Joint Inspection Group Bulletin 110 Use of Electronic Water Sensors

Introduction

Electronic sensors qualified against EI 1598[1], monitor the amount of free water and/or particulate matter present in aviation fuel. Recent work, with technology based on scattered light detection, has resulted in the development of water sensors that may be used as an alternative to Chemical Water Detectors (CWD), as explained below.

When inserted into fuel, these water sensors are capable of measuring free water levels both above and below the 30 ppm IATA Guidance Material limit for the free water content of aviation fuel. When fitted into pipework, this technology has the advantage of continually analysing the free water content of the flowing fuel, rather than relying upon periodic representative samples, such as with the use of CWD.

Quantitative electronic water sensors shall not be confused with qualitative electronic bulk water detectors qualified against EI 1592[2], which detect “bulk water” or water slugs that have displaced fuel within a system.

Water sensors qualified for use as an alternative to CWD

Only electronic water sensors that have been qualified against EI 1598 and have been subjected to performance testing on a test rig and in-service field trials over a 12-month period, with supportive data made available, may be used as an alternative to CWD, where CWD checks are mandated in the JIG Standards.

The scope of the field trial shall include testing of reliability and ruggedness of the sensor, to demonstrate any sensitivity to sensor positioning, safe failure modes and an ability to be successfully used and survive the rigors of operational use in a wide variety of climates.

Users may rely on third party performance tests and field trials, where data is made fully available and provides sufficient detail to cover the user’s operating environment(s). However, users are encouraged to validate that the sensors operate successfully in their operating environment(s), e.g. via a small-scale trial prior to proceeding to an extended use.

In addition, the sensor system shall conform to the latest ISO 13849 or equivalent standard, as to the design and integration of safety-related parts of control systems including the design of software.

Bulk water detectors qualified against EI 1592 shall not be used as an alternative to CWD.

Installation and Operation of Water Sensors

Electronic water sensors shall be installed in accordance with the installation requirements provided by the manufacturer, and taking into account the suitability of existing equipment on the vehicles that the sensor system will be connected to (see Appendix 1 in attachment below).

Electronic water sensors may be used as an alternative to CWD testing, where required by the JIG Standards, provided that the sensor is located in the appropriate position to meet the sampling requirements outlined in the relevant section of the JIG standards, e.g. for the Visual Check made during fuelling (JIG 1 Section 5.3.1 and 5.3.2 (a)), the sensor shall be installed downstream of the filter.

When intended to be used as an alternative to CWD during aircraft fuelling, electronic water sensors shall be installed and operated in compliance with Appendix 2 of this Bulletin and in accordance with the protocol illustrated in Figure 1.

Where used as an alternative to CWD during other operations requiring a Visual Check by the JIG standards (e.g. hydrant low point flushing), local procedures and protocols of sensor use shall be developed to meet the existing requirements of the JIG standards for that operation.

It is reminded that an Appearance Check (“Clear and Bright” assessment) of a fuel sample is an integral part of the Visual Check, therefore where such sensors are used in place of a CWD, it is still required to draw a sample for an Appearance Check.

Testing of Water Sensors

The water sensor unit shall be inspected and tested annually in accordance with the manufacturer’s instructions. The associated on-vehicle systems shall be tested at least every 3 months in accordance with the manufacturer’s instructions for testing.

Qualified Water Sensors

The electronic water sensors listed in Appendix 3 have been qualified against EI 1598 and have been subjected to performance tests and in-service field trials over a 12-month period and may be used as an alternative to CWD testing, in the context of this Bulletin.

Management of Change

Operators who intend to use a qualified water sensor in place of a CWD test kit, shall develop a Management of Change (MOC) plan for the installation, operation and maintenance of the sensors, the update of local operating manuals and procedures and training of the relevant staff, in accordance with this Bulletin, prior to using the sensors in place of CWD testing.

 

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