Abstract: The present invention is directed to a system for identifying and managing corrosion and methods related thereto. In particular, the invention provides a system for identifying and managing the structural corrosion potential for an assembly by measuring a “Relative Corrosion Index” (“RCI”).

Abstract: Methods of deriving the cumulative maximum localized corrosion rate and cumulative localized corrosion rate factor for corrosion monitoring using coupled multielectrode array sensor probes are disclosed. Compared with maximum localized corrosion rate, which is derived from the corrosion rate on any of the electrodes of a probe that has the highest corrosion rate at a given moment of time, cumulative maximum localized corrosion rate is derived from the corrosion rate of the electrode that has been corroded the most in a given time period. The cumulative maximum localized corrosion rate is directly related to the corrosion damage (maximum localized corrosion depth); the maximum localized corrosion depth equals the integration of the cumulative maximum localized corrosion rate. Cumulative maximum localized corrosion rate should be used to evaluate the localized corrosion effect on metal damage.

Abstract: The bounding corrosion rate is measured with a coupled multielectrode array sensor by decoupling a select number of anodic electrodes on the sensor from the coupling joint. In doing so, all or most of the electrons produced on the anodic electrode that remains connected to the coupling joint are forced to flow to the coupling joint and are thus measured. Because of the large number of electrodes on a multielectrode array sensor, one of them may become contaminated by foreign materials during the measurements or polishing process. The effect of such an electrode on the performance of the sensor can be eliminated by automatically disconnecting it from the coupling joint.

Abstract: A sensor for monitoring and testing for both possible fractures and corrosion in structural elements is disclosed. A frangible material layer including a thin breakable conductor sense loop and a resilient material layer including a conductive corrosion sense loop bonded on top of the frangible layer form an assembly which is bonded to a structural element to be tested. Portions of the conductive corrosion sense loop are exposed through weep holes in the resilient material layer. A fracture in the bonded structural element induces a disruption in both the frangible membrane and the thin breakable conductor sense loop and corrosion of the conductive corrosion sense loop changes its electrical properties. Measured electrical property changes of the disrupted conductor sense loop and/or the conductive corrosion sense loop reveal possible damage. Both sensor layers may utilize a single shared wireless communications tag to couple to an electrical measuring device.

Abstract: A system or method of analyzing a conductive member for the presence an anomaly. A conductive pipe member is analyzed for the presence an anomaly the electromagnetic properties of which are non-linear. The electromagnetic properties of the pipe member at the anomaly are altered by applying a direct current perturbation signal to the pipe member. At least one test source signal is applied to a first test location on the pipe member remote from the anomaly to cause the at least one test source signal to travel along the pipe through the anomaly. At least one test return signal associated with the at least one test source signal traveling through the anomaly is detected. The at least one test return signal is analyzed for characteristics associated with the anomaly.

Abstract: The cathodic protection monitor includes a CPU that reads, digitizes and stores analog current and voltage signals which are supplied from the DC output of the rectifier and are indicative of the effectiveness thereof. The monitor includes an ISM band transceiver and antenna by which the CPU is polled and from which packets of stored data are transmitted to a data collector at an overhead airplane or nearby motor vehicle for retransmission and analysis by the pipe owner or maintenance crew. Synchronized timing signals are supplied (from the National Bureau of Standards) to a stable auxiliary clock by way of a WWVB transceiver and antenna so that a plurality of cathodic protection rectifiers can be turned on and off at the same time as may be required to compile ground voltage readings along the pipeline as part of a government-mandated survey.

Abstract: Simultaneous determination of general corrosion and localized corrosion rate measurements is achieved with polarization applied by the electrodes themselves rather than externally applied polarization. Two or more working electrodes may be galvanically coupled. A localized pitting corrosion event on one of the electrodes will lead to a potential transient. The area within the potential transient is measured with the baseline being the initial starting potential. This gives localized corrosion as a function of time. The relationship Rp=?V/?I is calculated, where Rp is the polarization resistance of the working electrodes and is a measure of generalized corrosion rate.

