The Acid Rain samples are collected in an Aerochem Metrics wet/dry precipitation collector. This instrument consists of a two-container system with a movable lid designed to expose the wet container and cover the dry container during periods of precipitation, and vice versa. (Only wet-deposition is analyzed)

A sensor mounted on the instrument reacts electrically to the onset of precipitation causing the lid to move. Heaters mounted below the sensor serve to both melt snow and ice as well as evaporate moisture from the sensing element.

Mercury Sampler

The Mercury samples are collected in a modified Aerochem Metrics wet/dry precipitation collector. This instrument consists of a two-container system with a movable lid designed to expose the wet container and cover the dry container during periods of precipitation, and vice versa.

Modifications include the downsizing of the original wet-side orifice to a 128 cm diameter and the addition of a second orifice of the same diameter. The two wet-side orifices allows for the simultaneous sampling of mercury and other metals.

The sample is removed from the collector every Tuesday and mailed to the Hg Analytical Laboratory (HAL) at Frontier Geosciences in Seattle, WA for analysis by cold vapor atomic fluorescence.

Rain Gage

A recording and non-recording rain gage are installed at each site. The opening and closing times of the sampler lid are shown on an event recorder mounted on the recording rain gage.

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