Abstract: A Gated CDS Integrator (GCI) may amplify low-level signals without introducing excessive offset and noise. The GCI may also amplify the low level signals with accurate and variable gain. The GCI may include a modulator preceding an amplifier such that offset or noise present in a signal path between the modulator and a demodulator input is translated to a higher out of band frequency, and thereafter reduced by a double sampled discrete time integrator which also reduces thermal noise. The thermal noise may also be reduced by averaging the output of the discrete time integrator.

Abstract: Measurement devices, systems, and methods to measure a high field conductivity of a fluid are provided herein. The measurement device includes a fluid cell, a pair of electrodes, a voltage switch, and a measurement unit. The fluid cell is on an inclined plane to receive the fluid. The pair of electrodes are connected to the fluid cell. The pair of electrodes are spaced apart from one another to receive the fluid therebetween and positioned parallel to one another to pass an electrical current therethrough. The power unit provides a high voltage power supply to one electrode of the pair of electrodes. The measurement unit measures the electrical current that passes between the pair of electrodes through the fluid.

Abstract: An interrogation circuit for a nanowire sensor array and a method for interrogating a nanowire sensor array are provided. The circuit comprises a switch array connected to the nanowire sensor array for selectively connecting first ends of nanowire sensors of the nanowire sensor array to a reference voltage; an integration amplifier (IA) connected to second ends of the nanowire sensors at a first input of the IA and to the reference voltage at a second input of the IA, for generating an oscillating output signal clamped between first and second voltage values; wherein the switch array is further arranged for switching one of the nanowire sensors to be connected in a closed loop with the IA such that a current through said one nanowire sensor periodically charges and discharges an integration capacitor of the IA for determining a resistance of said one nanowire sensor from a frequency of the periodic charging and discharging.

Abstract: A method for controlling an induction apparatus having an induction coil. In one implementation the induction apparatus includes a capacitor that is connected in parallel with the induction coil to form a parallel resonant circuit, and also includes a switch connected in series with the parallel resonant circuit, between the parallel resonant circuit and a reference voltage. According to one method, a digital test signal dependent on the voltage in a node disposed between the switch and the parallel resonant circuit is generated, the switch is closed for a predetermined closure time and then reopened at the end of the closure time. With the switch reopened, the test signal is evaluated for a predetermined waiting time in order to determine the presence or absence of a vessel on the induction coil.

Abstract: A method for controlling an induction apparatus having an induction coil. In one implementation the induction apparatus includes a capacitor that is connected in parallel with the induction coil to form a parallel resonant circuit, and also includes a switch connected in series with the parallel resonant circuit, between the parallel resonant circuit and a reference voltage. According to one method, a digital test signal dependent on the voltage in a node disposed between the switch and the parallel resonant circuit is generated, the switch is closed for a predetermined closure time and then reopened at the end of the closure time. With the switch reopened, the test signal is evaluated for a predetermined waiting time in order to determine the presence or absence of a vessel on the induction coil.

Abstract: A system for determining the logic state of a resistive memory cell element, for example an MRAM resistive cell element. The system includes a controlled voltage supply, an electronic charge reservoir, a current source, and a pulse counter. The controlled voltage supply is connected to the resistive memory cell element to maintain a constant voltage across the resistive element. The charge reservoir is connected to the voltage supply to provide a current through the resistive element. The current source is connected to the charge reservoir to repeatedly supply a pulse of current to recharge the reservoir upon depletion of electronic charge from the reservoir, and the pulse counter provides a count of the number of pulses supplied by the current source over a predetermined time. The count represents a logic state of the memory cell element.

Abstract: A system and method for measuring resistance of a polarizing material are disclosed. The system includes a voltage divider circuit having a first resistive element of known resistance and the polarizing material of unknown resistance and a processing unit. The processing unit is electrically-coupled to the voltage divider circuit and adapted to apply a voltage across the voltage divider circuit. A first input/output (I/O) pin is electrically-coupled between the processing unit and the first resistive element. A second pin is electrically-coupled between the processing unit and a junction between the polarizing material and the first resistive element. A controller is adapted to cause the second pin to short the polarizing material after a measurement is completed, to bleed off any residual polarization from the capacitive element of the polarizing material.

