The fluorescent technique is well recommended for in situ water vapor measurements in the upper troposphere, stratosphere and mesosphere on board balloons, highaltitude aircrafts and rockets. New version of the balloon optical fluorescent hygrometer (FLASH-BM) is presented. Special attention is devoted to the calibration procedures, stability, accuracy and precision of the flight instrument. Ne...

This paper presents a low-frequency square-wave drive, consisting of a single high voltage converter, an ac lamp ignition circuit, current control devices and a single backlight controller, capable of driving an arbitrary number of parallel cold cathode fluorescent lamps (CCFLs) with independent accurate lamp current regulation. Key to the architecture is a proposed capacitive coupling approach...