A new design of equilibrator to monitor carbon dioxide in highly dynamic and turbid environments

A new design of equilibrator for carbon dioxide monitoring in natural water s is described. It consists in a vertical tube filled with marbles through which water is flowing while equilibrating with a closed air circuit. It of fers several advantages compared with classical equilibrators, among which is a fast response time (half-life constant approximate to 30 s) and the po tential to work in very turbid water. The proposed equilibrator is of parti cular interest to monitor carbon dioxide in coastal ecosystems, such as est uaries, which are known to be turbid and highly dynamic. Two performance te sts and some field results are presented to illustrate the efficiency of th e proposed system. (C) 2001 Elsevier Science Ltd. All rights reserved.