Abstract: A method of cleaving a target nucleic acid molecule is disclosed. A cleavage structure is formed that comprises the target nucleic acid and a pilot nucleic acid. A first region of the target nucleic acid is annealed to the pilot nucleic acid to form a duplex structure. A second region of the target nucleic acid contiguous to the duplex is not annealed to the pilot nucleic acid, thus forming a junction site between the duplex region and the non-annealed region. The cleavage structure is exposed to a cleavage agent capable of preferentially cleaving the cleavage structure at a target site in a manner independent of the sequence of the cleavage structure. The cleavage structure and the cleavage agent are incubated under conditions wherein cleavage can occur.

Abstract: A target-specie responsive regulation of water treatment agent feed is achieved by the monitoring of a subject target-specie indicator. A target specie in a sample taken from the system is selected as the subject target-specie indicator, or instead an incipient reagent is added to the system sample to form a subject target-specie indicator. Such a formed subject target-specie indicator comprises a combination of the incipient reagent and a target specie. The subject target-specie indicator might then monitored by fluorescence analysis of the sample to determine at least one fluorescence emission value that can be correlated to the in-system concentration of the target specie. In combination with an inert tracer, the system consumption for the target specie can be determined. A responsive adjustment of the in-system concentration of a water treatment agent can be made.

Abstract: An atmospheric environmental monitoring method utilizes a corrosion test element prepared from a transparent substrate having two opposed surfaces. A corrodable film is applied to one surface of the substrate in the form of a thin wedge of metal and a security coating is applied to the opposite surface of the substrate. The surface of the corrodable film adjacent to the transparent substrate is reflective to radiation when viewed through the substrate. The security layer is designed to reflect radiation in at least the visible region of the spectrum and yet be transparent to radiation in other parts of the spectrum.

Abstract: Methods for determining the corrosivity of a substance to human skin or membrane are disclosed. In one approach, corrosivity is evaluated by measuring the time required for the test substance to transit a biobarrier that mimics human skin or membranes or the time required to cause a component of such biobarrier to break down and transit the membrane. The invention also envisions alternative approaches which involve series of layers of dyes and corrosive-resistant materials coated onto microspheres or test strips. Use of these methods provides a rapid determination of the corrosivity of test materials.

Abstract: A method and apparatus is provided for the simultaneous measurement of the general corrosion rate and the atomic hydrogen permeation rate through at least two like specimens in the same test cell, under the same conditions at the same time.The nonconductive electrochemical test cell is adapted to receive at least two test specimens and associated electrodes and electronic and physical measuring means. One or more chemical additives can be introduced into the cell to determine their effect on inhibiting hydrogen permeation and corrosion rates as reflected by the respective measurements. This procedure can be repeated for other inhibitors, and, from the data obtained, a comparative ranking of the effectiveness of inhibitors can be assigned.

Abstract: An electrode for determining corrosion of metal reinforcement in concrete includes a wire surrounded by insulation and made of a metal which is more electro-positive than a metal reinforcement. An electrically active part of the wire is in electrolytic contact with moisture in concrete surrounding the reinforcement. The insulation is disposed along the whole of the electrically active part of the wire in such a way that the insulation keeps this part of the wire separated from the reinforcement and galvanically insulated therefrom.

Abstract: A method for testing engine lubricating oil under simulated engine operating conditions including a tank with an interior space containing a quantity of engine lubricating oil, an elongated tubular enclosure for passing oil from one end to the other, and an oil pump to cause oil to flow from the tank through the tubular enclosure. The tank includes devices to introduce oil oxidizing agents to the oil. A metal rod extends centrally through the enclosure so that oil passes along its outer surface and the rod is selectively heated so that oxidation deposits form along the rod. Examination and analysis of the rod and its deposits permit rating of a particular oil for its oxidation resistant properties.

Abstract: Concentration of a polyelectrolyte in the water of an aqueous system is controlled by first withdrawing a sample of the water and adding a known or standard amount of a fluorochromatic reagent to the sample. Then light energy is directed into the sample whereby light energy of a selected excitation wavelength for the fluorochromatic dye is available for absorption by the fluorochromatic reagent. The intensity of light emitted about a selected emission wavelength for the fluorochromatic reagent is measured and the intensity of the emitted light is compared to a standard curve, comprising a plot of fluorescence emission intensity of the fluorochromatic reagent in the presence of a polyelectrolyte versus concentration the polyelectrolyte. The concentration of the polyelectrolyte in the sample of water is determined from the comparison.

