COMPACT MONITOR FOR AIRBORNE CARBON DIOXIDE MEASUREMENTS ELTRON RESEARCH&DEVELOPMENT PROPOSES THE DEVELOPMENT OF A LIGHTWEIGHT, BATTERY-POWERED INSTRUMENT FOR ACCURATELY AND RAPIDLY MONITORING THE LOCAL CONCENTRATION OF CARBON DIOXIDE (CO2) IN THE ATMOSPHERE. IN OUR PHASE I PROGRAM, AN ADVANCED CO2 ANALYZER WILL BE DEVELOPED WITH A NOVEL OPTICAL SENSOR EMPLOYING A SAMPLE CONCENTRATOR IN CONJUNCTION WITH SINGLE-BEAM, DUAL-WAVELENGTH INFRARED MEASUREMENTS. THE PROPOSED MONITOR WILL UTILIZE A THIN, IR TRANSPARENT FILM TO SELECTIVELY AND REVERSIBLY CONCENTRATE CO2 FOR ENHANCED DETECTION. THE FILM'S HIGH PARTITIONING COEFFICIENT WILL ENABLE A SHORT PATHLENGTH AND LOW POWER REQUIREMENTS WHILE ACHIEVING THE ACCURACY, RESPONSE TIME, AND DETECTION LIMITS NECESSARY FOR AIRBORNE ATMOSPHERIC MONITORING. PHASE I OF THIS PROJECT WILL ACCOMPLISH EVALUATION OF A BREADBOARD SYSTEM IN THE LABORATORY; WE ANTICIPATE A TRL OF 4 BY THE END OF PHASE I. BY THE END OF THE PHASE II PROGRAM, A PROTOTYPE INSTRUMENT WILL BE BUILT WITH 0.1 PPM RESOLUTION IN A BACKGROUND OF CA. 385 PPM,<10 S RESPONSE TIME, 800 MW POWER REQUIREMENTS, AND 250 G TOTAL WEIGHT. THE CO2 ANALYZER, WHICH WILL BE OF REDUCED SIZE AND SIGNIFICANTLY MORE COST-EFFEECTIVE THAN THE CURRENT STATE-OF-THE-ART, WILL BE SUITABLE FOR USE ON UNMANNED AERIAL VEHICLE AND BALLOON PLATFORMS.