Abstract: An arrangement for ultrasonically measuring the elastic properties of a moving web includes an ultrasonic wave generator and at least two ultrasonic wave detection devices which receive the generated ultrasonic wave without contacting the web. The received signal is processed such that the desired properties if the moving web can be determined.

Abstract: A method for measuring the size and magnitude of pinholes in a sheet of paper, comprising placing a test sheet of paper on top of a backing sheet and spreading ink, oil or stain across the test paper. Uniform pressure is applied to the test paper in sufficient magnitude to force the ink through any pinholes in the test paper and to create an imprint on the backing sheet. The backing sheet is then removed and allowed to dry. The imprint is then analyzed to determine the number and size of the pinholes in the test paper.

Abstract: In a photo-acoustic gas sensor having a measuring cell, a lamp, a photo-diode, a gas-permeable diaphragm and a microphone, a device is included for monitoring the gas-permeable diaphragm and the microphone. The device is operated in an explosion-proof manner. Intentionally, for diagnostic purposes, an artificial pressure modulation is generated in the measuring cell. The pressure modulation is converted by the microphone into electrical monitoring signals which are amplified by an amplifier circuit and assigned to preset ranges by a microprocessor, for determining the functional condition of the diaphragm and the microphone, and of microphone sensitivity. Depending on the range assigned to the monitoring signal, an output signal is generated indicating a fault in the microphone and/or the diaphragm. In the event of long-term drift in microphone sensitivity, a calibration is performed in which gas concentration values are re-calculated and stored in an EEPROM.

Abstract: An audible waveform system is provided that senses a parameter relating to the ventilation of a patient. The system produces short bursts of sound of a predetermined frequency as the changes occur in that parameter based on certain increments of change. The bursts themselves are preferable at a frequency that is the same for equal pressures but increases and decreases in frequency as the parameter increases or decreases, respectively. In the preferred embodiment, the system provides an audible waveform based on the pressure in the patient airway so that the clinician can receive information relating to that waveform conveniently and without taking attention away from other monitors and/or alarms.

Abstract: The invention relates to a method and an apparatus for recording causes of faults in products, in which the faults are recorded and counted. The recorded faults are represented according to selected parameters, so that a fault pattern is obtained. From this, a reference to the cause of the fault is produced.

Abstract: An apparatus for measuring the tensile strength of a textile fabric comprises a measuring system having electromagnet, a mass capable of being held in place by the electromagnet, a piezoelectric force sensor connected to said mass, and a rounded-off impact body. By de-energizing the electromagnet, the impact body free-falls onto the textile fabric, which is held in place beneath the impact body under tension. The impact force detected by the sensor is converted to a form with which a computer can compute the tensile strength of the fabric. A series of measurements can be made of a length of fabric advanced through the apparatus in successive stages.

Abstract: A non-destructive, non-contact testing apparatus and method which generally includes an ultrasonic signal generator for inducing one or more ultrasonic signals in a material and an optical interferometer that includes a laser for illuminating a section of the material and for detecting beat frequencies resulting from reflected light from the material. Deformations in the material as a result of the ultrasonic signal cause the beat frequency to be shifted as a result of the Doppler effect. Such differences in the beat frequency are detected by the system and used as an indication of a characteristic of the material.

Abstract: The invention relates to a system for measuring ultrasonically the elastic properties of a moving paper web. A noise type ultrasonic sound wave is generated by an ultrasonic sound generating device in the web at an excitation point. A reference ultrasonic wave reradiated into the air from the excitation point is indicated. A pick-up device is provided for receiving ultrasonic sound reradiated from the paper web at a predetermined distance form the location of the sound generating device. The ultrasonic sound generating device and the reference ultrasonic receiving device are provided on the same side of the paper web. At least one of these two kinds of devices includes a number of elements provided symmetrically in relation to the other device.

Abstract: A method is described for determining and evaluating physical characteristics of a material. In particular, the present invention provides for determining and evaluating the anisotropic characteristics of materials, especially those resulting from such manufacturing processes as rolling, forming, extruding, drawing, forging, etc. In operation, a complex ultrasonic wave is created in the material of interest by any method. The wave form may be any combination of wave types and modes and is not limited to fundamental plate modes. The velocity of propagation of selected components which make up the complex ultrasonic wave are measured and evaluated to determine the physical characteristics of the material including, texture, strain/stress, grain size, crystal structure, etc.

