IMPROVED REAL-TIME SIZE ANALYZER FOR INHALABLE PARTICLES

PYROLYSIS-PLUS-SURFACE IONIZATION (PPSI) IS A TECHNIQUE WHEREIN A PARTICLE IS IMPACTED ONTO A HOT CATALYTIC SURFACE WITH HIGH WORK FUNCTION, WHERE THE PARTICLE DECOMPSES AND THOSE OF ITS ATOMS WITH LOW IONIZATION POTENTIALS LEAVE THE SURFACE AS A BURST OF POSITIVE IONS WHICH CAN BE DETECTED ASA VOLTAGE PULSE. THIS RELATIVELY NEW TECHNIQUE, WHICH HAS ONLY BEEN USED IN PROTOTYPE DEVICES TO DATE, IS FAR MORE SENSITIVE THAN OPTICAL METHODS IN MANY CASES. IT IS HEREIN PROPOSED THAT THIS DETECTION TECHNIQUE BE ADAPTED AND TESTEDAS A UNIVERSAL PARTICLE COUNTER TO AUTOMATE AND IMPROVE THE SENSITIVITY OF A DEVICE WHICH SEPARATES PARTICLES BY SIZE. CONCURRENT WITH THIS EFFORT, AN ELECTROSTATIC MOBILITY ANALYZER COULD ALSO BE IMPROVED BY USING FIELD CHARGING TO EXTEND THE PARTICLE SIZE UPWARD INTO THE RESPIRABLE RANGE, AND BY USING FIRST-ORDER FOCUSING PRINCIPLES TO REDUCE MECHANICAL STABILITY REQUIREMENTS. THE RESULT WILL BE A REAL-TIME PARTICLE SIZE ANALYZER IN THE INHALABLE RANGE. EMPHASIS OF THIS PROJECT WILL BE TO DEVELOP A DEVICE SUITABLE FOR MEDICAL STUDIES, WORK PLACE MONITORING, AND CERTAIN PROCESS APPLICATIONS.