Sains Malaysiana 40(1)(2011): 27–33

Effect of BaAl2O4 Addition on Power Consumption and Oxygen Sensing Response of Er123 Ceramic Rods Utilizing Hot-Spot Phenomenon

(Kesan Penambahan BaAl₂O₄ pada Penggunaan Kuasa dan Respon Pengesanan Oksigen pada Rod Seramik Er123 Menggunakan Fenomena Titik Panas)

M. Hassan & A.K. Yahya*

Faculty of Applied Sciences, Universiti Teknologi MARA

Shah Alam, Selangor D.E., Malaysia

T. Okamoto

Department of Electrical Engineering

Nagaoka University of Technology, Niigata, Japan

Received: 7 December 2009 / Accepted: 13 July 2010

ABSTRACT

In this paper, we report the effect of BaAl₂O₄ addition (0-30 wt. %) on power consumption and oxygen sensing response of hot-spots developed on short Er123 ceramic rods of around 12 mm length synthesized using standard solid-state reaction. All the sensor rods showed increase in output current with increasing voltage followed by sudden reduction in output current and appearance of hot spot. After appearance of hot spot, for each rod, output current was observed to decrease gradually with increasing voltage with the slope of the I-V curve gradually approaching zero. Output current after the hot spot formation showed sensitivity to oxygen partial pressure, pO₂ between 1 to 100 kPa. Addition of 30 wt. % BaAl₂O₄ reduced the fluctuation of current and increased the sensitivity for pO₂ below 10 kPa. In addition, overshoot current was also reduced and resulted in improvement of response time from around 10 s to 5 s. Our result also showed that minimum power consumption was significantly reduced in the Er123 rods with 30 wt. % BaAl₂O₄.

Keywords: Er123; hot spot; oxygen sensor

ABSTRAK

Dalam kertas ini, kami melaporkan kesan penambahan BaAl₂O₄ (0-30 wt. %) pada penggunaan kuasa elektrik dan respon pengesanan oksigen di titik panas yang terbentuk pada rod seramik Er123 pendek sekitar 12-mm yang disintesis menggunakan tindak balas keadaan pepejal piawai. Semua rod pengesan menunjukkan pertambahan arus output dengan bertambahnya voltan diikuti pengurangan mendadak arus output dan kemunculan titik panas. Selepas kemunculan titik panas, untuk setiap rod, arus output dicerap mengurang beransur-ansur dengan bertambahnya voltan dengan kecerunan lengkung arus-voltan beransur-ansur mendekati sifar. Arus output selepas pembentukan titik panas menunjukkan kepekaan pada tekanan separa oksigen, pO₂ antara 1 hingga 100 kPa. Penambahan 30 wt. % BaAl₂O₄ mengurangkan turun naik arus dan menambahkan kepekaan pada pO₂ di bawah 10 kPa. Tambahan lagi, ayunan lampau arus dikurangkan dan menghasilkan peningkatan masa respon dari sekitar 10 s ke 5 s. Keputusan juga menunjukkan penggunaan kuasa minimum dikurangkan dengan ketara bagi rod Er123 dengan 30 wt. % BaAl₂O₄.

Kata kunci: Er123; pengesan oksigen; titik panas

REFERENCES

Buchgeister, M.,Herzog, P., Hosseini, S.M., Kopitzki, K. & Wagener, D. 1991. Oxygen evolution from ABa₂Cu₃O_7-δ high-T_c superconductors with A=Yb, Er, Y, Gd, Eu, Sm, Nd and La. Physica C 178(1-3): 105-109.

Eguchi, Tomoyasu, Soichiro Suda, Hiroko Amasaki, Jun Kuwano & Yasukazu Saito. 1999. Optimum design for the sensing electrode mixtures of PbSnF4-based oxygen sensors for fast response at ambient temperature. Solid State Ionics 121(1-4): 235-243.

Nanda, G.P. 2008. Measurement of gas concentrations: oxygen, carbon dioxide, nitrogen, nitrous oxide and volatile anaesthetic agents. Anaesthesia & Intensive Care Medicine 9(12): 559-563.

Iihama, Kazufumi, Yuichiro Kuroki, Tomoichiro Okamoto, and Masasuke Takata. 2009. Characteristics of hot spot oxygen sensor using GdBa2Cu3O7-δ-CuO composite ceramics. Current Applied Physics 9 (3, Supplement 1): S167-S169.

Jiang, Jinjun, Lei Gao, Wei Zhong, Shen Meng, Ben Yong, Yuanlin Song, Xiangdong Wang & Chunxue Bai. 2008. Development of fiber optic fluorescence oxygen sensor in both in vitro and in vivo systems. Respiratory Physiology & Neurobiology 161(2): 160-166.

Okamoto, T., Iihama, K. & Takata, M. 2006. Hot spot oxygen sensor using GdBa₂Cu₃O_7-δ-based composite ceramics. Advanced Materials Research 11-12: 137-140.

Okamoto, T. & Takata, M. 2001. Effect of Relative Density & Length of GdBa₂Cu₃O₇-δ Ceramic Rod on Hot Spot Appearance. Transactions of the materials Research Society of Japan 26 (1): 19-22.

Okamoto, T. & Takata, M. 2004a. Characteristics of oxygen sensor exploiting the hot spot in BaAl₂O₄-added GdBa2Cu3O7−δ composite ceramic rod. Journal of the Ceramic Society of Japan 112-1: S567-S571.

Okamoto, T. & Takata, M. 2004b. Development of functional devices using hot spot in GdBa₂Cu₃O_7-d based composite ceramics. Ceramics International 30(7): 1569-1574.

Plackowski, T., Sulkowski, C., Wlosewicz, D. & Wnuk, J. 1998. Effect of the RE3+ ionic size on the REBa2Cu3O7-δ ceramics oxygenated at 250 bar. Physica C 300(3-4): 184-190.

Ramamoorthy, R.,Dutta, P.K. & Akbar, S.A. 2003. Oxygen sensors: Materials, methods, designs and applications. Journal of Materials Science 38(21): 4271-4282.

Schmid, U., Seidel, H., Mueller, G. & Becker Th. 2006. Theoretical considerations on the design of a miniaturised paramagnetic oxygen sensor. Sensors and Actuators B 116(1-2): 213-220.

Takata, M., Noguchi, Y., Kurihara, Y., Okamoto, T. & Huybrechts, B. 1999. Novel oxygen sensor using hot spot on ceramic rod. Bulletin of Materials Science 22(3): 593-600.

Tsutai, Y., Okamoto, T., Kawamoto, A. & Takata, M. 2004. Hot spot in GdBa₂Cu₃O₇-BaZrO₃. J. Ceram. Soc. Japan 112-1: S599-S601.

Warburton, Richard, P., Scott Sawtelle, R., Adam Watson, & Annie Q. Wang. 2001. Failure prediction for a galvanic oxygen sensor. Sensors and Actuators B 72(3): 197-203.

*Corresponding author; email: ahmad191@salam.uitm.edu.my