Fluid presence and qualitative measurements by transient immitivity response

Abstract

An apparatus and method for obtaining a measurement of various qualities of an electrochemical cell ( 12 ). The apparatus includes first ( 9 ) and second ( 10 ) electrodes and an excitation source ( 8 ) for providing a time varying excitation voltage to the first electrode ( 9 ). The excitation voltage ( 8 ) is switched between two voltage levels with the first and second voltages alternately applied to the first electrode for predetermined times. An external capacitance (Cout) is connected between the second electrode ( 10 ) and ground. The apparatus is capable of determining the time related rates at which electrical charge is transferred from the first electrode ( 9 ) to charge the external capacitance (Cout). These rates, here termed Transient Immitivity Response (TIR), may be provided as a digital or analog output ( 11 ).

1 - 26 . (canceled)  
   
   
       27 . An apparatus for obtaining a transient immitivity response for a fluid, comprising: 
 a first electrode and a second electrode, the first and second electrodes being spaced apart from each other and both in contact with the fluid;    an excitation source for providing a time varying excitation voltage to the first electrode, the excitation voltage being capable of being switched between a first defined voltage level and a distinct second defined voltage level, the first and second voltage levels being alternately applied to the first electrode for specific time periods;    a capacitance located between the second electrode and an electrical or circuit ground, the ground having a defined ground voltage;    a voltage detector for detecting a sensed voltage at a predetermined location with respect to the apparatus, the sensed voltage being proportional to electrical charges conducted through the fluid from the first electrode to the second electrode as a consequence of the excitation voltage applied to the first electrode, and the voltage detector capable of determining the sensed voltage at one or more time intervals; and    a timing device for determining one or more time intervals between the switch in first and second defined voltage levels wherein the one or more time intervals can be correlated with the sensed voltage at each interval and each sensed voltage per time interval measures a rate representing the transient immitivity response.    
   
   
       28 . A method for obtaining a transient immitivity response, comprising the steps of: 
 a) contacting a fluid with a first electrode and a second electrode, the first and second electrodes spaced apart from each other;    b) applying an excitation voltage to the first electrode and switching the excitation voltage between a first defined voltage level and a distinct second defined voltage level, the first and second defined voltage levels being alternately applied to the first electrode for specific time periods;    c) providing a capacitance between the second electrode and an electrical or circuit ground, the ground having a defined ground voltage;    d) detecting a sensed voltage resulting from the excitation voltage applied to the first electrode by means of a series resistance wherein the sensed voltage is proportional to the electrical charges conducted through the fluid from the first electrode to the second electrode as a consequence of the excitation voltage applied to the first electrode;    e) determining one or more rates of change in the sensed voltage per time interval, such rate or rates representing the transient immitivity response of the fluid; and    f) providing the measured rate or rates representing the transient immitivity response as a digital or analog output.