Abstract: A temperature compensation method for a microprocessor based electro-pneumatic converter device including an initial calibration sequence, a compensation sequence, and an operation sequence. Linearization of an electro-pneumatic positioner including the steps of adjusting the positioner feedback linkage until a predetermined reference position is attained, reading a position feedback value and determining the required feedback linearization value to achieve a linear relationship between the output/input. A calibration method and a configuration method independent of calibration for a microprocessor based electro-pneumatic converter device including an initial calibration sequence, a configuration sequence, and an operation sequence.

Abstract: Disclosed is a method of determining motion-control and damping characteristics for a resilient, multi-element elastomeric belt used in a servo system, yet without need to test in a use environment, this method including: stretching a prescribed length L of the belt between a pair of guide pulleys mounted on a frame with prescribed tension; attaching a prescribed test weight on this length at a prescribed test-distance L.sub.1 from one of the guide pulleys; shaking the frame at resonance frequency, sinusoidally; while determining the amplitude of excursion for the weight and the frame; then changing distance L.sub.1 and repeating the foregoing operations one or more times.

Abstract: A method of monitoring bagginess of a web transverse to a longitudinal direction of the web is disclosed. The method includes projecting a first reference light onto a front face of the web transverse to the web, and projecting a first measurement light onto the front face of the web non-perpendicular to the front face and transverse to the web. The longitudinal distance on the front face of the web between a point along the first reference light and a corresponding point along the first measurement light are compared to determine bagginess of the web. A method of monitoring bagginess of a web in the longitudinal direction of the web is also disclosed.

Abstract: An embossed cold rolled metal (e.g. steel) sheet for use in manufacturing appliances and method of making same wherein the surface attributes of the embossed sheet are optimized to improve corrosion resistance of the painted product, promote uniform paint coverage of the sheet surface, reduce paint consumption, enable repainting without loss of pattern crispness, and provide consistent and aesthetically pleasing appearance of the painted sheet. The embossed sheet has a plurality of plateaus and impressions defined therein in a manner such that the arithmetic average surface roughness (Ra) of the plateaus is from about 50 to 100 microinches, the maximum impression depths over a given area are from about 0.0025 to 0.0032 inches, the impression walls define maximum slopes of from about 8-17 degrees, and there are no sharp corners or ridges at the transition points between plateaus and impressions.

Abstract: A method for improving the accuracy of measuring the velocity and time of flight of ultrasonic signals through moving web-like materials such as paper, paperboard and the like, includes a pair of ultrasonic transducers disposed on opposing sides of a moving web-like material. In order to provide acoustical coupling between the transducers and the web-like material, the transducers are disposed in fluid-filled wheels. Errors due to variances in the wheel thicknesses about their circumference which can affect time of flight measurements and ultimately the mechanical property being tested are compensated by averaging the ultrasonic signals for a predetermined number of revolutions. The invention further includes a method for compensating for errors resulting from the digitization of the ultrasonic signals. More particularly, the invention includes a method for eliminating errors known as trigger jitter inherent with digitizing oscilloscopes used to digitize the signals for manipulation by a digital computer.

Abstract: A measuring device scanning from edge to edge of a continuously fed sheet includes two sensing heads spaced apart from the sheet by air cushions whose thickness is not influenced by pressure of supplied air and is subjected to an invariable approaching gravimetric force. The air cushions are preferably formed of air jets from calibrated holes at the inside of both sensing heads, each of said holes being surrounded by annular barriers with circular rims. While the approaching force applied to the upper head is given by the own weight of the latter, the corresponding opposed force on the lower head is provided by a pressure regulator of internal air at the inside of the lower sensing head.

Abstract: A process and device for scanning a moving fiber sliver in a textile machine to measure the thickness of the sliver has a movably mounted scanning element which is pressed against the fiber sliver and has a contact pressure against the sliver. The degree of movement of the movable scanning element indicates changes in the thickness of the moving fiber sliver. An adjusting element is connected to the movably mounted scanning element and maintains a constant contact pressure of the scanning element against the sliver over the entire measuring range of the movable scanning element.

Abstract: Sweating hot plate apparatus simulating the thermoregulatory behavior of human skin and related method for predicting fabric comfort level with the apparatus. Fabric is placed on the top surface of the apparatus, and selected constant inputs of power flux and water flow are supplied to the apparatus, whereby the surface temperature of the apparatus changes and closely approximates the skin temperature of human subjects having levels of heat generation and sweat production corresponding at the same levels of power flux input and water flow input, respectively.