Abstract: An apparatus and process for simulation of field fluid flow conditions under elevated temperature and pressure conditions of oil and gas production, refining, cooling towers, desalinization. The process involves evaluating inhibitor action in reduction of a specified chemical reaction under simulated field aqueous flow conditions by forming first and second aqueous flow streams having a preset concentration of anions and cations, respectively, for the specified chemical reaction with at least one of these streams having a concentration of the inhibitor to inhibit the specified chemical reaction. These streams are combined to form a single process stream where the specified chemical reaction may take place. The process is repeated with successive reductions in inhibitor until detecting the specified chemical reaction in the process stream.

Abstract: A method and system for monitoring the presence of a corrosive constituent in a petroleum product. [The invention detects the reflected] Reflected radiation is detected from a metal standard in the petroleum product which indicates the presence of the corrosivity constituent.

Abstract: A corrosive environmental crack length measuring apparatus including a double-cantilever beam type test piece having a tapered portion in a portion where the crack grows, a slit, and at least two holes, with the test piece being placed within a corrosive environment. Leads inserted in the holes of the test piece to be spot-welded thereto to supply a direct current to the holes. A current polarity switching device is provided with, a stabilized direct current power supply connected with the direct current supplying leads through the current polarity switching device. Potential difference measuring leads are inserted in holes formed in two outer faces of the double-cantilever beam type test piece parallel to a section of a crack growing portion at a plurality of points along the crack growing direction so as to be spot-welded thereto.

Abstract: A crack propagation test specimen has a base metal and a clad metal. The base metal has an upper surface and a bottom surface with a hole extending from the bottom surface toward the upper surface. The cladding metal is supported on the upper surface of the base metal and has a first slot cut therethrough which is in fluid flow communication with the hole in the base metal. A second slot is cut in the cladding metal adjacent to the first slot for receiving a wedge. The first slot and the second slot define a wall which closes over the first slot when a wedge is forced into the second slot to simulate a hairline crack. A mechanically deformed metal sample is disposed in the hole in the base metal to simulate a stressed base metal supporting a cladding metal subject to hairline cracking.

Abstract: An apparatus for testing engine lubricating oil under simulated engine operating conditions including a tank with an interior space containing a quantity of engine lubricating oil, an elongated tubular enclosure for passing oil from one end to the other, and an oil pump to cause oil to flow from the tank through the tubular enclosure. The tank includes devices to introduce oil oxidizing agents to the oil. A metal rod extends centrally through the enclosure so that oil passes along its outer surface and the rod is selectively heated so that oxidation deposits form along the rod. Examination and analysis of the rod and its deposits permit rating of a particular oil for its oxidation resistant properties.

Abstract: Method and apparatus are provided for testing parts and materials in a controlled environment, especially an atomic oxygen environment. The apparatus includes a housing which has sample station located in its interior to receive a test sample. A contact element contacts a surface of the test sample, and a drive reciprocates the contact element so that the surface is subjected to wear along a wear path. At least one testing fluid is introduced and removed from the interior with the locations of introduction on removal preferably being such that the testing fluid flows across the test sample. The drive may be a carriage operated through the housing sidewall by a ferromagnetic coupling, and the sample station may be a turntable rotated by a ferromagnetic coupling. A second sample station may be included so that different wear path configurations are possible.

Abstract: A bench-test method which correlates well with other more costly engine test methods, and which can be used to screen oleaginous formulation prior to performing expensive engine tests. The method comprises a) contacting ball bearing(s) having a smooth surface area with an oleaginous fluid to be screened; b) treating the oleaginous fluid during contacting with corrosive vapor for a period of time and at a temperature sufficient to form a metal oxide coating on the ball bearing(s) surface; and c) visually rating the metal oxide coating on the ball bearings.

Abstract: A test specimen for evaluating crack propagation and associated wear and corrosion on cladded piping is provided. The test specimen simulates the hairline crack conditions found on the inner cladding layer of a piping system. The test specimen is useful in analyzing the effects that a certain process fluid has on an exposed cracked cladding layer surface.

Abstract: An improved short-term autoclave (10) test for ex-reactor evaluation of in-reactor corrosion resistance of zirconium alloy members (16) for use in pressurized water reactors and pressurized heavy water reactors by:providing a heat flux to initiate hydride precipitation close to the metal-oxide interface of the tube outside surface by means of a resistance heater (20) and a directed flow of aqueous coolant in the water phase to only the outside surface which is one of two specimen (16) opposed surfaces; providing the inside surface with access to the coolant from the flow but not in the flow; reducing the distance between the opposed surfaces of specimen (16);regulating coolant flow from inlet port (12) to outlet port (14) and power of autoclave (10) to optimum saturation condition of 360.degree. C..+-. 5.degree. C. and pressure 2700 p.s.i..+-. 100 p.s.i.;providing a coolant chemistry which simulates a rector's;removing most of the oxygen from the coolant.

