发明名称 |
Laser scanning apparatus |
摘要 |
Apparatus for monitoring gaseous pollutants (e.g. on a chemical plant) produces two infra-red laser beams having different wavelengths (one corresponding to an absorption line of the gas to be monitored, the other being a reference) which are modulated with different frequencies or phases, and then combined into a single scanning beam. The scanning beam is continuously displaced angularly so as to scan the area to be monitored. A portion of the beam is returned to the apparatus by scattering or reflection, and is measured. By correlating this with the direction of the beam, a plan of the monitored area superimposed with a continuously updated indication of the amount of gas can be displayed e.g. on a VDU.
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申请公布号 |
US4426640(A) |
申请公布日期 |
1984.01.17 |
申请号 |
US19800184259 |
申请日期 |
1980.09.05 |
申请人 |
IMPERIAL CHEMICAL INDUSTRIES LIMITED |
发明人 |
BECCONSALL, JACK K.;CRAMP, JOHN H. W.;REID, ROBERT F.;MOORE, REGINALD C.;RYE, BARRY J.;THOMAS, ERIC L. |
分类号 |
G01N21/39;G01S17/95;(IPC1-7):G08B17/10 |
主分类号 |
G01N21/39 |
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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