Why embedded corrosion sensing is important

Jeff Demo
Electrical Systems Team Lead
Intelligent Systems Group

With its extremely negative effects on critical military assets, corrosion continues to be one of the top maintenance cost drivers for the Department of Defense. Improved health management of military aircraft is needed to control the costs of corrosion, which is estimated to be above 30% of the total maintenance costs for Navy and Air Force aviation.[i]  It is estimated that 90% of the total life cycle costs occur after aircraft delivery, and the costs due to corrosion continue to escalate as aircraft age.[ii]  The effects of corrosion are a safety issue, whereby corrosion can alter residual strength estimates and the assumptions used in managing aircraft structural integrity.[iii]  To provide in situ measurements of environmental severity, we have developed the LS2A Corrosion Monitoring Sensor Suite, a wired or wireless sensor network that measures, records, and analyzes environmental and corrosivity parameters.

Figure 1 – The Luna sensor suite for aircraft (LS2A) for corrosion monitoring. Sensor node (left) installed in an Air Force HH-60 rotorcraft (right).

Come see the demonstration for yourself

To provide industry with insights into the benefits of aircraft structural health monitoring, we will be performing Technology Demonstration sessions at the 2013 Annual Conference of the Prognostics and Health Management Society in New Orleans, LA.  We’ll demonstrate daily during the conference (October 14th -17th); providing a comprehensive demonstration of the LS2A wired and wireless corrosion monitoring sensor nodes that have been successfully deployed on a number of military rotorcraft.  The system consists of a set of sensors for measurements of relative humidity, air and surface temperature, solution conductivity, and aluminum corrosion rate, all of which will be exercised to provide real-time responses from the system.  We’ll focus on the process of setting up the sensor nodes, activating measurements, and collecting and analyzing stored data all via an easy to operate graphical user interface. 

A hands-on, interactive learning experience

Attendees of the demonstration will form small groups and each will work directly with sensor nodes and data interface stations; providing insight into the ability of embedded, intelligent sensor nodes to augment aircraft maintainer knowledge of corrosion severity and usage history.  Attendees will utilize environmental simulants such as salt solutions to excite corrosion rate and conductivity sensors, illustrating how the system will respond to real-world marine environment exposure conditions, one of the leading causes of corrosion in military aircraft.  Furthermore, long-term data, consisting of cyclic salt/humidity test runs, will be stored in the units.  The stored data will be representative of a laboratory accelerated corrosion test profile.  Attendees will be instructed on the methods of downloading stored data and using the LS2A user interface to analyze environmental severity based on the sensor node measurements and the ISO 9223 and 9224 standards for atmospheric corrosivity classification.[i] [ii]  By the completion of the session, attendees will have demonstrated the capability to configure, operate, collect data, and analyze results retrieved from the LS2A Corrosion Monitoring system.

Figure 2 – Luna’s technology demonstration will teach attendees to utilize a custom graphical user interface for configuration and operation of the LS2A Corrosion Sensor system as well as analyze data collected from the system per ISO atmospheric classification standards.

Hope to see you in one of our technology demonstration sessions

Click on the following link for details about the demonstrations http://www.phmsociety.org/events/conference/phm/13/technologyshowcase.  And for general information regarding the Annual Conference of the Prognostics and Health Management Society, please visit www.phmsociety.org.

[i] ISO 9223:1992, Corrosion of metals and alloys — Corrosivity of atmospheres — Classification. (1992).

[ii] ISO 9224:1992, Corrosion of metals and alloys — Corrosivity of atmospheres — Guiding values for the corrosivity categories. (1992).

[i] Hertzberg, E. Cost of Corrosion to DoD. (2010).at <http://www.sae.org/events/dod/presentations/2010/B3EricHerzberg.pdf>.

[ii] Matzdorf, C. Highlights of NAVAIR’s Efforts in Corrosion Control and Prevention. (2003).

[iii] AC 91-56B – Continuing Structural Integrity Program for Airplanes – Document Information. at http://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/73486.

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