| 摘要 |
PURPOSE:To detect at a high sensitivity the energy of infrared rays coming into a detector of a non-dispersion type infrared ray gas analyzer permeating through gases, etc. to be measured by measuring the amplitude of speed of Helmholtz resonance by utilizing Doppler effect. CONSTITUTION:As shown by arrows, gases for measuring including an ingredient to be measured are introduced into a measuring cell 3 from an inlet 3a and sent out through an outlet 3b, and a specified standard gas is filled up in a standard cell 4. Supersonic signals generated by a supersonic oscillator 9a propagate through gas inside a Helmholtz resonator 8 and are received by a supersonic receiver 9b. In the Helmholtz resonator 8, the velocity of gas caused by the expansion of gas under standard condition considerably differs from that of the gas under measuring condition, and supersonic signals generated from the supersonic oscillator 9a become Doppler frequencies corresponding to the difference of velocity of gas and they are received by the supersonic receiver 9b. This Doppler frequency is processed by a signal processing circuit and converted into the density of gas of the ingredient to be measured. |