Abstract: A method for testing anticorrosion performance of an aqueous protective fluid by immersing a testing electrode comprising a plurality of individual electrodes insulated from and spaced with respect to one another into an aqueous protective fluid; immersing a reference electrode into the aqueous protective fluid at a predetermined distance from the testing electrode; connecting an Ohmmeter sequentially between each of the individual electrodes and the reference electrode to measure a plurality of electrical resistances between each of the individual electrodes and the reference electrode whereby obtaining a distribution of resistances. The distribution of resistances defines the anticorrosion performance of the aqueous protective fluid.

Abstract: Process for evaluating the corrosive effect of a refinery feedstock on the metallurgy of one or more refinery processes, by (i) providing a plurality of refinery feedstocks and/or a plurality of fractions of one or more refinery feedstocks, (ii) providing an array having a plurality of metal samples representative of metallurgy present in a refinery, (iii) contacting each of the plurality of metal samples with one or more of the refinery feedstocks or fractions under non-static conditions, and (iv) determining the corrosive effect of the feedstock and/or fraction on the metal sample.

Abstract: A thin and narrow electrical resistance corrosion sensor defines measurement, reference and check resistors as abutting serially disposed portions of a thin strip-like metal resistance element, such as a carbon steel or ductile iron element, having metallurgical properties which match those of a corrodible structure of interest such as a pipeline buried in the ground. The resistance element is bonded to a thin, long and narrow nonconductive structural substrate to which is also bonded a flat wire harness which includes conductors connected to the ends of the resistance element and to selected locations of the element between its ends. The resistance element, the substrate, and the wire harness and its connections to the resistance element are encapsulated by a nonconductive protective coating except over the area of the measurement resistor so that such resistor can be exposed to the adjacent environment. The sensor can be used with conventional corrosion measurement instruments.

Abstract: A circuit for preventing corrosion of a contact, includes an input terminal, a signal line, a switch, an impedance element, and a comparator. The input terminal is to be connected to the contact, which is outside the circuit. The signal line is connected to the input terminal. The switch is connected to the signal line. The impedance element is connected to the signal line in parallel to the switch. An impedance of the switching section is smaller than that of the impedance element. The comparator compares a potential of the signal line with a predetermined potential. The switch is turned on based on a comparison result output from the comparator.

Abstract: A method of diagnosing corrosion risk of a buried pipe due to DC stray currents and/or AC voltages induced in soil employs a metal probe including a first, exposed part having a first specific resistivity, and a second, sealed reference part having a second specific resistivity. The probe is buried in the soil, and the AC current and voltage between the pipe and the probe are measured, from which the spread resistance is determined. The resistances of the first and second probe parts are determined by respectively passing first and second excitation currents through the first and second probe parts and measuring the voltages across them. The resistance measurements are stored, and the steps are repeated periodically. The corrosion of the first probe part is determined from the measurements according to an algorithm, and the pipe corrosion risk is diagnosed from an empirical combination of the corrosion of the first probe part, the spread resistance, and the AC voltage measured.

Abstract: A sensor device for monitoring and testing for potential corrosion of structural elements is disclosed. A membrane including a thin conductor sense loop within it may be disposed near a structural element to be monitored. Measured changes in the electrical properties of the conductor sense loop reveal corrosion of the conductor and can indicate potential corrosion in the structural element. The sensor may also be implemented as a gasket. Connection to the sensor device may be through a connector or using a wireless reader which remotely energizes the sensor device.

Abstract: A method and apparatus for simultaneously and continuously monitoring both the general and localized corrosion of a working metallic electrode is provided, wherein a low frequency, low amplitude periodic potential excitation is used to perturb the electrode around its free corrosion potential. The potential is controlled with respect to a reference electrode by means of a potentiostat, and an auxiliary electrode used to stimulate current flow. The current response of the working electrode is monitored and analyzed continuously for general and localized corrosion activity. Means are provided for validation of the integrity of the current response to the applied potential excitation. Simultaneous and continuous outputs for both general and localized corrosion activity are also provided.

Abstract: An article includes an electrically conductive corrodible element; a device that can inject electricity at a plurality of operation frequencies into the corrodible element; and a measurement apparatus operable to measuring impedance of the electrically conductive corrodible element under various operation frequencies.

