Proportional analyser for nitrate concentration - measures direct current flow as function of time

摘要

By choosing optimum valves for the various parameters such as speed of flow and sampling frequency the current detected can be related linearly with the concentration. The liquid to be measured flows in a section of flexible or rigid tube (1) on which two platinum electrodes (2) are attached parallel to each other and parallel to the flow. The electrodes are attached to the poles of a continuous current source (3) and the current intensity is measured on a microammeter (4), and recorded (5). A digital recorder (6) can also be used when linear correlation exists between the current as a function of time and the concentration.