发明名称 |
Gas concentration measuring apparatus and method |
摘要 |
A gas-concentration measuring apparatus for measuring the concentration variation of gas residing in a target region The gas-concentration measuring apparatus comprises an ultrasound-transmitter adapted to transmit an ultrasound in response to an ultrasound-generating signal having a rate of voltage change equal to or greater than a slew rate of an operational amplifier, and further adapted to output the ultrasound-generating signal. An ultrasound-receiver adapted to receive the ultrasound passed through the gas residing in the target region, and further adapted to convert the received ultrasound into an electrical signal serving as a received ultrasound signal is provided. A gas-concentration determiner adapted to input the ultrasound-generating signal and the received ultrasound signal into the operational amplifier to generate an amplified transmitting-side chopping wave and an amplified receiving-side chopping wave is further provided. The gas-concentration determiner is further adapted to compare the transmitting-side and receiving-side chopping waves independently with corresponding given threshold voltages to detect a first pair of time points when the respective chopping waves become equal to or greater than the corresponding given threshold voltages or to detect a second pair of time points when the respective chopping waves become equal to or less than the corresponding given threshold voltages. The gas-concentration determiner is further adapted to determine the concentration variation in the gas based on the pair of time points.
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申请公布号 |
US2004065139(A1) |
申请公布日期 |
2004.04.08 |
申请号 |
US20030391016 |
申请日期 |
2003.03.19 |
申请人 |
NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY |
发明人 |
KOBAYAKAWA TATSU;YAMADA HIROSHI;TODA HIDEKI;SAITOU SACHIKO |
分类号 |
G01F1/66;G01N29/00;G01N29/02;G01N29/032;G01N29/44;G01N29/48;(IPC1-7):G01N29/02 |
主分类号 |
G01F1/66 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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