5 Using tweezers, take one cleaned test steel ball (test specimen) in turn and place it into each test tube.
  • 8.2.6 Using 10 mL disposable plastic syringes, respectively take 10 mL test oil and add it into the corresponding test tube.
  • 8.2.7 Use 3 pressure bars and 3 nuts to securely fix the test tubes into the corresponding test tube holes.
• 8.3 Preparation of acid supply system
  • 8.3.1 Use 5 mL disposable plastic syringe to draw about 6 mL acid from the beaker.
    • 8.3.1.1 Use a special fitting to connect the syringe to one of the acid inlets of 24 three-way valves; of the other two, one is the air inlet and the other is the acid/air mixture outlet.
    • 8.3.1.2 Open the three-way valve so that two paths are open, allowing about 0.5 mL acid to flow out, ensuring there are no bubbles in the syringe.
  • 8.3.2 Place the syringe containing about 5.5 mL acid on the pump bracket.
  • 8.3.3 Repeat steps 8.3.1 to 8.3.2 for the remaining 23 acid syringes.
  • 8.3.4 There are three pumps, and each pump can hold 10 5 mL syringes.
    • 8.3.4.1 Each pump has a push frame, and each push frame can hold 10 syringes; the flow rate range is required to meet: minimum 0.0001 μL/h (using 0.5 μL syringe), maximum 220.82 mL/min (using 140 mL syringe), precision: ±1%, reproducibility: ±0.1%. (The source text source-text extraction writes "0.0001gl/h" "0.5pL", requires confirmation against the source standard (source-text extraction))
  • 8.3.5 Use 6 special C type clamps to fix the pump, ensuring that the syringe barrel flange and plunger flange are securely fixed with clamps.
    • 8.3.5.1 Adjusting the 24 syringes is the key to good repeatability; for a photograph of the acid supply system see Figure 3, and for its structure see Figure 4.
  • 8.3.6 Cut 24 sections of polytetrafluoroethylene tube with outer diameter 1.6 mm (1/16 in), each section length 129.5 cm ± 2.5 cm (51 in ± 1 in).
    • 8.3.6.1 Connect the cut capillary tubes in turn to the acid/air mixture outlet of the corresponding three-way valve.
• 8.4 Preparation of air supply system
  • 8.4.1 It is required to supply at least 0.4 MPa (50 psi) clean dry compressed air.
  • 8.4.2 Pressure regulator, single-stage regulation, material high-purity stainless steel, pressure regulation range 0 MPa to 1.1 MPa (0 psi to 150 psi).
  • 8.4.3 Two sets of air filters, required to filter out contaminant particles in the air.
    • 8.4.3.1 The first-stage filter model is A912-DX, and the second-stage filter model is A912-BX; both sets of filters have aluminum housings, 6.4 mm (1/4 in) tapered thread (F), maximum working pressure 1.1 MPa (150 psi).
    • Note: The air output by the compressor does not require additional filtration.
  • 8.4.4 One set of gas dryer, maximum working pressure 0.7 MPa (100 psi), installed after the second-stage filter.
    • 8.4.4.1 The first part of the gas dryer, about 75%, is active molecular sieve, type 4A, pore diameter 1.68 mm to 2.38 mm.
    • 8.4.4.2 The remaining part of the gas dryer, about 25%, is water absorbent, color-indicating type, pore diameter 2.38 mm.
  • 8.4.5 Pressure micro-regulator, material high-purity stainless steel, using a sensor with working pressure 0 MPa to 0.4 MPa (0 psi to 60 psi). (The source text source-text extraction writes "Opei ~ 60pesi", requires confirmation against the source standard (source-text extraction))
  • 8.4.6 Pressure reducing valve, pressure adjustment range is 0.4 MPa–1.1 MPa (50 psi–150 psi), set pressure 0.6 MPa (80 psi), an overpressure control system is required.
  • 8.4.7 Gas distributor, 25 outlets, pipe fittings of 6.4 mm (1/4 in), see Figure 5 and Figure 6.
  • 8.4.8 Cut 25 sections of polytetrafluoroethylene tubing, each section length 182.9 m (600 ft).
    • The 8.4.8.1 long polytetrafluoroethylene tubing provides the necessary back pressure for constant air flow control, ensuring accurate air flow control; the length of each capillary section can be appropriately adjusted to ensure the same flow rate under a given delivery pressure.
    • 8.4.8.2 Connect 25 capillary sections in sequence to the gas distributor.
      • a) One of the capillary sections is connected to a digital air flow meter, which requires a measurement flow rate capable of reaching 200 mL/min, with a resolution of 0.1 mL/min, see Appendix A.
      • b) The remaining 24 capillary sections are respectively connected to the air inlets of 24 three-way valves.