Abstract: A method for measuring dielectric constant of body endermic tissues and body impedance based on the method of frequency digital sampling and for evaluating body composition is provided, inputting the method through the I/O interface of a microprocessor the measured body weight frequency signals, oscillating frequency signals related to dielectric constant of body endermic tissues and body impedance signals corresponding to non-fixed different frequencies, and calculating through the software of the microprocessor the body fat content, total body water, ratio between intracellular water and total body water. The body weight, body fat content, total body water and ratio between intracellular water and total body water are displayed on the display. A body composition monitor based on the above method, which includes a weighing sensor, a weighing signal processing circuit, and a display unit.

Abstract: A system for determining the logic state of a resistive memory cell element, for example an MRAM resistive cell element. The system includes a controlled voltage supply, an electronic charge reservoir, a current source, and a pulse counter. The controlled voltage supply is connected to the resistive memory cell element to maintain a constant voltage across the resistive element. The charge reservoir is connected to the voltage supply to provide a current through the resistive element. The current source is connected to the charge reservoir to repeatedly supply a pulse of current to recharge the reservoir upon depletion of electronic charge from the reservoir, and the pulse counter provides a count of the number of pulses supplied by the current source over a predetermined time. The count represents a logic state of the memory cell element.

Abstract: A device for measuring a resistance includes a comparator. A D-type flip-flop has its D input connected to the output of the comparator and its latch input connected for receiving a pulse signal at a fixed pulse repetition rate. A reference voltage source is connected to a first of the inputs of the comparator and an integrator is coupled between an output of the flip-flop and the second of the two inputs of the comparator. The integrator includes a resistor whereby the integrator develops a voltage at the second input of the comparator that depends on the pulse repetition rate and on the resistance of the resistor. The comparator, the integrator and the flip-flop are connected in a negative feedback loop such that at steady state the voltage developed by the integrator at the second input of the comparator is substantially equal to the reference voltage.

Abstract: A method and apparatus is provided for measuring alternating current (AC) and direct current (DC) characteristics of a plurality of semiconductor devices. A ring oscillator generates pulses to drive the plurality of semiconductor devices under test. Current/Voltage (IV) and transfer characteristics of the plurality of semiconductor devices are measured using only DC input/output.

Abstract: A digitizing ohmmeter system for providing a digital resistance measurement includes a current source for providing an excitation current to an impedance-varying input sensor and an ADC circuit including a charge-balancing modulator and a digital post processing circuit. The system utilizes synchronous AC excitation of the input sensor and an AC coupled analog-to-digital converter input. The digitizing ohmmeter system also implements correlated double sampling for noise cancellation to provide low noise and highly accurate analog-to-digital conversions. The ADC circuit includes a reference signal generator generating a resistance reference signal by time-sharing the excitation current with the input sensor. The digitizing ohmmeter system thereby realizes fully ratiometric operation such that neither a precise current source nor a precise voltage source is required for accurate resistance measurements.

Abstract: A digitizing ohmmeter system for providing a digital resistance measurement includes a current source for providing an excitation current to an impedance-varying input sensor and an ADC circuit including a charge-balancing modulator and a digital post processing circuit. The system utilizes synchronous AC excitation of the input sensor and an AC coupled analog-to-digital converter input. The digitizing ohmmeter system also implements correlated double sampling for noise cancellation to provide low noise and highly accurate analog-to-digital conversions. The ADC circuit includes a reference signal generator generating a resistance reference signal by time-sharing the excitation current with the input sensor. The digitizing ohmmeter system thereby realizes fully ratiometric operation such that neither a precise current source nor a precise voltage source is required for accurate resistance measurements.