Abstract: The installation comprises a selective liquid-feeder assembly, a selective gas-feeder assembly for feeding gas under pressure, a mixing and preheating assembly itself comprising a vaporizing stage, a mixing stage, and a preheating stage to raise the gas-vapor mixture to a temperature of about 150.degree. C. to about 300.degree. C., and a distributor assembly for distributing the flow of gas-vapor mixture to a plurality of high temperature generalized corrosion test circuits. Each test circuit comprises a reactor including an intermediate preheater stage for preheating the gas-vapor mixture applied to the reactor to a temperature of about 400.degree. C. to about 600.degree. C., and a final heater stage containing at least one sample of material to be tested which sample is put into contact with the gas-vapor mixture flow from the intermediate preheater stage, and raised in the final heater stage to a temperature lying between about 700.degree. C. and about 850.degree. C.

Abstract: A method for determining the presence of ferrous ion in boiler waters is described. The method can be used to directly measure the rate of corrosion occurring in boiler waters, and can measure the corrosion rates in the presence of boiler water treatment chemicals. The method uses a complex formed between only ferrous ion and a chemical 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine-p,p'-disulfonic acid monohydrate reagent.

Abstract: A method and apparatus for using a coated piezoelectric crystal to monitor and report corrosion in terms recognized as conforming to an industry standard is disclosed. The present invention provides a method of and system for monitoring corrosion in a corrosive atmosphere, comprising and carrying out the steps of exciting in the atmosphere a crystal, coated with a corrodible metallic substance and having a known vibration frequency; measuring the change in the frequency of vibration resulting from corrosion of the corrodible substance during each of a plurality of intervals of time, including a reference interval and at least one subsequent measurement interval; generating a thickness signal representing the thickness of corrosion corresponding to the measured change in frequency during the measurement interval; and converting the corrosion thickness signal for the measurement interval to a reference signal representing the thickness of corrosion accumulated during the reference interval.

Abstract: An apparatus and method for monitoring corrosion to members within the core of a nuclear reactor, particularly fuel rod cladding. A sensor means is submerged inside the core of a nuclear reactor near the member or fuel rods. The sensor means is comprised of a generally cylindrical section having an outer surface that is subject to corrosion and radiation, and has a cross-sectional area A.sub.1. The sensor means additionally has a reference section subjected to radiation but not to corrosion, and having a cross-sectional area A.sub.2. At least one pair of first probes, separated by a length L.sub.1, is placed in electrical contact with the cylindrical section. At least one pair of second probes separated by a length L.sub.2, is placed in electrical contact with the reference section. A current is passed throughout the sensor means to produce a potential gradient in the cylindrical section and reference section.

Abstract: Generally, the invention provides a fouling probe apparatus. The fouling probe including a heat transfer conduit having a first portion formed as a loop which is removably attached to a second portion which extends linearly. A hollow housing encases the apparatus. The housing has an open forward portion and an open rear portion. The open forward portion is attachable to an oil quench tower about an opening in the quench tower and the open rear portion is adapted to be securely attached to the linearly extending second portion of the heat transfer conduit. A fouling grid is attached to the first portion of the heat transfer conduit. The fouling grid is super-heated to accelerate fouling.

Abstract: A test specimen for evaluating crack propagation and associated wear and corrosion on cladded piping is provided. The test specimen simulates the hairline crack conditions found on the inner cladding layer of a piping system. The test specimen is useful in analyzing the effects that a certain process fluid has on an exposed cracked cladding layer surface.

Abstract: A probe retraction tool including a threaded split shaft connected to a packing gland in coaxial relation to a probe inserted therein. The shaft has a longitudinally coextensive slot and axial bore within which the longitudinal axis of the shaft extends in parallel relation thereto. A spinner nut is threadably connected to the shaft and has a slip ring concentrically mounted thereon for relative rotational movement. A member for securing the probe to the spinner nut is connected to the slip ring and extends within the channel to detachably connect with an upper end of the probe. A handle is connected to the spinner nut for rotating the same, thereby urging the spinner nut, the slip ring and the probe in coaxial vertical movement along the longitudinal axis of the split shaft.