8. Analysis Procedure

• 9.1 Open the three-way valve to open both paths, start the acid pump, and inject 1 mL of acid liquid into the beaker at a rate of 0.1 mL/min.
  • 9.1.1 Ensure the holder properly aligns all 24 syringe plungers.
• 9.2 Adjust the acid liquid flow rate to 0.193 mL/h (test flow rate), run for 1 h, and ensure all syringe plungers are aligned with the holder of the push plate.
• 9.3 Set the actual air flow rate to reach 40.0 mL/min ± 0.5 mL/min.
  • 9.3.1 Connect the digital air flow meter to a reference air capillary; the setting of the actual air flow rate shall be determined according to the method in Appendix A.
• 9.4 Open the three-way valve to the three-way open position, and use air to blow dry the long 129.5 cm (51 in) capillary for about 30 min.
• 9.5 Measure and record the air flow rate on all lines, then cut off the main air flow valve.
• 9.6 Connect the 24 capillary lines supplying the acid liquid/air mixture in sequence to the short capillary tubes of the corresponding test tubes.
• 9.7 Connect 24 exhaust pipes in sequence to the tops of the corresponding test tubes.
  • 9.7.1 The exhaust pipes are equipped with 24 polytetrafluoroethylene heat-resistant stoppers, with a connector diameter of 21.9 mm (19/22 in).
  • 9.7.2 Connect the exhaust pipes in sequence to the corresponding T-shaped connectors.
  • 9.7.3 Using hoses with an outer diameter of 6.4 mm (1/4 in), connect the exhaust pipes in sequence to the exhaust manifold (8 inlets); the outlet of the exhaust manifold is connected to an ethylene tube with an inner diameter of 3.2 mm (1/8 in) and an outer diameter of 6.4 mm (1/4 in), see Figure 7.
  • 9.7.4 Connect the ethylene tube to a condensation flask, the condensation flask capacity is 1000 mL, used to receive condensed water discharged by gravity, ensuring that all capillaries move freely together with the oscillation platform.
• 9.8 Set the oscillator temperature to 48 ℃ ± 0.1 ℃, as the measured actual test oil temperature, and heat the entire system to the control temperature of the oil sample; the setting of the actual test temperature shall be determined according to the method in Appendix B.
• 9.9 After the temperature reaches the test temperature, set the oscillation speed to 300 r/min, start the oscillator, and ensure that each test steel ball can rotate freely against the tube wall.
• 9.10 Start the acid pump to supply acid liquid at an actual flow rate of 0.193 mL/h ± 0.002 mL/h; the setting of the actual flow rate shall be determined according to the method in Appendix C.
• 9.11 Check and adjust the air pressure to ensure that the air flow rate can be maintained at 40.0 mL/min ± 0.5 mL/min; the setting of the actual flow rate shall be determined according to the method in Appendix A.
• 9.12 Maintain the above test conditions for 18 h.
• 9.13 After the test is completed, stop the pump, close the air valve, and stop the oscillation.
• 9.14 Remove the acid liquid/air mixture delivery line of the test tube and the connectors on the test tube.
  • Note: The procedure described above uses 3 pumps and 24 test tubes; however, one pump can accommodate up to 10 test tubes, and the user may choose the operating steps according to actual conditions.
• 10 Reference oil test: This method specifies that a reference oil must be used for each test; the test oil and the reference oil shall be tested according to the same test procedure; only when the reference oil test results meet the specified requirements can the test be considered valid.
  • Note: The purpose of the reference oil test is to prevent test deviations from exceeding the specified range.

