发明名称 |
Automatic calibration circuit for gas analyzers |
摘要 |
A device for measuring the concentration of a radiation-absorbing agent in a gas mixture features circuitry for automatically calibrating the device according to a reference gas mixture. An error detector compares the transmittivity of the reference gas mixture, as determined by a photometer, to a reference current determined by Beer's Law. The error signal thus generated is provided to a sample and hold circuit which includes a digital counting circuit and a digital-to-analog converter. The output of the sample and hold circuit causes the drive current supplied to the radiation source of the photometer to be adjusted to automatically calibrate the device.
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申请公布号 |
US4167665(A) |
申请公布日期 |
1979.09.11 |
申请号 |
US19770847408 |
申请日期 |
1977.10.31 |
申请人 |
DASIBI ENVIRONMENTAL CORPORATION |
发明人 |
JOHNS, ROBERT K.;HOUSTON, OWEN M.;FRICK, GENE |
分类号 |
G01N21/27;G01N33/00;(IPC1-7):G01J1/32;G01N21/26;G05D25/02 |
主分类号 |
G01N21/27 |
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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