【摘要】 用纳米SnO₂制作了旁热式甲醛气敏元件,测试了气敏元件对甲醛的响应,为了提高气敏元件对低浓度甲醛的响应,组装了一套富集装置。甲醛气体通过测试腔之前,先通过富集腔对其浓缩富集一段时间,然后加热活性炭使甲醛解吸出来,送入测试腔进行测试。测试了活性炭的最佳解吸温度为160℃.比较了富集前后气敏元件对甲醛的响应,富集前后气敏元件对20 ppm(1 ppm=10^-6)甲醛的响应为分别为1.2和13.6。结果表明:富集后气敏元件对甲醛的响应明显提高。更多还原

【Abstract】 An indirect-heat formaldehyde gas sensor was fabricated with SnO₂ nano powder and the response of gas sensor for formaldehyde was tested.A preconcentrator was built up to enhance the response of gas sensor for low concentration formaldehyde. The formaldehyde was concentrated before the gas passed through the test chamber,then activated carbon was heated for desorption of formaldehyde.The best desorption temperature of activated carbon is 160℃.The responses of gas sensor for formaldehyde before and after the preconcentration were 1.2 and 13.6,respectively.The response of gas sensor to formaldehyde after the preconcentration enhanced significantly.更多还原