초록 ▼

Apparatus is provided which permits highly accurate remote measurement of methane gas concentrations even in daylight through the use of an extremely narrow spectral filter centered on the Q-branch of the methane absorption band at 3.3 microns and through the use of cooperating comparison channels w

Apparatus is provided which permits highly accurate remote measurement of methane gas concentrations even in daylight through the use of an extremely narrow spectral filter centered on the Q-branch of the methane absorption band at 3.3 microns and through the use of cooperating comparison channels with digital processing for real time correction of data to compensate for surface temperature, atmospheric temperature and atmospheric water absorption factors.

대표청구항 ▼

Apparatus for accurate remote monitoring of the concentration of a target gas, which includes; first and second gas filter correlation channels both operating at a first spectral wavelength and each having an output terminal; differential amplifier means having first and second input terminals coupl

Apparatus for accurate remote monitoring of the concentration of a target gas, which includes; first and second gas filter correlation channels both operating at a first spectral wavelength and each having an output terminal; differential amplifier means having first and second input terminals coupled to respective ones of said output terminals of said first and second gas filter correlation channels for producing a first output signal which represents the target gas but requires correction for ambient conditions; a corrective channel operating at a second spectral wavelength substantially different from said first spectral wavelength for producing a second output signal representative of said ambient conditions; signal multiplying means coupled to said differential amplifier means and to said corrective channel for multiplying said first and second output signals to produce a target-gas concentration signal, said pair of gas filter correlation channels and said corrective channel being optically aligned to receive radiant energy from a common source region; and, means to utilize said gas concentration signal.