Vol.2 No.3 2009

Research paper : A marked improvement in the reliability of the measurement of trace moisture in gases (H. Abe)−217−Synthesiology - English edition Vol.2 No.3 (2009) Horiba STEC Co., Ltd., and Fujikin Inc., who cooperated in the development and improvement of the instruments. I am also thankful to Mr. Masaaki Maruyama of the Chemicals Evaluation and Research Institute, who helped organize the calibration service system. I thank all those who exchanged opinions about the performance of the conventional trace moisture analyzers.TerminologyFrost point: The temperature at which condensation occurs when a humid gas is cooled under constant pressure is called the dew point. The dew point is lower when there is less vapor content of the gas. It is called a frost point when frosting occurs below a freezing point.Primary measurement standard: A standard that is established without relation to a measurement standard of a quantity of the same kind. It has the highest metrological quality and must be given a complete table of uncertainty according to the SI.Enhancement factor: A coefficient to compensate for the change in vapor pressure caused by the presence of dry air; in the presence of dry air, the vapor pressure obtained is different from that when there is vapor only, because of the additional pressure generated by the dry air, dissolution into water, and interaction with water molecules.Term 1. Term 2.Term 3.References[1][2][3][4][5][6][7][8]International Technology Roadmap for Semiconductors 2007, http://strj-jeita.elisasp.net/strj/ITRS07/Roadmap-2007.htmY. Kobayashi, H. Mangyo, H. Ono, T. Ikeda, K. Ikenaga, I. Matsumoto, K. Sugihara and K. Shibuya: Effects of Moisture Impurities in NH3 Gas on Nitride-Semiconductor Films Grown by Metal Organic Vapor Phase Epitaxy, Taiyo Nissan Giho (Technical Report of Taiyo Nissan), 26, 1-6 (2007) (in Japanese). http://www.tn-sanso.co.jp/jp/rd/report26.htmlH. H. Funke, B. L. Grissom, C. E. McGrew and M. W. Raynor: Techniques for the measurement of trace moisture in high-purity electronic specialty gases, Rev. Sci. Instrum., 74, 3909-3933 (2003).M. Stevens and R. Benyon: Conceptual design of a low-range humidity standard generator, Papers and Abstracts from the Third International Symposium on Humidity and Moisture, 1, 103-110 (1998).H. Abe and H. Kitano: Development of humidity standard in trace-moisture region: Characteristics of humidity generation of diffusion tube humidity generator, Sens. Actuators A, 128, 202-208 (2006).L. Greenspan: Functional equations for the enhancement factors for CO2-free moist air, J. Res. Nat. Bur. Stands., 80A (Phys. and Chem.), 41-44 (1976).Japanese Industrial Standard: JIS Z 8806, Humidity - Measurement methods, Japanese Standards Association (2001) (in Japanese).D. Sonntag: Important new values of the physical constants of 1986, vapor pressure formulations based on the ITS-[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]90, and psychrometer formulae, Z. Meteorol., 70, 340-344 (1990).S. Boyes and S. Bell: Evaluation of fundamental data used in humidity metrology, NPL Report, CMAM 42 (1999).International Technology Roadmap for Semiconductors 2000 Update, http://www.itrs.net/Links/2000UpdateFinal/2kUdFinal.htmlRubotherm, http://www.rubotherm.de/H. Abe, H. Kitano and C. Takahashi: Design of the NMIJ diffusion tube humidity generator, Papers from the 4th International Symposium on Humidity and Moisture, 33-39 (2002).H. Kitano, C. Takahashi and N. Ochi: Moisture measurement in air by vacuum ultraviolet light-excited fluorescence method, Papers and Abstracts from the Third International Symposium on Humidity and Moisture, 1, 288-293 (1998).A. O’Keefe and D. A. G. Deacon: Cavity ring-down optical spectrometer for absorption measurements using pulsed laser sources, Rev. Sci. Instrum., 59, 2544-2551 (1988).G. Berden, R. Peeters and G. Meijer: Cavity ring-down spectroscopy: Experimental schemes and applications, Int. Rev. Phys. Chem., 19, 565-607 (2000).M. Mazurenka, A. J. Orr-Ewing, R. Peverall and G. A. D. Ritchie: Cavity ring-down and cavity enhanced spectroscopy using diode lasers, Annu. Rep. Prog. Chem., Sect. C, 101, 100-142 (2005).M. Kawasaki and S. Ebata: Detection of Trace Species with Cavity Ring-Down Spectroscopy, Reza Kenkyu (The Review of Laser Engineering), 34 (4), 289-294 (2006) (in Japanese).Japan Calibration Service System, http://www.iajapan.nite.go.jp/jcss/en/index.htmlS. Nakao, Y. Yokoi and M. Takamoto: Development of a calibration facility for small mass flow rates of gas and the uncertainty of a sonic venturi transfer standard, Flow Meas. Instrum., 7, 77-83 (1996).N. Bignell: Using small sonic nozzles as secondary flow standards, Flow Meas. Instrum., 11, 329-337 (2000).M. Hayakawa, Y. Ina, Y. Yokoi, M. Takamoto and S. Nakao: Development of a transfer standard with sonic venturi nozzles for small mass flow rates of gases, Flow Meas. Instrum., 11, 279-283 (2000).H. Abe and H. Kitano: Improvement of flow and pressure controls in diffusion-tube humidity generator: Performance evaluation trace-moisture generation using cavity ring-down spectroscopy: Sens. Actuators A, 136, 723-729 (2007).H. Abe, H. Tanaka and H. Kitano: Uncertainty analysis of vaporization rate in magnetic suspension balance/ diffusion-tube humidity generator, Int. J. Thermophys., 29, 1555-1566 (2008).S. A. Bell, T. Gardiner, R. M. Gee, M. Stevens, K. Waterfield and A. Woolley: An evaluation of performance of trace moisture measurement method, Proceedings of 9th International Symposium on Temperature and Thermal Measurements in Industry and Science, 1, 663-668 (2004).


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