Environmental hazard detector using reflected radiation is at distance from object under examination e.g. tree

摘要

The detector consists of a stimulating light source such as a chopped semiconductor laser diode or a gas discharge lamp and two or more spectrally selective semiconductor photodiodes (6) as receivers. These receive signals from the object being examined e.g. a tree through short or long-pass filters (5). Signals are then transmitted to the evaluation processor (9) through a load amplifier (7). The detector is directed from a distance at the object. This may be a solid, fluid or gas e.g. chlorophyll, algae, bacteria, photosynthesis products. The filters to the receivers can be changed according to the nature of the substances being sought. The system is simple and easily portable.