Ground-water sampling probe

摘要

A probe has a filter (8) in its wall connected to the pump chamber (11) by a channel (9) containing a spring-loaded suction valve (10). A riser (12) is connected via a pressure valve (13) to the sampler pipe (15). Inert gas e.g. nitrogen is fed under pressure via lines (17,18,20). The cleaning valve (19) remains closed until the pressure valve (10) opens. Gas pressure prevents ground water from entering the filter (8). Shutting off gas pressure allows ground water to enter the pump chamber (11) for delivery to the surface. Demineralised water delivered through the line (17) cleans the probe in situ.