Abstract: The invention relates to an apparatus for light fastness testing comprising a light source, means for dividing ultraviolet and visible light from infrared rays, means to direct the visible component of light into spherical cavity, and means to mount test samples in apertures in said cavity.

Abstract: A caliper sensor of the opposing contact type, wherein are provided target supporting spherical surfaces comprising at least three spherical surfaces disposed on a periphery of a target facing plane of a sliding surface and a plane determined by the tops of each spherical surface and in contact in parallel with a measurement reference plane above the target; and contact spherical surfaces for the reference plane outside the target facting plane of the sliding surface, whose number is equal to or greater than that of the relevant target supporting spherical surfaces and the tops of each spherical surface having a height about equal to the relevant target supporting spherical surfaces, so that contaminants are steered away from the tops of the spherical surfaces and the measurement process is thereby unaffected by the contaminants for a long period of time.

Abstract: An improved system for measuring the velocity of ultrasonic signals within the plane of moving web-like materials, such as paper, paperboard and the like. In addition to velocity measurements of ultrasonic signals in the plane of the web in the MD and CD, one embodiment of the system in accordance with the present invention is also adapted to provide on-line indication of the polar specific stiffness of the moving web. In another embodiment of the invention, the velocity of ultrasonic signals in the plane of the web are measured by way of a plurality of ultrasonic transducers carried by synchronously driven wheels or cylinders, thus eliminating undue transducer wear due to any speed differences between the transducers and the web. In order to provide relatively constant contact force between the transducers and the webs, the transducers are mounted in a sensor housings which include a spring for biasing the transducer radially outwardly.

Abstract: A method of compensating forces of force components resulting from horizontal movements of the rolls in roll stands for hot-rolling and cold-rolling of flat products, wherein the roll stands are equipped with work rolls and with one or more back-up rolls, with hydraulic adjusting units and with force measuring devices on the opposite side of the roll gap and with hydraulic devices for the horizontal displacement of the work rolls. The pressures in the two adjusting cylinders are utilized for determining the rolling forces on one side of the roll gap and the forces indicated by the force measuring devices are utilized for determining the rolling forces on the opposite side of the roll gap, and all axial forces in the stand are computed during the rolling operation by including the axial forces of the work rolls which can be determined through the pressures in the displacement cylinders of the work rolls.

Abstract: A tester for measuring a durability of a knitted yarn portion in which at least two sets of yarns, including a set of first yarns and a set of second yarns, are intersected, the tester includes: a first holding unit holding ends of the two sets of yarns at first positions that are relative to the knitted yarn portion; a second holding unit holding opposite ends of the two sets of yarns at second positions that are relative to the knitted yarn portion; and a position adjusting unit, connected to the first holding unit and the second holding unit, allowing at least one of the first positions and the second positions, relative to the knitted yarn portion, to be moved to other positions, thus varying an intersecting angle of the yarns of the knitted yarn portion.

Abstract: A device for measuring the thickness of objects to be handled in mail processing machines, particularly collating machines, inserters and the like, has a relatively-stationary back-up part; a gripper jaw; a rotating axis for mounting the gripper jaw pivotably in relation to the back-up part, whereby an object to be handled is engagable between the gripper jaw and the back-up part; an actuator system operatively connected between the back-up part and the gripper jaw for generating pivotal movement of the gripper jaw between an engagement position and an open position in relation to the back-up part; a movement-transmission part fastened to the rotating axis; and, a measuring device provided operatively between the movement-transmission part and the back-up part, the measuring device providing position-detector signals corresponding to predetermined pivotal positions of the gripper jaw in relation to the back-up part.

Abstract: A dough sheet sensor comprises a sensing roller, a pivot, a roller support arm and an adjustable counterweight. The sensing roller is displaceable in a first direction as a function of tension in a dough sheet. The roller support arm supports the sensing roller and is attached to the pivot. The adjustable counterweight is attached to the roller support arm and positioned opposite to the pivot with respect to the sensing roller for counterbalancing the sensing roller and the roller support arm. A non-contact distance sensor is operably coupled to the sensing roller through a measurement gap. The measurement gap has a length that varies with the sensing roller displacement.