Abstract: A sensor for converting a physical quantity into an electric signal and issuing the output is driven by a drive circuit which is driven by a drive signal issued from a 1-chip microcomputer. The 1-chip microcomputer judges fault of sensor function when the sensor output signal is out of a specified output range. Further, when stopping the operation of the drive circuit, if the sensor output signal does not coincide with a specific value, the 1-chip microcomputer also judges fault of sensor function. According to the invention, in the event of a trouble of sensor function allowing the sensor output signal to settle within an output range, such trouble can be detected.

Abstract: The system comprises at least one electronic sensor for detecting the presence of moisture. The system further comprises at least one reading device for obtaining information from the sensor about the presence of moisture. The sensor comprises a resonant circuit which is at least partly formed from a moisture sensitive material, the electrical resistance of which increases when the material comes into contact with moisture. The reading device comprises transmitter-receiver means for generating an elecromagnetic interrogation field.

Abstract: A self-adapting method for inhibiting corrosion of a component of a marine vessel performs a monitoring step during which a signal from the electrode is compared to a predetermined threshold magnitude. If the electrode is not connected to the circuit, the measured voltage will be approximately 0 volts. If the electrode is connected to the circuit, but in an inoperable condition, the voltage will also be lower than the threshold magnitude. In either of these situations, the present invention operates as an open loop control system. If, on the other hand, an appropriate signal is received from the electrode, the control system is operated in a closed loop manner. As a result, the circuit is able to adapt to the presence or absence of an operable electrode in the system.

Abstract: An electrical voltage arrangement to be provided with selectively different electrical input variables, for example in the form of a unidirectional voltage, a bidirectional voltage or a unidirectional current, can be converted into an impressed electrical output voltage. At the same time, there is to be a predefined relationship between the input variable and the output voltage. The circuit arrangement contains a first arithmetic circuit which converts a voltage fed to it into a first impressed voltage, and a second arithmetic circuit which converts an input voltage fed to it into a second impressed voltage. The voltage which is present at the input terminals of the circuit arrangenent is fed to the first arithmetic circuit. The voltage which drops across a resistor which can be connected to the input terminals of the circuit arrangement is fed to the second arithmetic circuit.

Abstract: An inter-chip line transmission circuit in a transmitting chip and complementary receiving circuit in a receiving chip provide the capability to characterize the inter-chip interface by separately generating identical pseudo-random test data at both chips, comparing the data, and recording errors. Preferably, one or both chips can be tuned on an individual line basis to reduce errors by altering threshold detection voltage, signal delay, and/or driver power. The receiver circuit preferably contains counters for counting test cycles and errors, which can be masked for any particular line or type of error. A tunable and characterizable interface in accordance with the preferred embodiment thus supports the accurate determination of low error rates on an individual line basis for various tuning parameter settings.

Abstract: A method of testing a high-side driver and a low-side driver in an airbag squib circuit includes preliminary testing of squib resistance and squib leakage for a plurality of trials. Next, one of the drivers is turned on while keeping the other one of the drivers off. A current-limited power supply supplies an intermediate voltage to a squib terminal and the voltage at the terminal is continuously compared with a predetermined voltage range which includes the intermediate voltage. The one driver is turned off in response to the voltage at the point being outside the predetermined voltage range, thereby detecting that the one driver is operating properly. If the voltage at the point remains in the predetermined voltage range for a predetermined time period, then the one driver is turned off and an indication is made that the one driver has failed. If the first driver passed, then the other driver is tested in the same manner.

Abstract: A method and device for detecting condensation on surfaces of structural components. A evaluation signal is generated before dewing while the structural component is cooling. A detectable film is produced on a measuring arrangement a few degrees Kelvin before the dew point is reached. The temperature is measured directly on the layer where the dew is developing.