Abstract: Methods of using multihole and multiwire sensors to measure general and localized corrosion penetration rates near real time are disclosed. The multihole penetration sensor is included of multiple electrodes embedded in individual cavities that are formed by a metal whose external surface is exposed to a corrosion environment. The distance between the inner surface and the external surface of the cavities (wall thickness) varies from one cavity to the other. The electrical resistance or current between each of the electrodes and a common electrode exposed to the same corrosion environment changes significantly when the wall of the cavity in which the electrode resides is perforated by corrosion and the corrosion medium is in contact with the electrode. The corrosion penetration rate is calculated by dividing the wall thickness of the different cavities by the time it takes to penetrate these cavities.

Abstract: An apparatus for preventing corrosion of a contact includes a detection conducting path connected to the contact, a variable impedance unit and a comparing and switching unit. The variable impedance unit is connected to the detection conducting path. The variable impedance unit is switchable between (i) a first impedance used for passing a corrosion prevention current into the detection conducting path and (ii) a second impedance through used for passing a current, which is used for detecting a connection state of the contact, into the detection conducting path. The first impedance is lower than the second impedance. The comparing and switching unit compares a detected value with a corrosion threshold, compares the detected value with a restoration threshold and switches the variable impedance unit based on comparing results.

Abstract: A detection system for monitoring an engineered structure includes an array of sensors disposable in a predetermined pattern on the engineered structure and disposable between a surface of the engineered structure and a protective coating substantially covering the surface. The detection system also includes a data acquisition system in communication with the array of sensors for retrieving data from the sensors. The array of sensors can provide data corresponding to at least one of a degree of cure of the protective coating, a health of the cured protective coating, and a corrosion rate of the engineered structure at each of the sensors.

Abstract: An electronic system and software program for multielectrode electrochemical devices; a multielectrode sensor for application in environments containing electrochemically active species; and a multielectrode sensor with a built-in removable large electrode. The electronic system has a large electrode connected to the coupling joint through a resistor element to adjust the potential of the multielectrodes. The electronic system, along with the software program, automatically changes the values of the coupling resistors so that the potentials of a group of electrodes or all the electrodes of a sensor are similar, or automatically disconnects malfunctioning electrodes from the coupling joints to avoid the effect of such electrodes. A variation of the electronic system uses an ammeter or a zero-resistance-ammeter to measure the coupling currents and has resistors between the electrodes and the coupling joint to reduce the transient current produced during switching.

Abstract: A corrosion sensor having a corrodible element that is corrodible in a lubricant or hydraulic oil, wherein the corrosion sensor is adapted to monitor degradation of the lubricant or hydraulic oil is disclosed.

Abstract: A corrosion monitoring device for monitoring corrosion in fluid containing systems and other equipment exposed to a corrosive environment comprising sensor elements having a composition substantially the same as the equipment being monitored, the sensor elements having a predetermined thickness for exposure to a corrosive solution of the fluid containing system. An electrical property of the monitoring device changes when corrosion penetrates through the thickness of the sensor element. A digital output device generates a first binary signal when corrosion has not penetrated through the thickness of the sensor elements, and a second binary signal when corrosion has penetrated through the thickness of the sensor elements. Multiple sensor elements may be used to provide multiple binary signals. Information from the digital outputs may be processed to provide a cumulative log of corrosion measurements.

Abstract: A process for evaluating the corrosive effect of a refinery feedstock on the metallurgy of one or more refinery processes, said process comprising: (i) providing a plurality of refinery feedstocks and/or a plurality of fractions of one or more refinery feedstocks, (ii) providing an array comprising a plurality of metal samples representative of metallurgy present in a refinery, (iii) contacting each of the plurality of metal samples with one or more of said refinery feedstocks or fractions under non-static conditions, and (iv) determining the corrosive effect of said feedstock and/or fraction on the metal sample.

Abstract: A circuit arrangement for a line test and for feeding a corrosion protection current into a two-wire line comprises a controllable ramp generator for producing a ramp voltage, at least one first test impedance to be connected to a first line of a two-wire line, at least one second test impedance to be connected to a second line of the two-wire line, at least one first and second controllable switches for connecting the ramp voltage to the first and second test impedances, and a programmable control device for controlling the ramp generator and the first and second controllable switches in such a way so that the ramp voltage is coupled to the two-wire line in order to produce a corrosion protection current. The control device switches at least one of the first and second test impedances to the respective of the first and second lines for a line test.

Abstract: A method for testing effectiveness of a cathodic protection device configured to apply at least one voltage across an underground structure and a reference point is described. The method includes providing a sample of the material from which the underground structure is fabricated, placing the sample proximate the underground structure, electrically connecting the sample to the underground structure through a switch, operating the switch at predetermined intervals, and measuring electrical characteristics of the sample at intervals based at least partially on the predetermined intervals and a position of the switch.

Abstract: A method of measuring localized corrosion, using a multi-electrode array sensor. The method eliminates the effect of internal current in corroded electrodes, and thus provides a more accurate corrosion measurement. In one embodiment, the potential of a common node of the sensor is adjusted so that the sensor's most cathodic current is close to zero.

Abstract: A combustion chamber (4) for a gas turbine (1), the combustion chamber wall (24) of which is furnished on the inside with a lining formed of a number of heat shield elements (26), is to be designed for a particularly high level of operating safety. To this end, one or a number of temperature sensors (28) is/are located according to the invention between combustion chamber wall (24) and heat shield elements (26).

Abstract: The present invention relates to a pipeline examination apparatus for Direct Current Voltage Gradient (DCVG) and Closed Interval Potential Survey (CIPS) methods. The pipeline examination apparatus of the present invention detects and analyzes at least one electrode signal while supplying an anticorrosive current to a buried pipeline by switching on and off the anticorrosive current at predetermined intervals. The pipeline examination apparatus includes a signal detection unit and a measurement unit. The signal detection unit detects the electrode signal including a DCVG electrode signal and/or a CIPS electrode signal. The measurement unit receives the electrode signal from the signal detection unit and analyzes the electrode signal. The measurement unit includes a measurement method selection unit, a control unit, a storage unit, an analysis unit and a display unit.

Abstract: Low power corrosion measurement devices are described with improved LPR, HDA, and ECN measurement capabilities in a field transmitter for online corrosion monitoring or off-line corrosion data logging.

Abstract: Low power corrosion measurement devices are described with improved signal measurement and excitation circuitry in a field transmitter for online corrosion monitoring or off-line corrosion data logging.

Abstract: Corrosion measurement devices are described with electrical isolation and intrinsic safety barriers advanced corrosion measurement in a field transmitter for online corrosion monitoring or off-line corrosion data logging.

Abstract: Low power corrosion measurement devices are described with programmable configuration for implementing one or more advanced corrosion measurement types to provide conductivity, general corrosion, and/or localized corrosion values in a field transmitter for online corrosion monitoring or off-line corrosion data logging.

Abstract: A system or method of analyzing a conductive member for the presence an anomaly. A test source signal is applied to a first test location on the elongate conductive member remote from the corrosion to cause the test source signal to travel along the pipe through the anomaly. At least one test return signal caused by the test source signal traveling through the anomaly is detected. The at least one test return signal for characteristics associated with the anomaly. Optionally, a perturbation may be applied to the elongate conductive member to place the conductive member in a perturbed state in which the electromagnetic characteristics of the conductive member at the anomaly are altered. The test source signal is applied to the first test location when the conductive member is in the perturbed stated.

Abstract: A basic electronic unit, an integrated electronic system, and the associated software program for coupled multielectrode electrochemical devices or sensors. The basic electronic unit uses different values of resistors for coupling the multiple electrodes in an electrochemical device or a sensor, so that the effective value of the coupling resistance can be dynamically changed according to the magnitude of the measured coupling current during the measurement. This feature allows the electronic unit to measure a wide range of coupling currents without compromising the principle that the coupled multielectrode electrochemical device simulates the one-piece metal behavior. The integrated electronic system uses several basic electronic units, so that it can simultaneously measure several independent multielectrode electrochemical devices or sensors that have a small number of electrodes, or measure one or more multielectrode devices or sensors that have a large number of electrodes.