Abstract: A method and apparatus for determining the mass density of a moving filament is provided. The method includes the steps of providing a filament across two supports, tensioning the filament, inducing a vibration into the filament segment between the supports, reinforcing the vibration using an amplified feedback signal, detecting the vibrational frequency data, processing the data using a fast-fourier transform analysis, and then displaying the frequency. The use of the feedback signal results in a self-tuning resonant loop. Open loop versions may also be used. The apparatus includes a base supporting a fixed support and a transducer which in turn supports a moveable support. The transducer vibrates the moveable support transversely to the direction of travel of the filament, thereby inducing a transverse vibrational mode. The output of the transducer is amplified and used to drive a second amplifier to produce a self-tuning resonant loop.

Abstract: The invention relates to a method and apparatus for dynamic determination of the thickness and/or basis weight of moving material under test. The material under test is exposed to a focused ultrasound filed with high sound intensity, whereby the sound fraction coming from the material under test is detected directly in the near filed, i.e. at a distance smaller than or equal to the acoustic wavelength used, and evaluated for determining the thickness and/or basis weight. The near-field measurement preferably takes place with continuous sound and in transmission.

Abstract: A method and apparatus for processing a longitudinally traveling web of material using a sheet treating device positioned in a transverse direction relative to the web. The sheet treating device having a plurality of individually controllable zones for controlling a target parameter of the web, for example, the thickness, bulk, dampness, smoothness or sheen of the web. In conjunction with the sheetmaking device, a measuring instrument for measuring an actual value of the target parameter is placed downstream of the sheet treating device. An actual profile that is determined by the actual values is compared with a desired profile, and the zones of the sheet treating device are adjusted such that the discrepancies between the two profiles are minimized. To improve the matching of the actual profile to the desired profile even further, the web and/or the sheet treating device are shifted relative to the other in the transverse direction to minimize the discrepancies between the two profiles.

Abstract: This invention relates to an apparatus and method for identifying periodic roughness variations on a paper surface. Such devices of this type, generally, collect topography data from the paper surface, analyze the data, and compare the data with known signature topographies of paper machine clothing and equipment to determine the location in the paper manufacturing process where the periodic roughness variations on the paper surface are being produced.

Abstract: A method and apparatus for determining the flatness of a sheet material, and for determining the lateral alignment stability of a web or sheet material. The method for determining the flatness of a sheet material includes subjecting a portion of the sheet material disposed between two rollers to a longitudinal tension insufficient to remove internal compressive strains in the longitudinal direction, sensing by non-contact means the distance from a reference plane to the sheet material, and determining a cross-sectional profile of the portion.

Abstract: A method and apparatus are provided for monitoring a fabric. An acoustic probe generates acoustic waves relative to the fabric. An acoustic sensor, such as an accelerometer is coupled to the acoustic probe for generating a signal representative of cavitation activity in the fabric. The generated cavitation activity representative signal is processed to indicate moisture content of the fabric. A feature of the invention is a feedback control signal is generated responsive to the generated cavitation activity representative signal. The feedback control signal can be used to control the energy level of the generated acoustic waves and to control the application of a cleaning solution to the fabric.

Abstract: A method of determining strength and related mechanical properties of paper and similar products, both on-line and off-line using a continuous ultrasonic swept frequency wave transmission and reception system. The invention also provides an apparatus for measuring the strength and related mechanical properties of paper.

Abstract: A laboratory-scale device for assisting in the simulation of heat setting conditions includes a pair of laterally spaced-apart flexible heat-resistant cords (e.g., formed of aramid fibers) tensioned between forward and rearward rigid cross-support bars. At least one rigid tensioning bar is provided parallel to the support cords and extending between the cross-support bars so as to maintain the desired tension on the flexible heat-resistant cords. The tensioning bar thus allows for manual or automated lateral winding of the synthetic heat-settable fibers or yarns about the spaced-apart heat-resistant cords during preparation of the device for a laboratory test run. The tensioning bar may thereafter be removed once the device has been secured in position with the laboratory heat-setting oven. In such a manner, therefore, various effects on heat-setting conditions simulating can be investigated.

Abstract: The measurement of moisture content in granular materials is ordinarily a difficult measurement to make. The invention of this application sets forth a new method and apparatus for measuring moisture content in a wide variety of materials by means of application of an apparatus that makes measurement of moisture content independent of density of the material measured, and thereby unaffected by ambient conditions. The apparatus also allows the practitioner of this invention to readily and accurately measure moisture content.