Abstract: A monitoring circuit is provided to determine the proper operating condition of a cathodic protection circuit including a plurality of diodes and a capacitor. The monitoring circuit determines whether or not any of the diodes are shorted or open and whether or not the capacitor is open or operating properly. In addition, it determines whether or not the cathodic protection circuit is properly connected between a boat ground point and a shore ground point.

Abstract: A method and a device to assess the adequacy of a cathodically protected underground pipeline with consideration of AC corrosion. A steel probe and a CSE are installed near the pipeline at a depth. The steel probe is electrically connected to a pipeline. The measurements of AC probe currents flowing between a steel probe (2) and the pipeline (1) are per-formed simultaneously with those of on-and off-potentials, and DC probe currents.

Abstract: A sinusoidal voltage is appied to a zirconium alloy clad fuel rod. The current is measured and the impedance is determined to provide a check for the compactness and adhesion of an oxide surface layer on the fuel rod.

Abstract: Corrosion of a metal member under heat transfer condition is monitored by using a test coupon made of the same material as that of the metal member. The test coupon may have a welded portion and a crevice. One substantial surface of the test coupon is heated by a sheet shaped heating element, and at least one portion of the other surface of the test coupon is contacted with the corrosive fluid. After detecting a status of corrosion of the test coupon, the corrosion of the metal member is monitored based on the results of the detection. In case a counter electrode or reference electrode is used, the electrode is immersed in the corrosive fluid, and electrical signals between the test coupon and the electrode are measured. Then, the corrosion of the metal member is monitored.

Abstract: The present invention provides a device for measuring air quality. The device includes at least one sensor with a sensor resistance which is converted via signal processing into an output signal, the gas sensing or air content sensing device having its sensor(s) with electrical resistance that is a function of the air quality, such sensors being connected in an astable flipflop circuit arrangement with a first feedback resistor, a second feedback resistor, a capacitor and a comparator--where the first resistor is coupled between the inverting input and output of the comparator, and the second resistor is coupled between the noninverted input and the output of the comparator, and the sensor(s) is/are coupled between a reference potential and the noninverting input of the comparator. The output signal has a period which is related to the sensor resistance.

Abstract: A hand-held and flexible corrosion sensor is described that uses electrochemical impedance spectroscopy (EIS, also known as AC impedance) to detect coating degradation and corrosion of coated and uncoated metals. The hand-held and flexible corrosion sensor is pressed against the surface of the structure of specimen to be inspected, and may be either straight in structural configuration in the form of a pen or bent in a curved or angled manner to achieve better access to the structure. An EIS spectrum can than be obtained in the field or under arbitrary conditions and the degree of coating or material degradation can be determined from the resultant spectrum. There are no restrictions on the configuration of the structure being inspected. The area of detection is controlled by moderating the extent and degree of wetness of the surface. A dry surface will provide a localized measurement; a wet surface will allow inspection of the wetted area.

Abstract: It is an object of the present invention to provide a corrosion resistance test process, wherein the estimation of the corrosion resistance of an article formed of a metal material and a coating can be carried out synthetically and in a short time. In carrying out a corrosion resistance test, the article is immersed into an electrolytic solution and then, a voltage is applied to the metal material to carry out a metal material corroding step and a coating peeling-off step alternatively and repeatedly. The voltage applied to the metal material is a superimposed voltage Vd+Va resulting from superimposition of a DC voltage Vd and an AC voltage Va. A voltage condition of Vd<0 and Vd+Va>0 is established at the metal material corroding step, while a voltage condition of Vd<0 and Vd+Va<0 is established at the coating peeling-off step.

Abstract: A method and apparatus for detecting a loss in cross-sectional area of metallic reinforcing members having magnetic properties of a conductor indicating corrosion effects on the conductor. The method comprises providing a motive force to move a data collection component and a detector component along a length of conductor. The detector includes a rotating magnetic source spaced apart from an electronic coil winding. In use, a conductor is interpositioned between the magnetic source and electronic coil winding. The amount of magnetic field passing through the conductor induces a voltage in the coil inversely proportional to the cross-sectional area of the steel reinforcing strands of a conductor. The described apparatus can be used to determine the rate of loss of cross-sectional area for a conductor over a period of in use by measuring the cross-sectional areas of the metallic reinforcing members over an adequate time interval.

