SH/T 0337-1992 Determination of Evaporation Loss of Lubricating Greases

AI-translated method card — human verification pending. This is not an official translation of the standard. Unclear source values remain unverified; check the original standard and product certificate before use.

Card type: Test method

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

• Standard number: SH/T 0337-92
• Chinese title: Determination of Evaporation Loss of Lubricating Greases
• English title: not provided in the available source
• Replacement relationship: replaces SY 2723—82
• Approval/implementation: approved by China Petrochemical Corporation 1992-05-20, implemented on 1992-05-20
• First issued: 1965 year

2. Scope of application and non-applicability

• Scope of application: This standard is applicable to the determination of the evaporation loss of lubricating greases.
• Non-applicability: not provided in the available source.

3. Method principle

Place an evaporation dish filled with a thick layer of 1 mm lubricating grease in a special thermostat, maintain at the specified temperature for 1 h (or the time specified in the lubricating grease product standard), and determine the mass lost.

4. Reagents and materials (purity / preparation)

• 3.1 Rubber industry solvent naphtha.
• 3.2 White porcelain plate.
• 3.3 Wood's metal (bismuth:cadmium:tin:lead = 4:1:1:2): melting point 65 °C.
• Purity and specific preparation method: not provided in the available source.

5. Apparatus and equipment

• 4.1 Thermostat (see Figure 1): composed of a movable glass side door 2, metal outer shell 1, heating table 6, and electric heater 5 (the heater can uniformly heat the steel block placed on the heating table and the evaporation dish on the steel block to 400 °C). It is also provided with a handle 8 and a push rod 7; by means of spring 9, the steel block 3 can be pressed tightly onto the heating table 6. There are round holes 4 around the lower part of the thermostat shell to ensure that air can freely enter the thermostat.
• 4.2 Steel block: diameter 100 mm, thickness 10±0.2 mm; the steel block has a recess for inserting a thermometer, the distance from the center of the steel block to the center of the recess hole is 27 mm, the diameter of the recess is 10 mm, and the depth is 6.4±0.1 mm; insert the thermometer into the recess filled with Wood's metal; the steel block should fit closely on the heating table so that it can be heated uniformly. The surface roughness of the steel block must be machined to an Rₐ value of 0.4.
• 4.3 Evaporation dish (see Figure 2): a small steel dish; the roughness of the bottom surface of the dish must be machined to an Rₐ value of 0.4; the outer surface of each evaporation dish is numbered in sequence.
• 4.4 Temperature regulator or transformer: used to regulate the temperature of the heating table.
• 4.5 Mercury thermometer: 0～360 °C.
• 4.6 Desiccator.

6. Recommended operating conditions

• Test temperature: the temperature specified in the product standard (after the steel block temperature reaches the temperature specified in the product standard, maintain for 5 min).
• Holding time: 1 h (or the time specified in the product standard).
• Heater capacity: capable of uniformly heating the steel block and evaporation dish to 400 °C.
• Weighing accuracy: accurate to 0.0002 g.

7. Sampling and specimen preparation

• 5.1 Wash the evaporation dish clean in solvent naphtha, dry it, and weigh accurately to 0.0002 g.
• 5.2 Place the specimen into the weighed evaporation dish; bubbles are not allowed; carefully level the specimen surface with a scraper, and wipe the outer surface of the evaporation dish clean. At least four evaporation dishes shall be used for testing each specimen.
• 5.3 Weigh the evaporation dish containing the specimen accurately to 0.0002 g; the difference between the mass of specimen contained in each evaporation dish and their arithmetic mean shall not exceed ±0.01 g.
• 5.4 Place the steel block on the heating table of the thermostat, press down the push rod, close the glass side door, and begin heating; after the Wood's metal in the recess of the steel block has melted, insert the thermometer into the recess.

8. Analysis procedure

• 6.1 After the steel block temperature reaches the temperature specified in the product standard, maintain for 5 min, then place the evaporation dish containing the specimen on the steel block.
• 6.2 After the evaporation dish is placed in, immediately close the side door, record the start time of the test, and maintain in the thermostat for 1 h (or the time specified in the product standard).
• 6.3 After the specified test time is reached, turn off the electric heater, and at the same time take out the evaporation dish containing the specimen, place it on the white porcelain plate in the desiccator, cool to room temperature, and then weigh accurately to 0.0002 g.

9. Qualitative and quantitative determination and calculation formula

The evaporation loss of the specimen X [% (m/m)] is calculated according to the following formula:

X = (m₁ − m₂) / (m₁ − m₃) × 100

Where:

• m₁——mass of the evaporation dish and specimen before the test, g;
• m₂——mass of the evaporation dish and specimen after the test, g;
• m₃——mass of the evaporation dish, g.

(Note: the original source-text extraction formula was typeset as "X= plus ×100 / m one ms"; the characters in the numerator and denominator are garbled, and it has been restored to the above formula according to the context and symbol definitions; requires confirmation against the source standard (source-text extraction).)

10. Precision

• 8.1 The difference between the test result of each evaporation dish and the arithmetic mean of the test results of all evaporation dishes shall not exceed 8%.
• 8.2 When the evaporation loss is less than 5% (m/m), the difference between the test results of the evaporation dishes shall not exceed 0.4% (absolute value).

11. Report

• 9.1 If the evaporation loss of the specimen is lower than 1% (m/m), it is considered to have no evaporation.
• 9.2 Take the arithmetic mean of the results obtained from no fewer than four evaporation dishes as the determination result. If one of the four evaporation dishes has a test result exceeding the allowable difference, discard this result and take the arithmetic mean of the remaining three results as the determination result.

12. Normative references

• not provided in the available source (the main text does not list a normative reference document list).

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