Abstract: An ultrasonic method and system are provided for monitoring a fabric to identify a defect. A plurality of ultrasonic transmitters generate ultrasonic waves relative to the fabric. An ultrasonic receiver means responsive to the generated ultrasonic waves from the transmitters receives ultrasonic waves coupled through the fabric and generates a signal. An integrated peak value of the generated signal is applied to a digital signal processor and is digitized. The digitized signal is processed to identify a defect in the fabric. The digitized signal processing includes a median value filtering step to filter out high frequency noise. Then a mean value and standard deviation of the median value filtered signal is calculated. The calculated mean value and standard deviation are compared with predetermined threshold values to identify a defect in the fabric.

Abstract: A method and a device for compensating and equalizing the tension forces across the width of a moving web makes use of a tension compensation roll, which is pivotably supported, and rotatable around a pivotal axis. In the presence of a difference in the tension force across the width of the moving web, the tension compensation roll is pivoted via gears with teeth to an extent such that the tension forces in both halves of the web are equalized.

Abstract: An apparatus for measuring sliver thickness in a drawing frame includes a sliver guiding device having converging inner wall faces for bringing a plurality of simultaneously introduced slivers together to form a sliver assembly constituted by side-by-side positioned running slivers arranged in a plane. The apparatus further includes a sensor element and a counterelement laterally contacting the sliver assembly from opposite sides. The sensor element has an operative position and a servicing position; in the servicing position the apparatus outlet is free for access from the exterior. The sensor element is urged into a resilient contact with the sliver assembly whereby the sensor element undergoes excursions upon variation of thickness of the sliver assembly. There is further provided a setting arrangement for selectively positioning the sensor element into the operative or servicing position. The sensor element and the counterelement together define a constriction through which the sliver assembly passes.

Abstract: A sheet material detector has an ultrasonic transmitter and an ultrasonic receiver spaced from one another to permit the passage of a sheet of material therebetween in use. The transmitter and the receiver are mounted on a support to transmit and receive the ultrasonic beam respectively along an axis which is at an acute angle, preferably in the range from 50.degree. to 70.degree., in relation to the plane of the sheet material in use, and each of the transmitter and the receiver includes a hood for shielding the ultrasonic beam against contamination by stray sound waves reflected from extraneous bodies or at the surface of the web or sheet. The detector also includes output signal responsive to the received ultrasonic beam for generating an output signal. One application of the detector is in splice detecting apparatus for detecting the presence of splices in a web of material, and another application is in edge detecting apparatus for indicating the position of an edge of the web or sheet of material.

Abstract: A method for determining the cross-machine shrinkage or expansion profile of a travelling sheet produced in a sheetmaking machine between an upstream location and a downstream location. The method involves marking the sheet at the upstream location with an array of marks at measured, predetermined intervals in the cross-machine direction. The sheet is inspected in the cross-machine direction at the downstream location to measure the spacing of the array of marks. A shrinkage or expansion profile of the travelling sheet is developed based on the changes in the spacing between the array of marks at the downstream location. Apparatus for carrying out the method is also disclosed. The method and apparatus of the present invention permit rapid and precise determination of the sheet shrinkage or expansion profile to allow for better control of property variation across the sheet.

Abstract: An apparatus for detecting breakage of a web of material traversing a machine for feeding the web, and a method for the same. The apparatus includes a housing for mounting three transducers, a first transducer adapted to periodically emit a burst of energy for a period of time, the burst of energy being reflected off an object and producing an echo signal. A second transducer adjacent to the first transducer receives a portion of the echo signal, and a third transducer also adjacent to the first transducer receives another portion of the echo signal. The strongest portion of the echo signal is used to detect whether the web is broken.

Abstract: A method for controlling transverse profiles of a web in a web-manufacturing machine, such as a board or paper machine, and/or being treated in a finishing machine. At least one of a transverse caliper, grammage and moisture profiles of the web is measured either directly or indirectly. Actuators acting upon these profiles are regulated by measurement signals. In order to optimize the quality of the web to be produced, the reel formation, and the runnability of the machine, the transverse tension profile of the web to be manufactured and/or treated is measured. Based on the measurement of the transverse tension profile, set profiles are formed which control the actuator(s) of the profile regulation.

Abstract: A weathering testing machine or the like is provided with improved stabilization of conditions such as temperature and humidity, coupled with more accurate readout from sensors on a moving member in the machine, and other sensors and microprocessors.

