System and method for identifying and characterizing fluids in a vessel

Abstract

A method and system are disclosed for using time domain reflectometry to determine the identity of a fluid in a vessel. The method includes transmitting an interrogation pulse into a vessel containing a fluid, receiving a reflection of the interrogation pulse off of a transition boundary, characterizing the properties of the reflection, where the properties include polarity, slope, phase, and amplitude, and comparing the properties of the reflection to a reference boundary transition signature.

We claim: 
     
         1 . A method of determining the identity of a fluid in a vessel, comprising the steps of:
 transmitting an interrogation pulse into a vessel containing a fluid;   receiving a first reflection of the interrogation pulse off a first transition boundary;   characterizing a property of the first reflection, where the property includes at least one of the group consisting of polarity, slope, phase, and amplitude; and   comparing the property of the first reflection to a reference boundary transition signature.   
     
     
         2 . The method of determining the identity of a fluid in a vessel of  claim 1 , wherein the reference boundary transition signature comprises an entry in a boundary transition signature table. 
     
     
         3 . The method of  claim 2 , further comprising the step of assigning a correlation value to the first reflection of the interrogation pulse and the signature boundary transition. 
     
     
         4 . The method of  claim 1 , further comprising the steps of:
 receiving a second reflection of the interrogation pulse off of a second transition boundary;   measuring the time between receiving the first reflection and receiving the second reflection;   calculating a derived characteristic of the fluid located between the first transition boundary and the second transition boundary based upon the time between receiving the first reflection and receiving the second reflection; and   comparing the derived characteristic of the fluid to a reference characteristic.   
     
     
         5 . The method of  claim 4 , wherein the reference characteristic is selected as a function of temperature. 
     
     
         6 . The method of  claim 5 , wherein the derived characteristic of the fluid is the dielectric constant of the fluid, and the reference characteristic is the dielectric constant of a reference fluid. 
     
     
         7 . The method of  claim 5 , wherein the derived characteristic of the fluid is the propagation velocity of an electromagnetic pulse in the fluid, and the reference characteristic is the propagation velocity of an electromagnetic pulse in a reference fluid. 
     
     
         8 . The method of  claim 5 , wherein the derived characteristic of the fluid is the impedance of the fluid, and the reference characteristic is the impedance of a reference fluid. 
     
     
         9 . The method of  claim 5 , wherein the steps of transmitting an interrogation pulse and receiving the first and second reflection of the interrogation pulse are performed using time domain reflectometry. 
     
     
         10 . The method of  claim 4 , wherein the derived characteristic is normalized according to a reference temperature. 
     
     
         11 . A system for determining the identity of a fluid in a vessel, comprising:
 a transmitter configured to transmit an interrogation pulse into the vessel;   a receiver, configured to receive reflected portions of the interrogation pulse;   an electronics unit in communication with said transmitter and said receiver, the electronics unit configured to transmit interrogation pulses to the transmitter and receive reflections from the receiver for time domain reflectometric measurement of the fluid;   a memory; and   a processor in communication with the electronics unit and the memory, the processor configured by the memory to perform steps comprising:
 receiving a first reflection of the interrogation pulse off of a first transition boundary; 
 characterizing a property of the first reflection, where the property includes at least one of the group consisting of polarity, slope, phase, and amplitude; and 
 comparing the property of the first reflection to a reference boundary transition signature. 
   
     
     
         12 . The system of  claim 11 , wherein the reference boundary transition signature comprises an entry in a boundary transition signature table. 
     
     
         13 . The system of  claim 11 , wherein the processor is further configured by the memory to perform a step comprising assigning a correlation value to the reflection of the interrogation pulse and the signature boundary transition. 
     
     
         14 . The system of  claim 11 , wherein the processor is further configured to perform the steps of:
 receiving a second reflection of the interrogation pulse off of a second transition boundary;   measuring the time between receiving the first reflection and receiving the second reflection;   calculating a derived characteristic of the fluid located between the first transition boundary and the second transition boundary based upon the time between receiving the first reflection and receiving the second reflection; and   comparing the derived characteristic of the fluid to a reference characteristic.   
     
     
         15 . The system of  claim 14 , wherein the reference characteristic is selected as a function of temperature. 
     
     
         16 . The system of  claim 15 , wherein the derived characteristic of the fluid is the dielectric constant of the fluid, and the reference characteristic is the dielectric constant of a reference fluid. 
     
     
         17 . The system of  claim 15 , wherein the derived characteristic of the fluid is the propagation velocity of an electromagnetic pulse in the fluid, and the reference characteristic is the propagation velocity of an electromagnetic pulse in a reference fluid. 
     
     
         18 . The system of  claim 15 , wherein the derived characteristic of the fluid is the impedance of the fluid, and the reference characteristic is the impedance of a reference fluid. 
     
     
         19 . The system of  claim 15 , wherein the steps of transmitting an interrogation pulse and receiving the first and second reflection of the interrogation pulse are performed using time domain reflectometry. 
     
     
         20 . The system of  claim 14 , wherein the derived characteristic is normalized according to a reference temperature.