Abstract: The disclosure relates to a measurement of the wall thickness of samples such as pipes, containers or panels in which the interior or underside is inaccessible and to a measurement of the layer thickness of coatings or linings of the samples. Disclosed are special measuring arrangements using ultrasonic transmitters and ultrasonic receivers with pitch-catch and pulse-echo configurations, and the associated method for determining the wall thickness without prior knowledge of the sound velocity in the sample. Measuring individual layer thicknesses of a multilayered system without prior knowledge of their sound velocities is also disclosed. The method and the measuring arrangement allow the wall thickness to be measured independently of the knowledge of the sound velocity of the sample. This reduces the measurement uncertainty for the wall thickness and inner diameter of the pipe and thus reduces the measurement uncertainty for a clamp-on ultrasonic flow meter.

Abstract: A method and an arrangement for ultrasonic flow measurement according to the transit-time method is provided for accurate and non-invasive flow measurement independent of the viscosity. At least one sound transducer pair is provided that has a clamp-on ultrasonic transducer operating in transmitting operation and a clamp-on ultrasonic transducer operating in receiving operation. The cross-section of a measurement tube through which a gaseous or liquid medium flows is substantially a pentagon having a base side and having sides adjacent at right angles and having sides adjacent thereto and lying opposite the base side, which include an angle of less than 180°. The sound transducer pair is arranged on the base side in order produce first sound paths. Because of flattening of the vertex lying opposite the base side, the same sound transducer pair additionally produces a second sound path.

Abstract: A method and an arrangement for ultrasonic clamp-on flow measurement with the aid of an off-center sound path measurement via clamp-on ultrasonic transducers being fastened to an intermediate piece of a process pipe. Center sound paths as well as off-center sound paths are taken into account for the flow measurement via the arrangement and method. The arrangement for measuring flow includes a process pipe, through which a liquid or gaseous process medium flows, and an acoustic transducer pair and second clamp-on ultrasonic transducer operating in receive mode is disposed on the process pipe where two bodies are disposed on the inner wall of the process pipe to aid the off-center measurement.

Abstract: A method and to an arrangement for ultrasonic flow measurement according to the transit-time method is provided for accurate and non-invasive flow measurement independent of the viscosity. At least one sound transducer pair is provided that has a clamp-on ultrasonic transducer operating in transmitting operation and a clamp-on ultrasonic transducer operating in receiving operation. The cross-section of a measurement tube through which a gaseous or liquid medium flows is substantially a pentagon having a base side and having sides adjacent at right angles and having sides adjacent thereto and lying opposite the base side, which include an angle of less than 180°. The sound transducer pair is arranged on the base side in order produce first sound paths. Because of flattening of the vertex lying opposite the base side, the same sound transducer pair additionally produces a second sound path.

Abstract: The invention relates to a method and an arrangement for an ultrasound clamp-on flow measurement according to the transit-time method. The problem addressed by the invention is to provide a measurement arrangement for clamp-on flow measurement, which enables measurement using only two pairs of acoustic transducers in both reflection configuration and in X configuration, without requiring the acoustic transducer position to be changed when switching between configurations. For the method according to the invention, at least four acoustic transducers are arranged on a measurement pipe, which are controlled in such a way that the flow measurement is performed consecutively in an alternating manner in the X configuration and in the reflection configuration. For this purpose, two acoustic transducers are connected for each transmission-receiving pair for a flow measurement in X configuration, and/or two acoustic transducers are connected for each transmission-receiving pair for two reflection configurations.

Abstract: A method and an arrangement for ultrasonic clamp-on flow measurement with the aid of a measurement of off-center sound path, clamp-on ultrasonic transducers being fastened to an intermediate piece of a process pipe. Due to the method for ultrasonic clamp-on flow measurement on a process pipe, through which a liquid or gaseous process medium flows, center sound paths as well as off-center sound paths are taken into account. The arrangement for measuring flow includes a process pipe, through which a liquid or gaseous process medium flows, and at least one acoustic transducer pair. At least one second clamp-on ultrasonic transducer operating in receive mode is disposed on the process pipe. At least two bodies are disposed on the inner wall of the process pipe.

