Work Item
ASTM WK87304
Revision of D1655-22a Standard Specification for Aviation Turbine Fuels
Rationale
An additional method of thermal stability tube rating has been approved for D3241 Standard Test Method for Thermal Oxidation Stability of Aviation Turbine Fuels as Annex A4 Rating of D3241 Heater Tubes – Multi-Wavelength Ellipsometric Method. Reference to this D3241 Annex A4 is proposed for inclusion in D1655 Table 1 Detailed Requirements of Aviation Turbine Fuels in the section on Thermal Stability. Footnote T is revised accordingly to reflect the proposed inclusion.
The Multiwavelength Ellipsometer (MWETR), cited as the apparatus in D3241 Annex A4, has completed a pilot study and a research program (available via ASTM research report D02-1782) in which the deposit depths measured have been shown to be consistent with respect to the visual tube ratings obtained on the same heater tubes; e.g. meaning that the multiwavelength ellipsometer is capable of discerning the deposit depth that indicates whether the heater tube is either a “pass” or a “fail” consistent with the pass/fail requirement of the specification. This capability is consistent with the performance of the two other D3241 metrological annexes A2 and A3.
The Multiwavelength Ellipsometer (MWETR) has recently conducted an independent comparative study with the D3241 Annex 2 Interferometer Tube Rator (ITR) and the D3241 Annex 3 Ellipsometric Tube Rator (ETR) where fuel deposit depth measurements were found to be not significantly different between all three devices. That research report (consisting of Part A and Part B) is included with this ballot.
The precision of the multiwavelength ellipsometer is stated in the research report RR:D02-1782 as follows:
Range of Results (nm) Repeatability, r Degree of Freedom (DF) Reproducibility, R Degree of Freedom (DF)
2.8 - 234 1.0627 * X0.2 264 1.5251 * X0.2 265
At 85 nm: Repeatability = 2.58 nm and Reproducibility = 3.71 nm
To the extent possible, Subcommittee J tries to keep D1655 and D7566 as consistent as possible. Therefore this item is linked with the equivalent item for D7566 within this ballot. If a negative that cannot be resolved is received on one of these items, neither item moves forward.
Work Item Status
Date Initiated: 07-28-2023
Technical Contact: George Wilson