US8268493-B2  Cetegen et al., In Situ Diagnostics for Measurements of Water Vapor Partial Pressure in a PEM Fuel Cell, Feb. 2006, Journal of Fuel Cell Science and Technology, vol. 3, pp. 1-7.;  B.H. Armstrong, Spectrum Line Profiles: The Voigt Function, J. Quant. Spectrosc. Radiat. Transfer, vol. 7, pp. 61-88, (1966).;  M.L. Perry, et al., Mass Transport in Gas-Diffusion Electrodes: A Diagnostic Tool for Fuel-Cell Cathodes, J. Electrochem. Soc., vol. 145, No. 1, pp. 5-15 (1998).;  J. Stumper, et al., In-situ Methods for the Determination of Current Distributions in PEM Fuel Cells, Electrochem. Acta, vol. 43, No. 24, pp. 3773-3783, (1998).;  J.T. Mueller, et al., Characterization of Direct Methanol Fuel Cells by AC Impedance, Journal of Power Sources, vol. 75, pp, 139-143 (1998).;  L.S. Rothman, et al., J. Quant. Spectrosc. Radiat. Transfer, vol. 60, No. 5, pp. 665-710 (1998).;  G. Alberti, et al., Journal of Membrane Science, vol. 185, pp. 73-81 (2001).;  A.E. Russell, et al., In situ X-ray Absorption Spectroscopy and X-Ray Diffraction of Fuel Cell Electrocatalysts, Journal of Power Sources, vol. 96, pp. 226-232 (2001).;  P. Costamagna, et al., Quantum Jumps in the PEMFC Science and Technology From the 1960's to the Year 2000, Journal of Power Sources, vol. 102, pp. 253-269 (2001).;  R. Viswanathan, et al., In Situ X-Ray Absorption Fuel Cell, Review of Scientific Instruments, vol. 73, pp. 2124-2127 (2002).;  M.M. Mench, et al., In Situ Current Distributioin Measurements in Polymer Electrolyte Fuel Cells, Journal of the Electrochemical Society, vol. 150, No. 8, pp. A1052-A1059 (2003).;  M.M. Mench, et al., In Situ Water Distribution Measurements in a Polmer Electrolyte Fuel Cell, Journal of Power Sources, vol. 124, pp. 90-98 (2003).;  R. Satija, et al., In Situ Neutron Imaging Technique for Evaluation of Water Management Systems in Operating PEM Fuel Cells, Journal of Power Sources, vol. 129, pp. 238-245 (2004).;  I. Tkach, et al., In Situ Study of Methanol Oxidation on Pt and Pt/Ru-Mixed with Nafion Anodes in a Direct Methanol Fuel Cell by Means of FTIR Spectroscopy, Phys. Chem. Chem. Phys., vol. 6, pp. 5419-5426 (2004).;  V.R. Albertini, et al., In Situ XRD Studies of the Hydration Degree of the Polymeric Membrance in a Fuel Cell, Electrochemical and Solid-State Letters, vol. 7, No. 12, pp. A519-A521 (2005).;  F. Barbir, et al., Relationship Between Pressure Drop and Cell Resistance as a Diagnostic Tool for PEM Fuel Cells, Journal of Power Sources, vol. 141, pp. 96-101 (2005) ; and W.S. He, G.Y. Lin, T. Van Nguyen, AIChE J., 49 (2003) 3221-3228.;  D. Kramer, et al., In Situ Diagnostic of Two-Phase Flow Phenomena in Polymer Electrolyte Fuel Cells by Neutron Imaging: Part A. Experimental, Data Treatment and Quantification, Electrochemica Acta, vol. 50, pp. 2603-2614 (2005).;  Y.P. Patil, et al., In-Situ pH Measurement in a Nafion Based Polymer Electrolyte Fuel Cell by Fluorescence Spectroscopy, Prepr. Pap.-Am. Chem. Soc., Div. Fuel Chem., vol. 49, pp. 683-684 (2004).;  H. Yang, et al., In Situ Visualization Study of CO2 Gas Bubble Behavior in DMFC Anode Flow Fields, Journal of Power Sources, vol. 139, pp. 79-90 (2005).;  Y.P. Patil, et al., In Situ Water Sensing in a Nafion Membrane by Fluorescence Spectroscopy, Ind. Eng. Chem. Res., vol. 44, pp. 6141-6147 (2005).;  Q. Dong, et al., Real-Time Water Distribution in a Polymer Electrolyte Fuel Cell, Journal of Power Sources, vol. 139, pp. 106-114 (2005).;  J. Stumper, et al., In Situ Determination of MEA Resistance and Electrode Diffusivity of a Fuel Cell, Journal of the Electrochemical Society, vol. 152, pp. A837-A844 (2005).;  US Fuel Cell Council, Protocol on Fuel Cell Component Testing, Document No. USFCC 04-003, pp. cover and 1-21, www.usfcc.com.;  S.S. Penner, Quantitative Molecular Spectroscopy and Gas Emissivities, Chapter 1: Thermal Radiation, pp. 1-15, Addison-Wesley,1959.;  J. Larminie, et al., Fuel Cell Systems Explained, Chapter 1: Introduction: Hydrogen Fuel Cells_Basic Principles, Wiley, New York, 2000, pp. 1-6 and pp. 69-77.