Gas-detecting properties of surface acoustic wave ammonia sensors

✍ Scribed by Chi-Yen Shen; Chun-Pu Huang; Wang-Tsung Huang

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 136 KB
• Volume: 101
• Category: Article
• ISSN: 0925-4005
• DOI: 10.1016/j.snb.2003.07.016

✦ Synopsis

The detecting properties of l-glutamic acid hydrochloride that is deposited on 128 • YX-LiNbO 3 surface acoustic wave (SAW) delay lines are studied in this work. SAW gas sensors that were based on l-glutamic acid hydrochloride had good sensitivity, selectivity, reversibility, and repeatability to ammonia gas. A detection limit of 0.56 ppm for gaseous ammonia was observed when using l-glutamic acid hydrochloride for the sensing film at room temperature. The response degraded at a rate of -0.01 ppm per day at room temperature, and it means that the long-term stability of l-glutamic acid hydrochloride is quite enough. The cross-sensitivity from humidity interference was approximately 0.011. Therefore, the interference from water molecules is slight in room ambient air, so the effect of humidity on SAW response is negligible.