Abstract: A method for the early detection of electrochemical corrosion and coating degradation utilizing an inexpensive, in situ electrochemical metallic sensor for sensing coating and material degradation, particularly for materials such as aluminum 2024-T3, 7075, 6061, cold rolled steel samples, and coated metal structures such as automobiles, bridges, aircraft, and ships has been developed. The sensor utilizes AC Impedance or Electrochemical impedance spectroscopy (EIS) to acquire a precise, low-frequency impedance signature and is comprised of conductive ink deposited on a coating in the shape of the outline of a quadrilateral or other configuration. The resulting apparatus is comprised of a coated, metallic coupon used as a sensor, while a metallic grid electrode is deposited onto the steel coupon, thereby eliminating the need for a remote or counter electrode (i.e., reduction from a traditional, three-electrode system to a two-electrode system).

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 unique unitized measurement probe is temperature stabilized using thermally inertially balanced metallic probes; the first reference element being coated with an impermeable insulating coating, the second, the corroding element, being fully exposed to the corrosive fluid medium.

Abstract: A switching device including a measuring means for monitoring contact erosion, which is provided between a contact element and an associated contact support. The switching device includes an electrically insulated signal line, which is usable in individual and/or multiple contacts, is used as the measuring means, the signal line being integrated into a single monitoring circuit. In the switching device, there is arranged, between at least one of the contact elements and the associated contact support or in the contact material, an electrical conductor with insulator as the signal line, damage to or destruction of the insulator and/or the conductor being utilized to generate an external signal as an indication of the end of the service life of the contact element.

Abstract: A system for detecting faults in the insulation layer surrounding a concealed conducting pipe (10) includes a signal generator (12) for applying an alternating current with a frequency of around 4Hz to the pipe, a magnetometer (102) for detecting the alternating current from the pipe (10) and a CPU (115) for identifying changes in the gradient of the detected current along the length of the concealed conducting pipe (10) which are caused by the faults in the insulation layer. The magnetometer (102) is used in connection with a locator(100) which detects a second alternating current applied to the pipe (10) by the signal generator (12), this second alternating current having a frequency of around 128Hz. The system can also use both these signals to determine the direction of the signals emulating from the pipe (10).

Abstract: An electrode system for monitoring potentials between electrodes that includes a structure having a surface, a first electrode, a second electrode, an electrolyte, and a monitor to measure the potentials between the first and second electrodes. The first electrode is connected to the surface of the structure. The second electrode and surface of the structure are each in direct physical contact with the electrolyte so that a potential exists between the first and second electrodes. In certain embodiments, the electrode system may further include a reference electrode that is in physical contact with the electrolyte and physically isolated from the first and second electrodes so that a potential exists between the reference, first, and second electrodes. Optionally, the electrode system further includes an apparatus for measuring a background change in the potentials between electrodes and compensating for this background change.

Abstract: An apparatus and test method for determining the cleanliness (based on corrosivity) of a specific area on an electronic circuit assembly, such as the area between holes or pads on a single side of an assembly. The apparatus includes: (1) an extraction cell for providing an extraction fluid to an electronic circuit assembly ("ECA") area to be measured; (2) an extraction fluid for extracting residue from the ECA area to be measured; (3) a test cell with two or more electrodes and a voltage source for providing a voltage to the electrodes; and (4) a timer for measuring the time between the application of the voltage and an electrical short between the electrodes.

Abstract: Switching components with contact parts that are mounted on a contact carrier in a switch housing may include devices for monitoring the contact erosion. The contact carrier may be split (sub-divided) and contact parts can be slotted at the rear and mounted on the sub-divided contact carrier. Thus, the oscillation response (vibration response) of the contact carrier in particular can be used as a measure of the erosion of the contact parts.