Abstract: A sample of fibrous material prepared so that is has a large surface area relative to its weight. The sample is placed on a metal plate and then heated under pressure and successively cooled under pressure. A brush or sweeper then removes substantially all of the fibers left in the sample. If necessary, the sample is dried. The sample now consists of spots on the metal plate. An automatic counting system is used to count the number of spots to determine the sticky characteristic of the fibrous material.

Abstract: A process for transforming a plurality of data points n defining a high resolution profile for a parameter of a sheet material being manufactured into a low resolution profile for control of the parameter is disclosed. The process involves filtering the data points of the high resolution profile using an anti-aliasing filter function to create an intermediate profile and reducing the number of datapoints of the intermediate profile by an integer factor to create the low resolution profile to be used to control the parameter.

Abstract: A device for measuring the warp yarn tension of a woven fabric in a loom, which includes a fixed deviation bar which extends across the entire loom width and cooperates with a device measuring warp yarn tension, the fixed deviation bar having a central or intermediate portion for the fabric under formation, the intermediate portion being of a length less than that of a minimum formable fabric width and being detached from the remaining sections of the bar by thin breaks in the deviation bar. The intermediate portion is supported via at least one load cell. The device is located in the loom to measure the tension of the fabric already woven and prior to its being wound on the winding beam.

Abstract: There are provided a method and an apparatus for determining at least one sheet stretch value of a roll of material. The method comprises the steps of (a) radially marking one side end of the roll from periphery thereof to produce a series of aligned marks along a radius thereof; (b) supporting the roll in such a manner that it is free to rotate, thus allowing relaxation of peripheral layers thereof; and (c) after steps (a) and (b), measuring a lateral shifting value GAP of one of the marks, which is the outermost in periphery of the roll, with respect to an adjacent mark.

Abstract: A contamination gauge for paper manufacturing for detecting the debris on paper includes a hand-held housing having a gripping surface and a plunger carried axially by the housing having a pressure application surface disposed on one end of the plunger for applying a predetermined force. A force exerting element is carried within the interior of the housing for exerting the predetermined pressure when the housing is moved relative to the plunger. An indicator indicates when the housing has moved sufficiently for generating the predetermined amount of pressure. Also a method for testing the propensity of paper rolls to lint debris on printing machines is disclosed.

Abstract: A method and apparatus for non-contact determination of the weight per unit area and the thickness of thin materials. This involves directing an ultrasonic wave at the material and measuring the proportion of sound energy that passes through the material. The process is distinguished by the fact that the time intervals between the ultrasonic pulses are greater than the propagation time. At the receiver only the signals that exceed a certain amount and are shorter in duration than the propagation time are evaluated.

Abstract: A method and apparatus for detecting grain direction in wood by means of microwave radiation. A sample of timber is exposed to a polarized microwave beam emitted by a transmitter (11). A polarized receiver (12) evaluates the microwave energy that has been affected by the timber. The receiver and transmitter polarization planes are locked at either 0 or 90 degrees respect to each other. Both are rotated synchronously and the received energy is plotted versus angle. The energy maximum or minimum gives indication of the grain direction in the timber sample under evaluation.

Abstract: A device for measuring woven fabric stress. The device includes a vacuum chamber having high rigidity; a vacuum pump for reducing the pressure in the vacuum chamber; a pressure gauge; a fabric displacement measuring device; and a fabric stress calculator. The vacuum chamber has an opening for sealing engagement with a surface of a fabric under atmospheric pressure. Upon evacuating the air from the vacuum chamber, the atmospheric pressure against the opposite surface of the fabric distends a portion of the fabric into the vacuum chamber. The measure of fabric distension and the reduced pressure reading in the vacuum chamber are transmitted to the fabric stress calculator, which compares the readings to compute a fabric stress reading.

Abstract: Methods and apparatus are provided for monitoring sliver and yarn characteristics. Transverse waves are generated relative to the sliver or yarn. At least one acoustic sensor is in contact with the sliver or yarn for detecting waves coupled to the sliver or yarn and for generating a signal. The generated signal is processed to identify the predefined characteristics including sliver or yarn linear density. The transverse waves can be generated with a high-powered acoustic transmitter spaced relative to the sliver or yarn with large amplitude pulses having a central frequency in a range between 20 KHz and 40 KHz applied to the transmitter. The transverse waves can be generated by mechanically agitating the sliver or yarn with a tapping member.