Abstract: A method and apparatus for detecting and removing water from a surface of a moving metal sheet in continuous treatment line to prevent the formation of water stains thereon. A selected surface area of the moving metal sheet is illuminated with infrared radiation having a wavelength substantially absorbed by water, and an optical sensor system is employed to view images reflected off the selected surface area. An optical bandpass filter limits transmission of infrared light to within a specific range of wavelengths known to be strongly absorbed by water. The sensor assembly produces a signal representative of the intensity of the reflected light. If the intensity signal is lower than a predetermined level, water is detected and the signal may be used to trigger a control device that sounds alarms, records the event, or otherwise controls the environment of the object so that detected water may be removed to prevent the formation of water stains.

Abstract: A method and apparatus for detecting the presence of water on a surface of an object using infrared radiation. A surface area to be detected is illuminated with infrared radiation having a wavelength substantially absorbed by water. An optical system is employed to view images reflected from the surface area. An optical bandpass filter is disposed between the surface area and the sensor to limit transmission of infrared light to within a specific range of wavelengths known to be strongly absorbed by water. The sensor assembly produces a signal representative of the intensity of the reflected light. If the intensity signal is lower than a predetermined level water is detected and the signal may be used to trigger alarms, record the event or otherwise control the environment of the object. The present invention is particularly suited for detecting the presence of water on a moving sheet of metal during a manufacturing process.

Abstract: Method and apparatus for measuring the surface temperature/emissivity of coated steel strip during a coating (e.g., galvannealing) process. The apparatus includes first and second radiation sensors each having a response exponentially related to the reciprocal of absolute temperature when viewing a blackbody source, and each positioned to receive focused radiation from the surface to be measured to provide first and second signals indicative of the radiation received by the sensor, respectively. To provide the focused radiation, the apparatus includes an optical system for gathering thermal radiation emitted by the surface to be measured and focusing it onto the sensors after a first common filter and second individual filters of differing wavelengths such that the first sensor is responsive to shorter wavelengths, the second sensor is responsive to longer wavelengths, and both sensors view the same area simultaneously.

Abstract: A pyrometer for determining the temperature of a surface in the presence of reflected radiation has two infrared radiation sensors, each responsive to different wave length, positioned to receive radiation from the surface. An adjustment factor is developed from sensor response signals when reflected radiation and surface temperatures are the same, and is combined with sensor response characteristics over a range of surface and sensor indicated temperatures to develop a correction factor which when multiplied by the indicated temperature provides the actual surface temperature.

Abstract: A circuit for determining the duration range of each incursion by a variable signal on one side of a selected level uses a comparator with a reference crossing level to develop a squared waveform pulse output. Each pulse is integrated and the value gated to a plurality of comparators. The comparators have inhibit interconnections and reference inputs for the desired ranges.

Abstract: A surface roughness analyzer uses a varying electrical output of a transducer attached to a stylus scanning a surface to provide a pulse train having a pulse duration representative of the peak support width established when the output crosses a reference level. During a scan an average arithmetic average roughness is indicated and the pulses are counted which occur within selected ranges of peak support width. Readouts at the end of the scan include average arithmetic average surface roughness, bearing area and peak count with reference levels based on roughness range or bearing area.

Abstract: A weld inspection system uses fluoroscopic flaw detection particularly sensitive to volumetric type weld flaws and ultrasonic flaw detection particularly sensitive to planar type weld flaws. Both inspections are performed simultaneously throughout the pipe length. Each system marks the pipe with a distinguishing mark to identify the location of the flaw detected by that system. The fluoroscopic system is a high resolution system, the ultrasonic system avoids detection of minor non-rejectable variation in weld bead geometry and is calibrated to a desired sensitivity level.