Abstract: Measuring apparatus includes a first element having its impedance dependant on the state of its surroundings and a second element having a variable impedance connected to the first element. A voltage at the connection point between the first and second elements is converted into a digital value and the impedance of the second element is set based on the converted digital value. The surrounding state (e.g., humidity) is determined based on the converted digital value.

Abstract: In a process and a circuit arrangement for measuring the resistance of a resistance sensor, for instance a wetness sensor, via a rate of change of the charge of a capacitor, a measurement cycle consisting in each case of a charging of a capacitor, a discharging of the capacitor over the resistance sensor, and thereupon a measurement of the charge remaining in the capacitor, the direction of the discharge current through the resistor changes from measurement cycle to measurement cycle.

Abstract: A method and apparatus for determining the corrosivity of fluids on a metallic material by means of a coil with AC current with predetermined frequency, amplitude, wave form and range, and a metallic specimen with composition identical to the metallic material exposed to the fluid. The specimen, held within the magnetic field of the coil, sustains loss of mass by exposure to the fluid media with concomitant change in the magnetic quantities of inductivity and inductive resistance. Such changes are then converted from analog to digital, measured, collected and processed by a microprocessor.

Abstract: A magnetic field generator positioned externally of a non-ferrous metallic tructure being examined, is rotated at a relatively low speed to produce a rotating magnetic field penetrating the metallic structure to a selected depth as a function of spacing between magnetic poles of the generator parallel to a planar surface of the metallic structure. Traction between the metallic structure and the magnetic field accompanying its rotation is measured. Corrosion of the metallic structure at subsurface depths is detected and quantified from such traction measurements.

Abstract: This method and apparatus detects the potential for corrosion of pipes fabricated out of conductive material embedded in non-conductive material, due to contact between a conductive medium foreign to the pipe and the conductive material embedded within the pipe wall. The electric potential between the foreign medium and the pipe conductive material is determined. The stability of the potential is then ascertained. If the potential does not vary beyond a predetermined range over a period of time, the potential is deemed stable and is indicative of contact between the foreign medium and the conductive material within the pipe, fostering corrosion. An unstable voltage indicates lack of electrical contact.

Abstract: A corrosion degree measuring method capable of field measurement for intergranular corrosion, particularly the sensitization degree, of the plant's structural materials in a narrow space. The metal electrode made of a material being measured and the counter electrode to the metal electrode are immersed in an electrolytic solution. A voltage is applied to the metal electrode in the anodic direction so as to raise the potential of the metal electrode up to the passive state potential and to keep the metal electrode at the passive state potential. The passive state potential is used as a reference potential, and a pulse-like potential signal is applied to the metal electrode in the cathodic direction. At the time of the application of the pulse potential signal, a current between the metal electrode and the counter electrode is measured, and the corrosion degree of the material being measured is determined from the intensity of the current.

Abstract: An in situ probe failure detection method for probes which deliver an electric signal on account of a change of the concentration of a substance to be measured. An example of such a probe failure may be caused by, for example, fouling of the membrane as the relative change in signal may be interpreted as a change in the concentration of the substance to be measured. More particularly, the method involves detecting the need for calibrating probes, which probes deliver an electric signal on account of a change of the concentration of a substance to be measured, characterized by: (a) subjecting the probe to a stepwise change of the concentration of the substance to be measured; (b) calculating the value of the probe response time constant t.sub.c of the obtained measurement curve with the help of the following main equation (1): t.sub.c dy/dt=-y+.alpha..sub.0 +.alpha..sub.1 t wherein t=time (time), t.sub.c =probe response time constant (time), y=substrate probe signal (mass volume.sup.-1), .alpha..sub.

