Direct resistance measurement corrosion probe

Abstract

A direct resistance measurement probe for measuring corrosion levels and material loss. The probe includes a hollow body having a resistive element that is exposed to the environment. The probe can have an internal or external power source that is electrically connected to the resistive element. A meter measures the electrical resistance of the resistive element providing data from which corrosion rates may be ascertained. A temperature sensing device measures the temperature of the resistive element. A pressure sensing device measures the pressure of the environment that the resistive element is subjected to. The probe does not use a comparative or ratiometric reference element.

1 . A probe for estimating loss of a metal exposed to an environment, comprising: 
 (a) a receiver having a first and second end, and an internal flow passage;    (b) a resistive element disposed within the receiver, substantially surrounding the internal flow passage, wherein a surface of the resistive element is exposed to the internal flow passage, and the resistive element has a similar or identical composition to the exposed metal;    (c) a power source electrically connected to the resistive element;    (d) a meter for measuring the electrical resistance of the resistive element;    (e) a temperature sensing device for measuring the temperature of the resistive element disposed proximally to the resistive element;    (f) a memory for storing resistance and temperature data; and    (g) control means for applying an electric current and potential across the resistive element, receiving the output data of the resistance meter, receiving the output data of the temperature sensing device, and storing said data into the memory wherein the resistance data is associated with the temperature data;    (h) wherein said probe does not use a comparative reference element.    
   
   
       2 . The probe of  claim 1  wherein the resistive element is comprised of a circular electrically conductive metallic element having known dimensions.  
   
   
       3 . The probe of  claim 1  wherein the temperature measuring device is disposed proximally to the resistive element.  
   
   
       4 . The probe of  claim 1  further comprising a pressure sensor exposed to the environment for measuring the pressure of the particular environment.  
   
   
       5 . The probe of  claim 1  wherein the control means comprises a compact electrical circuit comprising a resistance measurement circuit, a temperature measurement circuit, a pressure measurement circuit, which is operatively connected to, or comprises, the memory.  
   
   
       6 . The probe of  claim 5  wherein the compact electrical circuit comprises a microchip.  
   
   
       7 . The probe of  claim 1  wherein the receiver defines a lateral opening through which the resistive element may be inserted.  
   
   
       8 . The probe of  claim 7  wherein the receiver is cylindrical and the resistive element is circular.  
   
   
       9 . The probe of  claim 1  wherein the receiver is formed from a receiver body and receiver flange, and the resistive element is disposed between the receiver body and the receiver flange.  
   
   
       10 . The probe of  claim 1  wherein the receiver is sealed in a fluid-tight manner to isolate the internal flow passage when the resistive element is installed.  
   
   
       11 . The probe of  claim 1  wherein the first and second ends of the receiver are adapted to attach to tubular pipes.  
   
   
       12 . The probe of  claim 11  wherein the first and second ends are threaded or comprise an attachment flange.