APPARATUS FOR MONITORING THE OPERABILITY OF AN ELECTROCHEMICAL SENSOR

摘要

An apparatus for monitoring the status of an electrochemical sensor includes a measuring device for monitoring various electrical characteristics of the sensor and a processor for comparing such electrical characteristics to pre-determined values. The apparatus signals the operator when such characteristics deviate a pre-determined amount from a set point thereby signaling a failure of the sensor. Sensors for which the present invention is applicable include concentration sensors such as those used for quantifying the concentration of elements in molten metal samples. The electrical characteristics that are measured include AC impedance or conductance, DC resistance or conductance, and the EMF output of the sensor. Such measured characteristics can also be compared to calculated values by imposing temperature perturbations into the sample being tested.