13 Minimum level of detection

Following the methods described in clause 9, the minimum concentraion of the five analytes which can be determined in unused mineral oil shall be 0.05mg/kg or lower.

In considerably oxidized samples the presence of polar compounds having similar retention times to the analytes may cause uncertainties in establishing a proper baseline and then the above detection limit may not be achieved.

14 Precision

14.1 Repeatability

When the method is correctly applied there is 5% probability that the difference between two results obtained from two tests performed on the same oil under the same conditions (same operator, same apparatus, same laboratory and short interval of time) will exceed the values given in the following table:

Note In aged oils these values may not be achieved due to interferences with ageing products.

14.2 Reproducibility

When the method is correctly applied, there is 5% probability that the difference between two single and independent results obtained by different operators working in different laboratories on identical oil will exceed the values given in the following table: