Summary form only given, as follows. The results of tests on a new method for improving the performance of membrane-covered polargraphic oxygen sensors are presented. The technique known as chronoamperometry or, more commonly, 'pulsed', can be applied to the usage of polargraphic oxygen sensors. The technique offers the advantage of greatly reducing the amount of oxygen consumed from the sample during the process of making a measurement. This in turn greatly reduced the sensor's sensitivity to fouling and variations in sample flow rate. Secondary benefits include long-term stability and extended service because of the very short duty cycle. The effect of fouling was simulated by doubling the membrane thickness; the steady-state current was halved, but the current measured at 1 s was unaffected. The effect of a transition from high flow rate to no flow produced a 28-43% decrease in steady current, depending on whether membrane thickness was 1. 0 or 0. 5 mil respectively, but the current measured at 1 s declined by only 0. 3-1. 2%.
ASJC Scopus subject areas