Abstract: A process is described for direct determination of complex corrosive environmental conditions, which comprises exposing a glass surface to the environment and examing the glass surface before and after exposure using a measurement method based on radiation, in particular a IR-spectroscopic method, in order to determine corrosion effects, in particular water absorption and ion exchange. Glass sensors suitable for use in this process are likewise described.

Abstract: There is disclosed a portable apparatus and process for using same including a test conduit assembly and related conduit valve and fluid flow assemblies for conecting to a process unit for fluid flow communication with the test conduit assembly for passing a fluid to be evaluated for corrosive effect on such test conduit assembly wherein the test conduit assembly includes a test conduit of a predetermined length disposed in a transparent conduit section for passing the fluid therethrough and wherein a heating unit of a predetermined length is disposed in the test conduit wherein the heating unit is of a length of at least about 2 inches and comprises less than about 50 percent of the predetermined length of the test conduit.

Abstract: Repetitive DNA sequences of the protozoan parasites T. cruzi and P. falciparum have been isolated. These sequences appear more than once in the parasitic organism. Once isolated, the DNA sequences may be labelled with materials such as chromogens, biotin, or radioactive substances. The sequences may be used, in labelled or unlabelled form, as probes for the parasites.

Abstract: The present invention is a method of determining oxidation on a titanium aluminide material. An aqueous saturated solution of oxalic acid is prepared. The saturated solution of oxalic acid is combined with a minor portion of hydrofluoric acid solution. The resultant oxalic acid/hydrofluoric acid solution is mixed. The titanium aluminide material is immersed in the mixed solution for a sufficiently long period to allow exposure of the oxidized surface followed by inspection thereof for a white layer indicating the presence of oxidation on its surface.

Abstract: Both an improved method and apparatus for determining, on an accelerated basis, the susceptibility of a nickel-based alloy to suffer stress corrosion cracking within a steam generator environment is disclosed herein. The method generally comprises the steps of subjecting a mechanically stressed specimen of the alloy to a mixture of steam and hydrogen at a temperature of between about 365.degree. C. to 435.degree. C., wherein the partial steam pressure is between about 10.4 MPa to 30.4 MPa, and the partial hydrogen pressure is between about 32 kPa to 500 kPa. The improved testing apparatus of the invention generally comprises a vessel for containing a stressed specimen and a pressurized atmosphere formed of steam and hydrogen, and an inlet cell for injecting a selected amount of hydrogen into the pressurized atmosphere of the vessel which includes a diffusion membrane which is permeable to hydrogen but impermeable to the remainder of the pressurized atmosphere.

Abstract: A corrosion product monitoring system and method are described using a recirculation loop including a sample line, a particulate collection vessel, a recirculating pump, a microporous membrane "cross-flow" filter, and valves to control the flow rate and pressure of a fluid sample taken from the secondary fluid system of a nuclear power plant. The liquid sample is processed at a constant flow rate and temperature. When a relatively short time has elapsed in a trial sample run to stabilize conditions in the sample line, an actual sample run is started by feeding sample into the loop. Non-soluble, particulate concentration increases in the filter and particulate collection vessel as the run progresses. The permeate of soluble contaminants is passed through an ion exchange column to concentrate soluble ions in the sample. The filter is backwashed on a timed cycle by filtered water pressurized by a pump, or gas pressure, by realigning the system valves.

Abstract: An out-of-reactor method for screening to predict relative in-reactor hydriding behavior of zirconium-bsed materials is disclosed. Samples of zirconium-based materials having different composition and/or fabrication are autoclaved in a relatively concentrated (0.3 to 1.0M) aqueous lithium hydroxide solution at constant temperatures within the water reactor coolant temperature range (280.degree. to 316.degree. C.). Samples tested by this out-of-reactor procedure, when compared on the basis of the ratio of hydrogen weight gain to oxide weight gain, accurately predict the relative rate of hyriding for the same materials when subject to in-reactor (irradiated) corrision.

Abstract: The apparatus comprises a stack of corrosible members retained in position by a support, and measurement means, for example a dial gauge, arranged to measure any change in the height of the stack when exposed to a corrosive environment. Electrical potentials and/or mechanical stress can be applied to the stack in order to ascertian the influence thereof on corrosion. The use of a plurality of corrodible surfaces enables amplification of dimensional changes and enables measurements to be obtained in a relatively short time.

