APPARATUS AND METHOD FOR MEASURING NITROGEN OXIDE IN ATMOSPHERIC AIR OR EXHAUST GAS USING COLORIMETRY

摘要

PURPOSE: An apparatus and method for measuring nitrogen oxide is provided to simultaneously monitor densities of NO and NO2 of ppb level in an accurate and inexpensive manner. CONSTITUTION: An apparatus comprises a measurement unit(100) including a filter paper sensor coated with a reagent which develops color through the reaction with NO2, a sensor holder(110) for supporting the filter paper sensor to be positioned at the center, a first photo diode for radiating light to the filter paper sensor, a second photo diode(122) for measuring residual light after absorption to the filter paper sensor, a gas feed pipe(123) having a space for diffusion of gas, and an outlet pipe(124) for evacuating gas from the space of the gas feed pipe; a display unit(200) including an amplifier(210) for amplifying signals regarding the amount of NOx measured by the second photo diode of the measurement unit, and a display(220) for displaying the signal amplified by the amplifier; and an outlet unit(300) including a flow meter(310) and a pump(320) for permitting gas containing NOx to enter the measurement unit and exhausts from the measurement unit.