SH/T 0336-1994 Determination of Foreign Matter Content in Lubricating Grease (Microscopic Method)

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 title / replacement relationship

• Standard number: SH/T 0336-1994 (confirmed in 2004)
• Chinese title: Determination of Foreign Matter Content in Lubricating Grease (Microscopic Method)
• English title: not provided in the available source
• Replacement relationship: replaces SH/T 0336-92
• Approval/implementation: approved by China Petrochemical Corporation 1994-03-10, implemented on 1994-10-01
• Reference adoption: former Soviet national standard ГОСТ 9270-86 "Method for Determination of Mechanical Impurities in Lubricating Grease" (original written as "TOCT 927086", requires confirmation against the source standard (source-text extraction))

2. Scope of application and non-applicability

• Scope of application: This standard specifies the microscopic method for determining the size and number of foreign particles in lubricating grease; applicable to lubricating grease.
• Non-applicability: not provided in the available source.

3. Method principle

Apply lubricating grease onto a hemocytometer, observe under a microscope, and determine the size and number of foreign particles. (Chapter 3 Method summary)

4. Reagents and materials (purity / preparation)

• No reagent items provided in the available source.
• Materials: glass cover slip (a glass cover slip engraved with a square of side length 5mm may be used instead of the cross-movement stage, see 4.3); scraper (see 5.2, 5.3).

5. Apparatus and equipment

• 4.1 Microscope: magnification approximately 100 times, equipped with an eyepiece micrometer.
• 4.2 Hemocytometer: a thick glass slide with 4 longitudinal grooves, the spaces between the grooves forming three small planes, with the middle plane lower than the two side planes by 0.1mm. The middle plane is engraved with a grid, in which the large square has a side length of 0.2mm and the small square has a side length of 0.05mm. When lubricating grease is filled on the middle plane and a glass cover slip is pressed on, the cover slip should fit tightly against the two side planes. The grooves then serve as overflow channels for excess lubricating grease.
• 4.3 Cross-movement stage: used for counting foreign particles within a square field of view of side length 5mm, or a glass cover slip engraved with a square of side length 5mm may be used instead.

6. Recommended operating conditions

• Microscope magnification: approximately 100 times (4.1).
• Observation light source: transmitted light (6.1).
• Determination of the eyepiece micrometer division value: observe the grid on the middle plane of the hemocytometer through the microscope, and measure how many divisions of the scale correspond to each side length of the large square; for example, if each side length of the large square corresponds to 10 divisions (or each side length of the small square corresponds to 2.5 divisions), then the micrometer division value is 0.2/10 (or 0.05/2.5) = 0.02mm (5.1).
• Other operating conditions are not provided in the available source.

7. Sampling and specimen preparation

• 5.2 Before each determination, wipe clean and inspect the sample-loading surface (middle plane) of the hemocytometer, the glass cover slip, and the scraper; they should be free of impurities.
• 5.3 Specimen preparation: use a clean scraper to scrape off the surface layer of the specimen. Take a small amount of specimen and place it on the middle plane of the hemocytometer, then press tightly with a glass cover slip so that it fits tightly against the two side planes. The specimen should completely fill the gap between the glass cover slip and the plane of the hemocytometer. Excess specimen is squeezed into the grooves, but the specimen must not be squeezed onto the two side planes.

8. Analysis procedure

• 6.1 Place the hemocytometer loaded with specimen and the glass cover slip on the microscope stage, and observe the lubricating grease under transmitted light so that particles are clearly visible.
• 6.2 In a thin specimen layer with an area of 5mm×5mm, determine the maximum size of foreign particles to classify particle size; for fibrous substances, the fiber diameter should be taken. The area of 5mm×5mm can be determined by the cross-movement stage or by a square engraved on the glass cover slip.
• 6.3 Record the number of opaque foreign particles and semi-transparent fibrous foreign particles in four size classes: 10–25μm, greater than 25–75μm, greater than 75–125μm, and greater than 125μm (or according to the impurity size classes specified in the product standard). (The original text "10–25pm", "25–75uam", "75–125um", "125pm" is source-text extraction noise, requires confirmation against the source standard (source-text extraction))
• 6.4 Repeat the determination 10 times, and record the total number of particles in each size class.

9. Qualitative and quantitative determination and calculation formula

• Qualitative: foreign particles refer to opaque foreign impurities and semi-transparent fibrous foreign impurities observed under transmitted light with a microscope in lubricating grease; they do not refer to components of the lubricating grease during manufacture (Chapter 2 Definition).
• Quantitative: the number of foreign particles in each size class is expressed as the arithmetic mean of 10 determinations. The content of foreign particles in each size class per 1cm³, X (particles/cm³), is calculated according to the following formula:

X = 4 × 400 × A / 10

Where:

• A —— total number of particles from 10 determinations;
• 10 —— number of determinations;
• 400 —— coefficient for converting the volume of the tested specimen (0.0025cm³) to 1cm³.

(The original formula layout is "X= 4×400", with the denominator "10" and the symbol "A" misplaced, requires confirmation against the source standard (source-text extraction); organized as above according to context.)

10. Precision

not provided in the available source.

11. Report

not provided in the available source (only 6.3 and 6.4 specify recording the number of particles and the total number of 10 determinations).

12. Referenced documents

not provided in the available source.

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 reference Q&A