Abstract: An improved induction tool for formation resistivity evaluations. The tool provides electromagnetic transmitters and sensors suitable for transmitting and receiving magnetic fields in radial directions that are orthogonal to the tool's longitudinal axis with minimal susceptibility to errors associated with parasitic eddy currents induced in the metal components surrounding the transmitter and receiver coils. The present invention provides increased effective tool surface impedance by increasing self-inductance of the paths in which induced eddy currents flow on the surface of the multi-component induction instruments.

Abstract: An apparatus for measuring the resistivity of earth formations penetrated by a wellbore having a conductive conduit. The apparatus includes an elongated sonde mandrel, a plurality of electrodes positioned at axially spaced apart locations along the mandrel, the electrodes being electrically insulated from the mandrel and from each other, the electrodes adapted to electrically contact the conduit and positioned collinearly so that the electrodes contact the conduit when the mandrel is radially displaced towards the wall of the conduit. Some electrodes are for injecting electrical current into the conduit, other electrodes are for measuring voltage drop along the conduit at axially spaced apart locations. The mandrel includes selectively extensible locking arms for urging the mandrel into contact with the conduit. The arms are radially positioned opposite to the electrodes.

Abstract: A system for monitoring and controlling the color and shade in a decolorization or fading process for textiles. The system contains a visible light source which illuminates a sample of a dyed textile. A scanner reads the illuminated sample and provides an optical image which is sensed by optical transducers which transforms it into an representative electronic signal which is analyzed for a chroma signal component (image color content) and/or luminance component (image shade/gray scale content). A process control computer monitors and adjusts the process speed and at predetermined color and shade finish stops the decolorization process based on the measured and processed image contents which is tracked by a calibrated and sensed optical image represented by processed electronic signals.