Abstract: A component which is known to have particular degradation characteristics is instrumented to provide an electrical potential across a section in which a degradation is likely to occur. The potential drop across the component is then monitored to determine when, and the degree to which, the degradation occurs. Predetermined limits are established such that when the degradation level reaches a limit, the component is repaired or replaced.

Abstract: A conductivity sensor includes a sensor body having an inner surface and an outer surface. A first and a second electrode formed of a solid conducting material are positioned through the inner surface of sensor body. An epoxy resin is positioned in the inner surface of the sensor body thereby encapsulating a portion of the first and second electrode. The epoxy resin forms an active surface that exposes a first end of the first and a first end of the second electrode for conductivity measurement and forms a connector surface that exposes a second end of the first and a second end of the second electrode for electrically interfacing with a conductivity measurement circuit.

Abstract: An embeddable corrosion rate meter (ECRM) for detecting and measuring corrosion in metal and concrete structures is provided. The system comprises an electrochemical cell with at least one working electrode evenly separated from a counter electrode, wherein a separation distance between electrodes determines an electrolyte medium resistance and the electrolyte medium resistance is less than or equal to a polarization resistance.

Abstract: A corrosion coupon rack includes one or more coupon mounting devices constructed of a coupon holder receiver including a handle recess of a given diameter and an end wall, a connection conduit in communication with the handle recess through an opening in the end wall and axially aligned therewith, and locking means having open and closed positions, the locking means including a cam surface extending into the handle recess when the locking means is in the closed position; and a coupon holder including a handle insertable into the handle recess, the handle having inner and outer ends, a locking recess, and a shaft axially aligned with the handle, the shaft having a proximal end attached to the handle inner end, and a distal end adapted to releasibly attach a corrosion coupon, the shaft extending through the T-connection and into the pipe.

Abstract: A method for testing a cathodic protection system is disclosed where the system includes a cathodic protection rectifier configured to apply a voltage across a pipeline and a reference point. The method includes measuring a magnitude of an output voltage of the cathodic protection rectifier, transmitting to a site remote from the rectifier, the measured output voltage magnitude using a cellular control channel, receiving the transmitted measurement at the remote site, and using the transmitted measurement to determine whether the cathodic protection system is operational.

Abstract: A system for monitoring corrosion in metal by comparing a test sample exposed to a corrosion causing environment and a reference sample exposed to a protected environment. An AC voltage source generates a square wave signal oscillating between ground and voltage Vcc and a filter is positioned to filter the signal to produce a sine wave with no second harmonic component. A voltage-driven current source and inverting amplifier produce a current referenced to 0.5 Vcc to provide an AC current from the drive voltage driven sinusoidally and symmetrically above and below 0.5 Vcc. A transformer steps up the AC current and thereafter transmits the current through the samples to an amplifier for amplifying the current to provide outputs in a ratio representing the degree of corrosion of the reference sample. The system can operate in situ for on site measurement and uses relatively low current to permit long operation.

Abstract: A direct resistance measurement probe for measuring corrosion levels and material loss. The probe includes a hollow body having a resistive element at one end 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.

Abstract: A feedwater heater for an HRSG is provided with a monitoring unit for detecting the presence of condensation in the feedwater heater. The monitoring unit includes a dielectric band around one of the tubes of the feedwater heater near the location where the feedwater is directed into the heater and a conductive band located around the dielectric band. The unit also includes a conductivity sensor installed between a ground on the feedwater heater and the conductive element. Hot gases containing moisture pass through the feedwater heater, and if the temperature of surfaces in the region of the tube around which the dielectric and conductive bands extend drops below the dew point of the gas, an electrically conductive condensate will appear those surfaces and on the tube and will flow over the dielectric band, completing an electric circuit between the tube and the conductive band. The conductivity sensor detects this and hence detects the presence of the condensation.

