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

Diserahkan: 7 Disember 2009 / Diterima: 13 Julai 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

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*Pengarang untuk surat-menyurat; email: ahmad191@salam.uitm.edu.my