ASTM D5006 Test Method for Measurement of Fuel System Icing Inhibitors (Ether Type) in Aviation Fuels
13. Report
13.1 Report the following information:
13.1.1 The type of fuel analyzed,
13.1.2 The volume percent DiEGME found, and
13.1.3 The temperature (°C) of the analysis.
14. Precision and Bias
14.1 The precision of this test method as determined by statistical examination of interlaboratory results according to RR:D02-1007 is as follows:
14.1.1 Repeatability - The difference between two test results obtained by the same operator with the same apparatus under constant operating conditions on identical test material would in the long run, in the normal and correct operation of the test method, exceed the following values in only one case in twenty:
HB temperature compensated refractometer:
repeatability = 0.009 volume %
Brix scale refractometer: repeatability = 0.005 volume %
14.1.2 Reproducibility - The difference between two single and independent results obtained by different operators working in different laboratories on identical test material would, in the long run, in normal and correct operation of the test method, exceed the following values only in one case in twenty:
HB temperature compensated refractometer:
reproducibility = 0.018 volume %
Brix scale refractometer: reproducibility = 0.021 volume %
NOTE 3 - Accuracy and precision in the field can be lower than a similar test done under controlled laboratory conditions using a temperature controlled precision refractometer. The MISCO Jet Fuel Refractometer (p/n JPX-DIEGME) (6.1.3) and the Gammon HB2D Refractometer (6.1.4) digital instruments have been found to provide accuracy and precision equal to the original analog instrument.
14.2 Bias - The HB temperature compensated refractometer gave results, on average, greater than the true value by 0.0018 volume %. The Brix scale refractometer gave results, on average, less than the true value by 0.0051 volume %.
15. Keywords
15.1 aviation fuel; diethylene glycol monomethyl ether; fuel system icing inhibitor; refractometry
