Distributed diagnostics current distribution measurement

Occurence of the disease or condition geographic distribution and frequency. Current diagnostic and therapeutic measures. 

Chapters 4-6 address specific diagnostic methods in PEFCs. Martin et al. provide a detailed review of methods for distributed diagnostics of species, temperature, and current in PEFCs in Chapter 4. In Chapter 5, Hussey and Jacobson describe the operational principles of neutron radiography for in-situ visualization of liquid water distribution, and also outline issues related to temporal and spatial resolution. Tsushima and Hirai describe both magnetic resonance imaging (MRI) technique for visualization of water in PEFCs and tunable diode laser absorption spectroscopy (TDLAS) for measurement of water vapor concentration in Chapter 6. 

Additionally, we seek diagnostic tools to understand how the fuel cell performance varies with the location in an individual fuel cell and between fuel cells in a stack. Spatial and cell-to-cell variations in current, temperature, reactant concenhation, and other parameters occur, especially at moderate to high currents and during load transients, and tools are needed which can measure or directly observe these effects. In an operating stack, the number of sensors are Umited due to various cost and size constraints, but laboratory diagnostics are very sophisticated. To understand distributed effects such as flooding in PEFCs or temperature distribution in SOFCs, direct visualization tools and sensors are... 

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