The Jerome 651 hydrogen sulfide monitoring system from Arizona Instrument is designed to provide long-term odor monitoring even in rough weather conditions. Stationed on a pole, fence or wall, multiple units can be linked to form a perimeter monitoring system. The detachable, hand-held analyzer within the unit can be used to sweep an area and help pinpoint the source of a hydrogen sulfide leak or hot-spot. 602/529-3926; www.azic.com