Abstract: A method of testing a treating iron component for the presence of a defect in structural integrity is presented. The treating iron component is subjected to test conditions of hydrostatic pressure. Test acoustic emission from the treating iron component while under the test conditions can be detected by at least one acoustic sensor and compared to standard acoustic emission detected by subjecting a similar non-defective treating iron component to the same test conditions of hydrostatic pressure. An increase in the test acoustic emission compared to the standard acoustic emission indicates the presence of a defect in the structural integrity of the treating iron component.

Abstract: Pulverizer coal flow pipes feed a mixture of air and coal to burners in electric utility coal fire facilities. A method and apparatus for sensing relative coal flow in the pipes uses acoustic emission (AE) sensors to detect flow in each pipe. Sensed relative flow in the pipes is used to balance flow in the pipes and to further adjust pipe coal flow. Sensed flow is used with control parameters of a furnace to maximize power plant efficiency and to ensure compliance with emissions requirements.

Abstract: A method for detecting loss of SF6 gas from electrical utility apparatus determines a molar ratio of gas in a container at an initial time and of gas in the container at a subsequent time. Measurement of temperature is determined by averaging ambient temperature and temperature of the surface of the container. The initial values of pressure and temperature define the initial value of n as follows: no=Pgas o/Tgas o The value at a subsequent time is nn=Pgas n/Tgas n The molar ratio can be defined as nn/no or as no/nn.

Abstract: An inductive bridge circuit using mutual inductances to transform impedances is used for detection of wall-thinning defects in metals. The bridge circuit has a first test coil placed adjacent to a good metal section and a second test coil placed adjacent to a metal to be tested. The bridge circuit compares the inductance in the first coil and inductance in the second test coil to compare wall thinning defects. The apparatus may also include first and second measuring transformers which are connected between the bridge circuit and the test coils where the transformers provide for impedance matching and reduced current requirements in the bridge. The circuit may also include one or more potentiometer circuits connected across the bridge which are used for compensating for imbalance of impedance between the first and second test coils when the coils both have known good metal sections adjacent to them.

Abstract: An inductive bridge circuit using mutual inductances to transform impedances is used for detection of wall-thinning defects in metals. The bridge circuit has a first test coil placed adjacent to a good metal section and a second test coil placed adjacent to a metal to be tested. The bridge circuit compares the inductance in the first coil and inductance in the second test coil to compare wall thinning defects. The apparatus may also include first and second measuring transformers which are connected between the bridge circuit and the test coils where the transformers provide for impedance matching and reduced current requirements in the bridge. The circuit may also include one or more potentiometer circuits connected across the bridge which are used for compensating for imbalance of impedance between the first and second test coils when the coils both have known good metal sections adjacent to them.

Abstract: Relevant resonance response characteristics of a sample are determined for use in characterizing the sample for non-destructive testing. The sample is excited by an exciting mechanical input at a plurality of ultrasonic frequencies. The response is separated into in-phase and quadrature components and the resonance response characteristics are computed from the in-phase and quadrature components. Apparatus for obtaining the relevant response characteristics includes a frequency generator for inputting an exciting ultrasonic frequency to the sample. A transducer outputs a response of the sample to the exciting ultrasonic frequency. A dynamic signal analyzer is connected to receive the response of the sample and to output in-phase and quadrature components of the response of the sample. A computer then determines the relevant response characteristics from the in-phase and quadrature components.

Abstract: A method of measurement of objects by resonant ultra sound is used to determine object surface to near surface flaws. First, the frequency for expected degenerate surface acoustic wave responses is determined for one or more input frequencies and then splitting of degenerate resonant modes are observed to identify the presence of surface flaws in the object.

Abstract: A method of measurement of objects to determine object flaws, Poisson's ratio (.sigma.) and shear modulus (.mu.) is shown and described. First, the frequency for expected degenerate responses is determined for one or more input frequencies and then splitting of degenerate resonant modes are observed to identify the presence of flaws in the object. Poisson's ratio and the shear modulus can be determined by identification of resonances dependent only on the shear modulus, and then using that shear modulus to find Poisson's ratio using other modes dependent on both the shear modulus and Poisson's ratio.

Abstract: An ultrasonic measurement method for distinguishing between unflawed and flawed parts comprises the steps of detecting at least two prominent resonant response frequencies, measuring the frequency difference between the two frequencies, determining the ratio of the frequency difference to one of said frequencies, and comparing the ratio to a predetermined part criterion. Resonant response frequencies dependant upon physical characteristics such as dimensions and weight are compared to other resonances which are at frequencies dependant upon stiffness of the part.

Abstract: A method and apparatus for ultrasonic resonance testing of an object is shown and described. Acoustic vibrations are applied to an object at a plurality of frequencies. Measurements of the object's vibrational response are made simultaneously at different locations on said object. The input frequency is stepped by using small frequency changes over a predetermined range. There is a pause interval or ring delay which permits the object to reach a steady state resonance before a measurement is taken.

Abstract: Method and apparatus are provided for detecting crack-like flaws in components. A plurality of exciting frequencies are generated and applied to a component in a dry condition to obtain a first ultrasonic spectrum of the component. The component is then wet with a selected liquid to penetrate any crack-like flaws in the component. The plurality of exciting frequencies are again applied to the component and a second ultrasonic spectrum of the component is obtained. The wet and dry ultrasonic spectra are then analyzed to determine the second harmonic components in each of the ultrasonic resonance spectra and the second harmonic components are compared to ascertain the presence of crack-like flaws in the component.

Abstract: A process for drying a conductive material, particularly coal, by subjecting the material to microwave energy is disclosed. A conductive aggregate is directed through a region where microwave energy excites absorbed water molecules and the conductive material causing the water to evaporate, leaving behind a drier material.