Evaluation Of A Detector For Free Water In Fuel
Report Number: AFAPL TR 66-39
Author(s): Johnston, Robert K., Monita, Charles M.
Corporate Author(s): Southwest Research Inst San Antonio TX
Laboratory: Air Force Aero Propulsion Laboratory
Date of Publication: 1966-04
Pages: 52
Contract: AF 33(615)-2327
DoD Project: 8169
DoD Task: 816901
Identifier: AD0481506
Abstract:
A test apparatus for detecting small amounts of free water in jet fuels, which was developed by a Navy group, has been subjected to various evaluations. The test method consists of passing a fuel sample through a dye-coated test pad and then comparing the fluorescence level of the pad under ultraviolet illumination with that of permanent color standards. Based on static evaluations of the apparatus using standard water-in-fuel dispersions, the accuracy and precision are well within 5 mg/liter in the range of free water contents up to 20 mg/liter. In analyzing effluent fuel from filter-separator tests by this method, it often shows traces of free water when the standard Karl Fischer analyses indicate undersaturated fuel; this apparent discrepancy is cause by nonequilibrium conditions of water distribution in the effluent fuel. Based on rather limited data, the sensitivity of the free water detector is not affected adversely by normal concentrations of anti-icing additive, corrosion inhibitor, or iron oxide contaminant in the fuels. In comparison with the Karl Fischer method, the free water detector is far simpler and faster and is believed to give more meaningful results. The detector appears to be very suitable for use in preproduction testing of filter-separators and elements. It should also be adaptable for use in base fuel quality control by relatively unskilled personnel, particularly if equipment manufacturers can develop prepackaged pad holders and comparator viewing instruments suitable for field use. Under field conditions, direct line sampling through a water detector pad will be more reliable than the use of bottled samples. It is recommended that field trials and further laboratory evaluations should be performed to establish more firmly whether the variety of fuel contaminants encountered in the field will interfere with the sensitivity of the method.
Provenance: Lockheed Martin Missiles & Fire Control
Author(s): Johnston, Robert K., Monita, Charles M.
Corporate Author(s): Southwest Research Inst San Antonio TX
Laboratory: Air Force Aero Propulsion Laboratory
Date of Publication: 1966-04
Pages: 52
Contract: AF 33(615)-2327
DoD Project: 8169
DoD Task: 816901
Identifier: AD0481506
Abstract:
A test apparatus for detecting small amounts of free water in jet fuels, which was developed by a Navy group, has been subjected to various evaluations. The test method consists of passing a fuel sample through a dye-coated test pad and then comparing the fluorescence level of the pad under ultraviolet illumination with that of permanent color standards. Based on static evaluations of the apparatus using standard water-in-fuel dispersions, the accuracy and precision are well within 5 mg/liter in the range of free water contents up to 20 mg/liter. In analyzing effluent fuel from filter-separator tests by this method, it often shows traces of free water when the standard Karl Fischer analyses indicate undersaturated fuel; this apparent discrepancy is cause by nonequilibrium conditions of water distribution in the effluent fuel. Based on rather limited data, the sensitivity of the free water detector is not affected adversely by normal concentrations of anti-icing additive, corrosion inhibitor, or iron oxide contaminant in the fuels. In comparison with the Karl Fischer method, the free water detector is far simpler and faster and is believed to give more meaningful results. The detector appears to be very suitable for use in preproduction testing of filter-separators and elements. It should also be adaptable for use in base fuel quality control by relatively unskilled personnel, particularly if equipment manufacturers can develop prepackaged pad holders and comparator viewing instruments suitable for field use. Under field conditions, direct line sampling through a water detector pad will be more reliable than the use of bottled samples. It is recommended that field trials and further laboratory evaluations should be performed to establish more firmly whether the variety of fuel contaminants encountered in the field will interfere with the sensitivity of the method.
Provenance: Lockheed Martin Missiles & Fire Control