Abstract: The present invention is a method of rapidly and reproducibly checking the quality of zirconium base material welds and heat affected zones. In this method, weldment samples are immersed in an elevated temperature fused salt bath for a time period sufficient, at the bath temperature selected, to produce an essentially black oxide film in acceptable quality welds while producing a scaling oxide in unacceptable welds.

Abstract: A corrosion cracking test assembly comprising a pair of strips each having notches formed along one edge and assembled in a stressed condition.

Abstract: Coated carbon composite parts to be tested for oxidation resistance are heated in a closed oven filled with an oxidizing atmosphere. During the heat cycle the carbon dioxide content of the oven atmosphere is measured by an analyzer such as a gas chromatograph. These measurements on the amount of CO.sub.2 emitted by the part provide information on the onset of oxidative failure. It forms a nondestructive test when detection of excessive carbon dioxide concentration is used to reduce the temperature and flood the oven with inert gas so the part may be saved and reprocessed. This technique can be combined with conventional weight measurements before and after oxidation to identify the part constituent, carbon composite or protective coating, that failed.

Abstract: According to the invention a piezoelectric crystal, e.g. a quartz crystal, coated with a metal or another suitable material is exposed to the action of a corrosive liquid, preferably by being immersed therein. The mass change on the crystal surface, caused by the corrosion, and the resulting change in the natural oscillation frequency of the crystal is determined and constitutes a measure of the corrosivity of the liquid. The natural oscillation frequency of the crystal can in this way also be measured in situ in the liquid, in which way the dynamic course of the corrosion reaction can be followed continuously. According to a special embodiment of the invention the sensitivity during the measurement can be increased, if the crystal is pretreated by being activated with a sulphide solution.

Abstract: A method of detecting the rate of corrosion of an existing steel structure installed in a corrosive environment is disclosed. The method includes treating a measurement surface of the member so that an AC impedance of the measurement surface, when electrochemically measured at a predetermined high frequency range of potential variation applied to the measured surface, takes a first valve within a predetermined range; and second value of the impedance is then electrochemically measured at a low frequency range of potential variation applied thereto. The difference between the first and second values is calculated to detect the corrosion-reaction resistance of the surface and the rate of corrosion is determined on the basis of the detected corrosion-reaction resistance and according to a pre-calculated relation between the rate of corrosion and the corrosion-reaction resistance.

Abstract: The invention comprises a method for determining the corrosion rate of metals in contact with a liquid system which is capable of causing corrosion of such metals which comprises adding to the liquid system an electrochemically active compound having a reduction potential more positive than the metal in contact with the liquid system and then monitoring the system thus treated with the electrochemically active compound to determine its rate of reduction which is proportional to the corrosion rate of the metal.

Abstract: A diffusing apparatus is adapted for vertically adjustable relation with a fog tower. A separate second corrosive fluid is emitted from plural outlets spaced approximately 45.degree. apart along the exterior of the diffusing apparatus. The outlets direct the second corrosive fluid in a generally planar direction substantially perpendicular to the longitudinal axis of the fog tower for optimum uniform dispersion either alone or intermixing with a first corrosive fluid emitted from the fog tower.

Abstract: A model steam generator including an improved feedwater system for monitoring the conditions of the heat exchange tubes within a nuclear steam generator is disclosed herein. The feedwater system generally comprises a first conduit fluidly connected between the boiler vessel of the model steam generator and the feedwater of the nuclear steam generator via a first valve, and a second conduit which is fluidly connected between this boiler vessel and a feedwater reservoir by way of a second valve. The feedwater reservoir is in turn connected to a source of demineralized, deaerated water by means of a third conduit having a third valve. This reservoir is further fluidly connected to the feedwater of the nuclear steam generator by means of a fourth conduit having a fourth valve. The improved feedwater system of the invention gives the operator three running options. First, he may run the model steam generator directly off the feedwater used in the nuclear steam generator.

Abstract: A corrosion coupon holder for inserting and removing a coupon from the interior of a pipeline while under pressure has an elongated housing with a threaded connection at one end and a removable closure device at the other end, the housing connection to be attached to a pipe entry valve which is connected as a branch to the pipeline. The housing other end also carries a guide body having a bore which guidingly and sealingly receives a rod for inserting a coupon having a safety stop element at one end to hold the coupon, the guide body having a split collet associated with the bore with a locking screw mounted to act on the collet to fixedly clamp the rod in the bore of the guide body and the housing having a bleeder valve communicating with the interior to relieve pressure from within such interior.

