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.
Anticipated Results:Electronic data from sensors mounted on moving/rotating platforms will be reliably conveyed in a noise free manner, in real time, to stationary signal processing and/or data acquisition equipment. This effectively solves an old problem by using a new technology, and at the same time greatly expands the capability of existing real time sensors and opens the possibilities for new ones. Improved accuracy in sizing particles will also result since relative velocity will be known. Also, this system will open up new possibilities for data acquisition in other fields when studying moving bodies such as rotating shafts, mechanisms, etc.
