THE INCREASING OF SENSITIVITY OF MEASURING GAS CONCENTRATIONS USING THE METHOD OF COMPOSITE PARAMETERS
The sensitivity and accuracy increasing problems of optical-absorption methane concentration measuring were reviewed. A method for noise compensation and its hardware implementation in the output signal of the primary optoelectronic transmitter was proposed. To increase the measuring device sensitivity is necessary to increase the measuring base length. As shown by experimental investigation taking into account the optical system adjusting difficulties to ensure radiation source alignment and detector, it is recommended to limit the optical channel length to the base (100-150) mm. Using the proposed compensation method on the basis of the noise component parameters in the primary optoelectronic converter output signal and its hardware implementation can reduce the basic error amount of measurement to that approximately doubles the methane concentration measuring sensitivity.