Abstract: A corrosion coupon anchoring system for positively positioning a corrosion monitoring coupon in the production flowpath downhole in a producing well. Preferably cylindrical coupons are held firmly within a cylindrical housing suspended out of contact with any other metallic surface. An adaptor threadingly engages the cylindrical housing to a conventional locking mandrel that is locked in place to a nipple positioned in the tubing string. The minimum internal dimension of the coupon holding section is not less than the minimum internal dimension of the locking mandrel so as to minimize flow restriction introduced by the anchoring system.

Abstract: The invention comprises a method for determining the corrosion rate of metals in contact with a liquid system which is capable of causing corrosion of such metals which comprises adding to the liquid system an electrochemically active compound having a reduction potential more positive than the metal in contact with the liquid system and then monitoring the system thus treated with the electrochemically active compound to determine its rate of reduction which is proportional to the corrosion rate of the metal.

Abstract: A sensor apparatus cooperates with an electrical system capable of delivering power to and receiving signals from the sensor. A cable housing insulated wires is connected to the sensor and disposed in proximity to a fluid possibly containing a corrosive impurity. Corrosion detecting elements are connected to the wires and are immersed in the fluid possibly containing the impurity. Further, the elements are provided with breakable regions fabricated to corrode in the presence of the corrosive impurity. To facilitate fracture, the elements are loaded in tension so the breakable regions will fracture rapidly in the presence of corrosive impurities, to thereby send an electric signal to remote electrical equipment to indicate the presence of at least one impurity.

Abstract: Techniques and apparatus are described for measurement of corrosion of drill pipe in a well bore during drilling. The techniques involve the use of a test coupon attached to the external surface of a drill string. In a preferred embodiment the test coupon comprises a metal plate mounted in an insulating material such as plastic. The test coupon is preferably secured within a recess in the external surface of a sub connected between segments of a drill string.

Abstract: A method is described for testing equipment to determine whether it will continue to function when in the presence of a sodium fire, which is of much less cost than prior testing methods. The method includes spraying sodium monoxide on the equipment while it lies within an enclosure. The sodium monoxide is a fine powder, and the moisture within the chamber is maintained at a high level which is much above 20%. The moisture turns the sodium monoxide to sodium hydroxide, or lye, which is the most damaging component of a sodium fire.

Abstract: Apparatus for determining the corrosion rate of industrial condensing equipment so that corrosion inhibitors may be effectively utilized to control corrosion. The apparatus which simulates a cooling circuit for process streams which require the introduction of reagents to inhibit corrosion includes a primary condenser with automatic cooling control and more than one serially connected cooling-monitoring section, associated means for monitoring corrosion rate, temperature, and/or dewpoint and means for adjustibly controlling the process stream cooling rate of said cooling-monitoring sections. The process stream is flowed through said serial connected cooling-monitoring sections in order to cool the vapors in a manner which simulates cooling that will take place in a parallel connected heat exchanger unit.

Abstract: A corrosion test assembly adapted for operative placement in a flowing gaseous medium for subjection to corrosive materials therein, more particularly, in scrubber systems, the assembly including a support and mounting means removably attachable to an outer surface of a component containing a flowing gaseous medium wherein at least one corrosion test specimen or coupon is mounted on the support and mounting means, with the test member extendable into the gaseous medium, wherein the test specimen is subjected to corrosive action by corrosive materials in the gaseous medium.

Abstract: A sample of material which is to be exposed to a hot gas corrosion is suspended in a pipe and is irradiated with heat radiation through parabolic mirrors through the pipe. Beneath the sample of material, there is found a thermocouple element which is also arranged along the focusing line. The substance stimulating corrosion is provided in a crucible furnace which is heated separately. Through a gas connection, gas or steam is supplied in order to generate the atmosphere stimulating corrosion in the pipe. The variations in weight of the sample of material are continuously measured with a balance.

Abstract: A method and apparatus herein is disclosed that consists of establishing and equilibrating a circuit path through a working test pipe electrode and a counter electrode in an electrolyte fluid in which said test pipe electrode achieves a state of cathodic protection. Disconnecting said cathodically protected working test pipe electrode from said counter electrode. Then re-establishing a circuit path through said working test pipe electrode, said counter electrode, and a reference electrode, in said electrolyte fluid along with an electronic control and measuring means. Subsequently causing a measured known voltage step to be applied to said working test pipe electrode. Then measuring the current flowing after application of said measured applied voltage step. Finally, then analyzing said current flow data and thereby determining the double layer capacitance at the interface between said working test pipe electrode and said electrolyte fluid as a measure of disbonded area thereon.