DESIGN OF MEMBRANE-COVERED POLAROGRAPHIC GAS DETECTORS

Membrane-covered polarographic gas detectors are designed by employing the relationships between their design constraints, specifications, and performance parameters. The application of the detector determines the functional dependence between specificity, sensitivity, time rate of response, and wearout time. Specificity is established by the electrochemical characteristics of the detector cell. Sensitivity is determined by the membrane material and its thickness. Time rate of response characteristics are determined by the properties of the electrolyte reservoir and the membrane and the internal geometrical design of the detector. The detector can wearout by several modes which depend upon the application. Wearout by depletion of the electrolyte solvent medium is the most common. Temperature response characteristics can be established by signal temperature compensation and active thermal control. Total gas pressure, humidity, and shock and vibration also affect the detector performance by altering its parametric relationships. © 1969, American Chemical Society. All rights reserved.