Method and apparatus for drawing and conditioning samples of subterranean water, especially for determining the quantity of dissolved gases therein, and their use in the field of bacterial analysis

摘要

In order to draw a sample of subterranean water especially with the aim of measuring the quantity of dissolved gases therein at the drawing depth, the present invention proposes a system for opening the sampling bottle (E) which is at the same time simple, reliable and compact to be implemented in bore holes of a few inches diameter and reaching a maximum depth of 300 m. This system uses a head (C) for control, preferably pneumatic, allowing monitoring from the surface of the coincidence of a lateral orifice (55) of a movable cylinder (5) of the head (C) with the opening (75) of a channel within the stationary piston unit (7) communicating with the bottle (E). In this way the bottle (E) can be opened and closed at the drawing depth so that the water sample collected remains practically always at the corresponding hydrostatic pressure. The head (C) is furthermore disposed beneath the bottle (E) so as to trap all the dissolved gases despite their transient passage into a gaseous phase at the moment of their entry into the bottle (E). Finally the pipe (9) for conveying the fluid actuating the head (C) passes through the bottle (E) so that the bulk of the drawing apparatus is reduced to a minimum. This apparatus is completed by a laboratory unit for subsequent conditioning of the sample drawn and returning it to a lower pressure. This can subsequently also be used for analysis of the bacterial flora. In the scope of that of the dissolved gases however, an advantageous method of drawing and conditioning is moreover made known. IMAGE