ASTM D3241 Method for Thermal Oxidation Stability of Aviation Turbine Fuels
ASTM D3241 Standard Test Method for Thermal Oxidation Stability of Aviation Turbine Fuels (JFTOT Procedure)
13. Report
13.1 Report the following information:
13.1.1 The heater tube control temperature. This is the test temperature of the fuel.
13.1.2 Heater tube deposit rating(s).
13.1.3 Maximum pressure drop across the filter during the test or the time required to reach a pressure differential of 25 mm Hg. For the Model 202, 203 JFTOT, report the maximum recorded ΔP found during the test.
13.1.4 If the normal 150-min test time was not completed, for example, if the test is terminated because of pressure drop failure, also report the test time that corresponds to this heater tube deposit rating.
NOTE 7 - Either the tube rating or the ΔP criteria, or both, are used to determine whether a fuel sample passes or fails the test at a specified test temperature.
13.1.5 Spent fuel at the end of a normal test. This will be the amount on top of floating piston or total fluid in displaced water beaker, depending on model of JFTOT used.
13.1.6 Heater tube serial number may be reported.
14. Precision and Bias
14.1 An interlaboratory study of JFTOT testing was conducted in accordance with Practice E 691 by eleven laboratories, using thirteen instruments including two JFTOT models with five fuels at two temperatures for a total of ten materials. Each laboratory obtained two results from each material.
14.1.1 The terms repeatability and reproducibility in this section are used as specified in Practice E 177.
14.2 Precision - It is not possible to specify the precision of this test method because it has been determined that test method results cannot be analyzed by standard statistical methodology.
14.3 Bias - This test method has no bias because jet fuel thermal oxidative stability is defined only in terms of this test method.
15. Keywords
15.1 differential pressure; fuel decomposition; oxidative deposits; test filter deposits; thermal stability; turbine fuel