Abstract: A sensor array for measuring localized corrosion based on electrochemical reactions is disclosed. The sensor has an array of electrodes that are made from the material of interest. The electrodes are electrically insulated from each other and arranged so that a small area of the electrode contacts a corrosive environment. The voltage outputs across the electrodes connected to the electrodes are measured and used as the signals to indicate localized corrosion.

Abstract: A method of monitoring or predicting corrosion using a field signature method is provided which is intended to be applicable to non-linear locations, such as bends, junctions and the like. The method includes obtaining information on a relationship which links voltage measurements, obtained for a location, between two or more electrical contacts in contact with the location at a first time and one or more other times when a current is passed through the location, to the loss of material from the location. The information on the relationship is used in a modelling process which includes the generation of a model of the location, two or more points on that location and modelling the values generated for the voltages which will be measured between the two or more points with a current applied to the location at a first and at least at a second time.

Abstract: A method and apparatus for monitoring the concentration of metal cations in a chemical solution. In a preferred embodiment, the chemical solution is a solution for derouging or passivating stainless steel. A capacitive sensor provides data indicative of the concentration of chemical components (e.g., iron or chromium) in the chemical solution.

Abstract: Wear-detection sensor has a body of electrically insulating material with an opening through which a flowable substance can pass, and one or more electrical conductors surrounding the opening and adapted to undergo a discernable change in conductivity as the insulating material is worn away by the flowable substance.

Abstract: An apparatus (1) is disclosed for monitoring the effect on a material of exposure to a fluid, and thereby monitoring the effect on a section of pipe (9) for carrying the fluid. The apparatus includes a sensor element (51) exposed to the fluid and formed as a ring of the material coaxially mounted within, but electrically insulated from, the section of pipe (9). Changes in the electrical resistance of the sensor element (51) are monitored. Preferably, the apparatus also includes a reference element (31) electrically insulated from the pipe (9), electrically connected in series to the sensor element (51) and protected from exposure to the fluid. The elements may both be made from the same material as the pipe (9) and, as they are contained within it, experience the same temperature and pressure variations as the pipe (9).

Abstract: Apparatus and methods for materials inspection using microwave sensing are disclosed. In one aspect, a system for detecting corrosion of a workpiece includes a scanning assembly having a support assembly adapted to be coupled to the workpiece, and a first translation device coupled to the support assembly. A microwave sensor is coupled to the first translation device. The first translation device is adapted to translate the microwave sensor along at least a first direction, and the microwave sensor is adapted to transmit incident microwave signals onto the workpiece and to receive reflected microwave signals reflected from the workpiece. In an alternate aspect, a system may further include a second translation device that is adapted to translate the microwave sensor along at least a second direction that is transverse to the first direction.

Abstract: The present invention relates to a method and an apparatus for measuring accumulated and instant rate of material loss or material gain of metal elements for the detection of metal deposition (material gain) caused for example during deposition of coatings used in plating processes and corrosion (material loss) caused for example in pipelines during transportation of hazardous media. The apparatus and the method provides means for measuring accumulated and instant rate of material loss or material gain by inserting a probe in a measurement environment causing a probe experience metal deposition or corrosion. Further the apparatus and the method provides means for performing a temperature independent measurement of accumulated and instant rate of material loss or material gain accomplished without use of a temperature sensor device.

Abstract: An evaluating pattern includes a conductive pattern formed on a substrate, an insulating layer which is formed on the conductive pattern, a plurality of contact holes formed in a rectangular area through the insulating layer, and a conductive material filled into the contact holes to the conductive pattern.

Abstract: An improved corrosion measurement system for determining the rate of corrosion of a fluid medium. The system is comprised of a highly sensitive excitation and amplification electronic circuitry for registering and displaying the stable and accurate measurement results. A novel current feedback amplifier maintains a constant alternating current voltage across the reference element, by simultaneously controlling the current through the serially connected reference and corroding elements, thereby keeping the corrosivity measurement independent of the probe's ambient temperature. The unique unitized electrical resistance measurement probe is also temperature stabilized using thermally bridged and balanced metallic elements; the first reference element being coated with an impermeable insulating coating, the second, the sacrificial corroding element, being fully exposed to the corrosive fluid medium.