K Petro company
Prev Fluency comparison test
Fluency comparison test

Work for verifying the test and analysis ability is conducted by securing the preciseness of the results of test analysis through preciseness comparison test with related organizations in Korea and participating in the comparison test held by official test organization for improving reliability of test results.

Procedures and targeted type of oil
1. Establish the plans for comparison test → 2. Receipt of participation in comparison test → 3. Distribute samples and test analysis → 4. Collect results/report results, evaluation meeting →  5. Distribute secondary standard substance (RM) grade report >feedback education →  6. Feedback education → 7. Conduct secondary comparison test → 8. Confirm 0% of error
Targeted type of oil
  • Fuel/LPG field
    1. Vehicle fuel, vehicle kerosene, diesel, LPG 2
  • Lubricant oil/ Asphalt/ Grease
    1. Internal part lubricant, turbine oil, vehicle transmission oil, ball and roller bearing grease, straight asphalt
  • Bio-diesel field
    1. Bio-diesel (BD 100)

※ Aforementioned types of oil are subject to change according to circumstances.

Test items
Criteria for selecting test items in the preciseness comparison test
  • Priority on items related to environment among the quality criteria with the oil alternative fuel as a basis and also the items from the types of oil
  • Select the issues in each type of oil that is of an issue as of now
  • Test items for the comparison are subject to change depending on the quality trend of oil products and selectively participate in the test items depending on the circumstances in the lab
Test items
손가락 좌우 표시Swipe left and right
Test feild, type, item
Field Type Test Item
Fuel/LPG field Vehicle gasoline Octane value, heavy oil feature, sulfur content, steam pressure, etc.
Vehicle diesel Density, sulfur content, flexibility, coefficient of viscosity, flashing point
Kerosene 2 type Flash point, Sulfur Content, Distillation 90% etc.
LPG 2 type Analysis, steam pressure etc.
Lubricant/ grease/asphalt field Gasoline for internal combustion engine Flashing point of internal engine lubricant, pour point, coefficient of viscosity, density, etc.
Turbine oil Flashing point, pour point, coefficient of viscosity, etc.
Automatic transmission oil flashing point, pour point, foamability, etc.
Ball and roller bearing grease Mixture, appropriate point, mixture stability, etc.
Straight asphalt Penetration, flashing point, etc.
Bio-diesel field Bio-diesel (BD100) Fatty acid methyl ester content, acid stability, coefficient of viscosity, total acid value, density, filter blocking point, etc.
Statistical method and application
Statistical method
  • Robust Statistics

    Method for minimizing the influence of extreme values on the average or standard deviation estimates and also lowering the weight on extreme value in the data group
  • Grubbs statistics

    Method for comparing the value calculated by dividing the difference between each test value and average by the standard deviation and comparing it with acceptance limit value and also the abnormal values with allowed error among the labs
  • Z-Score

    Value regulating the result values in each participating lab on the groups as a criterion for indicating the performance of test values in the comparison method between labs as a numeric value
  • Robust Statistics
    1. Collect results in each lab and calculate z-score in the use of Robust statistical results on the result values in each test item to compare the deviation of test results and evaluate preciseness
    2. As a statistical method minimizing the influence of extreme values, it calculates Z-score and compares/analyzes the abnormal values and suspicious values
Z-Score = Result - Median / Normalized IQR
  • Grubbs statistics
    1. Compare the test result values in the lab by calculating the allowed error between participating labs in each test item