SH/T 0028-1990 Determination of Turbidity of Lubricating Oil Detergents

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 0028-90
• Chinese title: Determination of Turbidity of Lubricating Oil Detergents
• English title: not provided in the available source
• Replacement relationship: not provided in the available source
• Approval date: approved by China Petrochemical Corporation 1991-03-27
• Implementation date: implemented on 1992-04-01

2. Scope of application and non-applicability

• This standard specifies the method for determining the turbidity of lubricating oil detergents.
• This standard applies to the determination of lubricating oil detergents such as sulfonates, alkyl salicylates, sulfurized alkylphenates, and sulfur-phosphorized polyisobutylene barium salts.
• Not applicable: not provided in the available source.

3. Method principle

Using 150SN neutral oil as dilution oil, prepare the lubricating oil detergent into a colloidal solution with a concentration of 20% (m/m), and measure its turbidity with a turbidimeter as the turbidity of the lubricating oil detergent.

4. Reagents and materials (purity / preparation)

4.1 Materials

• Lens paper
• Silk cloth
• 150SN neutral oil
• Distilled water

4.2 Reagents

• Hexamethylenetetramine: analytical reagent
• Hydrazine sulfate: analytical reagent

4.3 Solution preparation

• 6.1.1 Hydrazine sulfate solution: weigh 1.000 g of hydrazine sulfate into a 100 mL beaker, add about 30 mL of distilled water to dissolve, quantitatively transfer to a 100 mL volumetric flask, and dilute to the mark with distilled water.
• 6.1.2 Hexamethylenetetramine solution: weigh 10.00 g of hexamethylenetetramine into a 100 mL beaker, add about 30 mL of distilled water to dissolve, quantitatively transfer to a 100 mL volumetric flask, and dilute to the mark with distilled water.
• 6.1.3 Formaldehyde azine solution: use two 5 mL pipettes to measure 5 mL each of the hydrazine sulfate solution and the hexamethylenetetramine solution, add them to a 100 mL volumetric flask, and shake well. At 25±3 °C (the original text source-text extraction is "253 °C", requires confirmation against the source standard (source-text extraction)), after standing for 24 h, dilute to the mark with distilled water. The turbidity of this solution is specified as 1120 JTU.
• 6.1.4 112 JTU formaldehyde azine solution: use a pipette to measure 10 mL 1120 JTU of the formaldehyde azine solution, place it in a 100 mL volumetric flask, and dilute to the mark with distilled water. The turbidity of this solution is specified as 112 JTU.
• Note: The above solutions are valid for use for one month.

5. Instruments and equipment

• Turbidimeter: sensitivity 0.01 JACKSON turbidity units (JTU), range 0~200 JTU
• Beaker: 100 mL
• Balance: sensitivity 0.1 mg
• Platform balance: sensitivity 0.1 g
• Pipette: 5 mL, 10 mL
• Volumetric flask: 100 mL
• Thermometer: 0~200 °C, graduation value 2 °C

6. Recommended operating conditions

• After preheating the instrument for 15 min, set the range knob to 2, then adjust to zero.
• Calibration: pour the 112 JTU formaldehyde azine solution into the calibration tube, place it in the turbidimeter, and use the calibration knob to adjust the digital display to 112.
• Range selection:
  • For samples with turbidity greater than 2 JTU and less than 20 JTU, set the range knob to 20.
  • For samples with turbidity greater than 20 JTU, set the range knob to 200.
  • For samples with turbidity greater than 200 JTU, calibrate the instrument with half the value of the self-provided reference standard solution, and multiply the measured value by 2.
  • For samples with turbidity greater than 400 JTU, calibrate the instrument with one quarter of the value of the self-provided reference standard solution, and multiply the measured value by 4.
• Measurement temperature: cool the colloidal solution to 25~32 °C.
• Measurement time limit: the prepared colloidal solution should be measured within 8 h.

7. Sampling and sample preparation

• 7.1 Weigh 10.0 g of sample into a 100 mL beaker, and add 40.0 g 150SN neutral oil as dilution oil.
• 7.2 Heat the sample with dilution oil under stirring to about 100 °C, so that the sample is completely dispersed in the dilution oil.
• 6.2 Refined dilution oil: take 150SN neutral oil, determine its water content using GB 260; the water content should be lower than 0.2% (V/V), then filter with industrial filter paper. If the water content is greater than 0.2% (V/V), first dry with calcium chloride, then filter with industrial filter paper.

8. Analysis procedure

• 7.3 At room temperature, pour the dilution oil into a test tube; after no bubbles remain, wipe the test tube with lens paper, then wipe the test tube with silk cloth, and place it into the preheated and calibrated instrument for measurement. Read the displayed values of one test tube in four different directions on the instrument, and take the average of the four values as the blank value.
• 7.4 Pour the heated colloidal solution into another test tube; first wipe the test tube with lens paper, then wipe the test tube with silk cloth. When there are no bubbles in the colloidal solution in the test tube and the temperature has cooled to 25~32 °C, place it into the instrument for measurement. Read the displayed values of one test tube in four different directions on the instrument, take the average of the four values, and subtract the blank value to obtain the turbidity of the sample.
• 6.3.3 After calibration is completed, the instrument's self-provided reference standard solution may be placed in the turbidimeter, and the displayed value recorded. Thereafter, use this value to calibrate the instrument for each measurement, and it is not necessary to prepare the formaldehyde azine solution each time. However, the instrument's self-provided reference standard solution should be calibrated with the formaldehyde azine solution at least once a month.

9. Qualitative and quantitative determination and calculation formula

• Sample turbidity = average of displayed values in four directions − blank value (average of displayed values in four directions).
• When turbidity is greater than 200 JTU: measurement result = instrument displayed value × 2.
• When turbidity is greater than 400 JTU: measurement result = instrument displayed value × 4.
• Reported value: take the arithmetic mean of two results from repeated determinations as the turbidity of the sample.

10. Precision

Precision (tentative): judge the reliability of test results according to the following provisions. Repeatability: the difference between two results from repeated determinations by the same operator shall not exceed the following values.

11. Report

Take the arithmetic mean of two results from repeated determinations as the turbidity of the sample.

12. Referenced documents

• GB 260 Determination of Water in Petroleum Products

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