A SHORT RANGE OPTICAL DATA LINK FOR ROTARY SAMPLERS WHICH PROVIDE CONTINUOUS REAL TIME DATA

THE FEASIBILITY OF LOW COST REAL TIME SENSORS CAPABLE OF DETECTING AGRICULTURAL SPRAY DRIFT (JORDEN, 1993) AND SOLID AIRBORNE PARTICLES (JORDEN 1992) HAS BEEN DEMONSTRATED. WHILE THESE DEVICES ARE VERY EFFECTIVE IN THEIR PRESENT FORM, THEY CAN BECOME MORE ACCURATE AND VERSATILE IF THEY ARE ABLE TO SAMPLE LARGER VOLUMES OF AIR. THIS CAN BE ACCOMPLISHED BY ROTATING THE SENSORS THROUGH THE AIR AT A HIGH VELOCITY RELATIVE TO THE WIND CARRYING THE AEROSOLS, THUS TAKING THE SENSOR TO THE PARTICLES, RATHER THAN WAITING FOR THEM TO CONTACT IT. ELECTRONIC CONNECTION BETWEEN A ROTATING OR MOVING PLATFORM NORMALLY EMPLOYS SLIP RINGS WHICH ARE WELL KNOWN FOR SPURIOUS NOISE, WEAR, AND INTERMITTENT CONNECTIONS ARISING FROM CONTAMINATION. THIS APPROACH AVOIDS THE USE OF SLIP RINGS BY USING NEW TECHNOLOGY; A LOW-COST, LARGE SCALE INTEGRATED CIRCUIT (LSI) INFRA-RED DATA LINK (TRANSMITTER AND RECEIVER), WHICH IS CONTROLLED BY A LOW COST, SUB-MINIATURE, STAND ALONE MICROCONTROLLER TO PROVIDE CONTROL OF THE TEST PROCESS. THIS ALLOWS ON-PLATFORM SIGNAL PROCESSING, ANALOG TO DIGITAL CONVERSION, AND DATA CODING. THE LIKELIHOOD OF DETECTING A SINGLE PARTICLE, IN LOW CONCENTRATIONS, IMPROVES BY AT LEAST A FACTOR OF TEN IF DEPLOYED IN A NON-PASSIVE MANNER.