Abstract: A method for determining whether a metallic path (such as a wire) under test carrying an undetermined load current is so corroded as to require replacement applies a test current to the metallic path under test and a total current passing through the metallic path, equal to the sum of the undetermined load current and the test current, is measured. A voltage between two selected points, separated by a known length, on the metallic path is also measured. Resistance of the metallic path is then calculated by measuring an angular phase difference between the voltage and the total current, calculating an impedance of the metallic path from the values of the voltage and the total current then multiplying the impedance by the cosine of the angular phase difference. The resistance of the metallic path under test is correlated to the resistance of metallic paths of known corrosion to determine the degree of corrosion on the metallic path under test.

Abstract: An apparatus and a method are provided for determining solution resistance and corrosion rate of a metal surface contained in a solution such as an electrode. The signal is applied to the metal surface of interest and the current response is monitored from the applied signal. A peak detector is provided for detecting the peak of the current response. From the peak, the resistance of the solution is ascertained. Following independent determination of the solution resistance, polarization resistance of the metal surface in the solution may be determined. The corrosion rate of the metal surface may be calculated from the polarization resistance.

Abstract: The corrosion monitor system facilitates the detection and monitoring of material corrosion in remote areas. Sensors, which react to a corrosive environment similar to the material to be monitored, are placed in isolated areas and connected to a central control system via shielded cables. The system consists of a controller board, multiple dual preamp boards, a battery pack, sensors, and corresponding cables. The controller board consists of a microcontroller, memory, data conversion, and other control circuits. The dual preamp boards contain multiple precision instrumentation amplifiers, filtering, and voltage conversion circuits. The system operates on the principal that corrosion of a metallic conductor will cause a corresponding increase in the cross-sectional electrical resistance of that conductor. This change in resistance can be detected and monitored by passing a known constant current through the conductor and comparing the voltage across the conductor with that of a controlled reference conductor.

Abstract: A method for producing electrochemical impedance spectra. Spontaneously occuring coupling current noise between an array of electrodes which may be of substantially the same material is detected. A time domain record of the detected current noise is stored and the time domain record of the detected current noise is transformed to the frequency domain. Spontaneously occurring potential noise between the array of electrodes and a further electrode is detected. A time domain record of the detected potential noise is stored and the time domain record of the detected potential noise is transformed to the frequency domain. The frequency domain current noise and potential noise transformations are then transformed to the impedance domain to produce the required electrochemical impedance spectra.

Abstract: Electric bus bar insulating coatings are calibrated to withstand long term outdoor exposure without failure. Manufacturing samples of the coating material are evaluated at the coating manufacturing site prior to shipment to the bus bar manufacturer. Bus bar samples coated with the material are suspended within a heated water bath and subjected to several hundred volt-amperes. The thickness of the coating is predetermined to provide accurate qualifying data for each coating sample within a reasonable time frame. Coating compositions that qualify are then applied to electric bus bar conductors by the bus bar manufacturer.

Abstract: An eddy-current apparatus for measuring the conductivity of a conductive material and for reducing the influence of lift-off on conductivity measurements is provided. The apparatus includes a probe for inducing an eddy-current in a conductive material and a digital LCR meter for measuring the impedance of the probe when it is placed near the conductive material. A digital processor uses calibration impedance data obtained from a series of reference materials and an impedance measurement for a test material to produce a conductivity value independent of lift-off between the probe and the test material.

Abstract: The use of a sacrificial anode in a plumbing system or in the cooling system of an internal combustion engine or the like to protect the system against the destructive effects of electrolysis caused by the many different metals employed in modern plumbing systems or engines is disclosed, along with several methods and apparatus for monitoring the condition of the sacrificial anode to indicate when replacement is needed for continued protection of the system. Physical, optical and electrical systems are taught, each designed to indicate the need for replacement of the anode in an easily discernable manner.

Abstract: A simple, expedient method for measuring the effectiveness of a corrosion inhibitor provided to a metallic surface by a surface layer, wherein the layer is formed by use of the corrosion inhibitor is a corrosive fluid. The method employs the measuring of a high frequency phase angle as an indicator of inhibitor effectiveness.