BS EN 16091:2011 pdf download – Liquid petroleum products — Middle distillates and fatty acid methyl ester (FAME) fuels and blends — Determination of oxidation stability by rapid small scale oxidation method

BS EN 16091:2011 pdf download – Liquid petroleum products — Middle distillates and fatty acid methyl ester (FAME) fuels and blends — Determination of oxidation stability by rapid small scale oxidation method 9.1 Remove the previous test portion by means of a pipette or similar device. 9.2 Remove the used “O-ring” seal and discard. NOTE To avoid contamination of the new test, it is necessary to discard the used “O-ring” seal, because it may be soaked with oxidation products from the previous test. 9.3 Wipe the sample cup, the seal groove and the cover with lint-free cleaning tissue (5.3) soaked with cleaning solvent (5.1) until free of gum or other oxidation residues. 9.4 Allow the test sample cup and cover to dry in air and visually inspect for cleanliness . NOTE Compressed air is generally unsuitable to accelerate the evaporation of solvent because it can contain traces of oil that may influence the next test. 9.5 Insert a new “O-ring“ seal (6.3). 10 Procedure 10.1 Bring the reaction vessel and the sample to be tested to room temperature. 10.2 Using a pipette (6.2), place 5 ml ± 0,1ml of the sample into the reaction vessel sample cup. 10.3 Cover the sample-cup with the screw cap (see A.2) and close the reaction vessel. 10.4 Pre-flush the reaction vessel with oxygen. Introduce oxygen (5.2) into the vessel until a pressure of 700 kPa ± 5 kPa is attained and stabilized over 20 sec. 10.5 Start the heater with no delay between charging with oxygen and starting the test. 10.6 The test temperature of 140 ºC ± 0,5 ºC shall be reached after 270 s ± 30 s. 10.7 If, during the initial 5 min of the test, a steady drop in pressure is observed, discontinue the test and discard the test specimen. The leakage rate at 140 ºC with empty sample cup shall not exceed a value of 2 kPa/h. If the leakage rate shows an increase, check the following components: • O-ring for damage or residues of samples, • surface of sample cup for damage, and • sample cup for sample residues. Contact the manufacturer to resolve leakage problems from other parts of the instrument. 10.8 The apparatus automatically records the temperature (to the nearest 0,1 ºC) and pressure (to the nearest 1 kPa) of the oxidation vessel continuously. 10.9 The apparatus terminates the test when the pressure readings show a...