9. Qualitative and Quantitative Analysis and Calculation Formulas

• 11.1 Preparation of test specimens for analysis
  • 11.1.1 Use a pair of long tweezers to remove the specimens from the test tubes and place them respectively into corresponding 400 mL beakers; the beakers are required to be numbered according to the test tube numbers in 8.2.3.1.
  • 11.1.2 Let each specimen swirl in a beaker of 400 mL containing sufficient n-heptane (for precautions see 7.1.3) to remove the oil film adsorbed on its surface.
  • 11.1.3 Place each specimen in an individual 20 mL cleaning bottle with small holes, and place it on the bottle rack.
  • 11.1.4 Place the bottle rack in a shallow tray, pour in sufficient n-heptane to immerse the specimens and shake for 2 min, then pour off the n-heptane.
  • 11.1.5 Pour sufficient organic solvent (see 7.1.12) into the shallow tray, immerse the specimens and keep for 10 min to remove organic deposits, then pour off the organic solvent.
  • 11.1.6 Pour sufficient n-heptane into the shallow tray, immerse the specimens and shake for 2 min, then pour off the n-heptane.
  • 11.1.7 Transfer the specimens into clean, dry, covered 20 mL vials; the vials are required to be numbered according to the test tube numbers in 8.2.3.1.
  • 11.1.8 Blow dry the specimens with nitrogen and tighten the vial caps.
• 11.2 Preparation of the rating system
  • 11.2.1 Set up the microscope adjustment system as follows:
    • 11.2.1.1 Light intensity conversion button B/D——D (black area).
    • 11.2.1.2 ND16 filter — push in (push to the first position).
    • 11.2.1.3 A filter — push in (push to the second position).
    • 11.2.1.4 F (field diaphragm control level) — open.
    • 11.2.1.5 A (aperture diaphragm control level) — open.
    • 11.2.1.6 Center-mounted neutral density filter — ND16.
    • 11.2.1.7 Objective lens magnifier — 5×.
• 11.3 Camera system
  • 11.3.1 Shutter speed — 1/60 + manual.
  • 11.3.2 White light compensation — on.
• 11.4 Turn on the image analysis computer and start the Optimate software program.
• 11.5 Run BRT 51.MAC (BRT Macro Version 5.1).
• 11.6 Rust rating program
  • 11.6.1 Wipe the specimen surface with a white silk cloth to ensure the rating surface is clean.
  • 11.6.2 Place a calibration specimen (new steel ball) under the microscope, adjust the instrument so that the ball appears on the screen, see Figure 8.
    • Note: For the detailed procedure of the analysis system, refer to the software operation manual.
  • 11.6.3 Correctly answer the questions posed by the operating program, and automatically record the readings into the chart program.
  • 11.6.4 Rotate the calibration specimen and collect 20 different readings (AGV).
  • 11.6.5 Repeat steps 11.6.1~11.6.4 for each specimen; the first and last should be reference oil specimens to ensure that no data drift occurs during the analysis process.
  • 11.6.6 Correctly save to disk and print the test results.
• Expression of results: The test results are expressed as the average of the two results of parallel samples; for the report format see Appendix D (13).
• Calculation formulas:
  • Appendix A Formula (A.1): Actual air flow rate = 100/t, where the flow rate unit is mL/min, and t is the time taken for air to flow through 100 mL, unit min.
  • Appendix C Formula (C.1): v = m/(ρ·t), where v is the actual flow rate of the acid pump (mL/h), m is the mass of acid liquid obtained after the acid pump runs for a certain time (g), ρ is the acid liquid density (g/cm³), and t is the running time of the acid pump (h).
  • The average gray value (AGV) is defined in 3.7: the measurement result of the bright area on the specimen, used to indicate the degree of corrosion inhibition.

10. Precision

• 12 Precision: The following provisions are used to judge the reliability of the determination results (confidence level of 95%).
• 12.1 Repeatability: The difference between two results obtained by the same operator on the same equipment, under the same operating conditions, using the same raw materials, and using correct and standard operating methods, for the same sample shall not exceed 15.15 (AGV). (The original text source-text extraction writes “AGY”, requires confirmation against the source standard (source-text extraction))
• 12.2 Reproducibility: The difference between two results obtained by different operators in different laboratories on different equipment, using correct and standard operating methods, for the same sample shall not exceed 18.89 (AGV).

11. Report

• 13 Result report: The test results are expressed as the average of the two results of parallel samples; for the report format see Appendix D.
• Appendix D (Normative Appendix) Test Result Report Format, Table D.1 contains the following columns:
  • Reference oil name, reference oil number, test start date, test completion date, acid solution batch number, test temperature
  • Test oil name, test oil number, test start date, test completion date, acid solution batch number, test temperature
  • Test tube position, air flow rate/(mL/min), collected data points, average gray value (AGV), parallel sample deviation, new ball gray value (AGV), average value
  • Before rating, after rating
  • Rating unit, contact telephone, operator, inspector, reviewer
  • Note: This test was conducted strictly in accordance with the XXXX standard test method, and the test results are valid.

12. Normative References

• GB 601 Chemical reagents — Preparation of standard solutions for titrimetric analysis (volumetric analysis)
• GB 621 Hydrobromic acid (the source text source-text extraction writes “nitrogen bromic acid”, requires confirmation against the source standard (source-text extraction))
• GB 622 Hydrochloric acid
• GB 676 Acetic acid
• GB 678 Anhydrous ethanol
• GB 686 Acetone
• GB 12589 Ethyl acetate
• GB 12590 n-Butanol
• SH/T 0512 Low-temperature rust evaluation method for gasoline engine oils (MS Procedure ID method)
• AISI 1040 Carbon steel
• Explanation of reference relationships (Chapter 2): For dated references, all subsequent amendments (excluding corrigenda) or revisions do not apply to this standard; for undated references, the latest edition applies to this standard.

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

14. Quick Q&A Reference