Abstract: The invention relates to a method and an arrangement for an ultrasound clamp-on flow measurement according to the transit-time method. The problem addressed by the invention is to provide a measurement arrangement for clamp-on flow measurement, which enables measurement using only two pairs of acoustic transducers in both reflection configuration and in X configuration, without requiring the acoustic transducer position to be changed when switching between configurations. For the method according to the invention, at least four acoustic transducers are arranged on a measurement pipe, which are controlled in such a way that the flow measurement is performed consecutively in an alternating manner in the X configuration and in the reflection configuration. For this purpose, two acoustic transducers are connected for each transmission-receiving pair for a flow measurement in X configuration, and/or two acoustic transducers are connected for each transmission-receiving pair for two reflection configurations.

Abstract: A method of ultrasonic clamp-on flow measurement according to the transit time difference method and apparatus for the implementation of the method, wherein the electromechanical transducer element of at least one of the two acoustic transducers is comprised of at least two array elements and a correction factor is determined by comparing the transit times between the acoustic transducers while using different array elements.

Abstract: A measuring head clamp-on device for ultrasonic flow measuring heads includes a guide element for receiving at least one measuring head protective housing for at least one measuring head and includes at least one clamping unit connected to the guide element, and thereto connected clamping device for detachably fastening the guide element to the measuring tube, wherein the guide element is non-positively or positively connected to at least one apparatus for centering and clamping the same on the measuring tube, so that the guide element is oriented and fastened parallel and with a defined distance to the apex of the measuring tube irrespective of the tube diameter.

Abstract: A measuring head clamp-on device for ultrasonic flow measuring heads includes a guide element for receiving at least one measuring head protective housing for at least one measuring head and includes at least one clamping unit connected to the guide element, and thereto connected clamping device for detachably fastening the guide element to the measuring tube, wherein the guide element is non-positively or positively connected to at least one apparatus for centring and clamping the same on the measuring tube, so that the guide element is oriented and fastened parallel and with a defined distance to the apex of the measuring tube irrespective of the tube diameter.

Abstract: The invention relates to a method for calibrating the transmitters of ultrasonic flow meters according to the transit time difference method. The object of the invention is to provide a method for calibrating the transmitters of ultrasonic flow meters, said calibration being able to be carried out independently of the other components of the meter, such as the acoustic transducers and the pipe in which the fluid flow being measured occurs. According to the invention, the measurement signals are generated by means of an artificial simulation of the measurement path. This allows the transmitter to be calibrated independently of the remaining components of the measuring apparatus, such as the measuring tube and the acoustic transducers.

Abstract: A method of ultrasonic clamp-on flow measurement according to the transit time difference method and apparatus for the implementation of the method, wherein the electromechanical transducer element of at least one of the two acoustic transducers is comprised of at least two array elements and a correction factor is determined by comparing the transit times between the acoustic transducers while using different array elements.

Abstract: A transmitted light refractometer allows high measurement accuracy across a broad measurement range, even under difficult measuring conditions. The transmitted light refractometer can be connected to a process simply via a single access. In accordance with advantageous features, the transmitted light refractometer covers a measurement range for all practically relevant media and includes integrated temperature compensation. A reversing optics unit is arranged relative to an illumination optics unit such that the reversing optics unit deflects a parallel beam through the process liquid and a measurement prism into the transmitted light refractometer back to the side from which it was radiated. The illumination optics unit, an imaging optics unit, and a detector plane are arranged on the light radiation side such that only one process access is needed.

Abstract: A transmitted light refractometer allows high measurement accuracy across a broad measurement range, even under difficult measuring conditions. The transmitted light refractometer can be connected to a process simply via a single access. In accordance with advantageous features, the transmitted light refractometer covers a measurement range for all practically relevant media and includes integrated temperature compensation. A deflecting optics unit is arranged relative to an illumination optics unit such that the deflecting optics unit deflects a parallel beam through the process liquid and a measurement prism into the transmitted light refractometer back to the side from which it was radiated. The illumination optics unit, an imaging optics unit, and a detector plane are arranged on the light radiation side such that only one process access is needed.

Abstract: A position difference is created by mutual translation of sound transducers and the associated time difference is measured. Radiating surfaces of both sound transducers are arranged acoustically opposing one another in planes that are parallel to one another. The sound transducers are positioned at a mutual distance x0+xd, and sound transit time t1 between the sound transducers is measured, wherein position x0 is the distance for optimum acoustic coupling of the two sound transducers and xd is the deviation from this position that is designated as the deviation. The sound transducers are repositioned at another mutual distance x0+xd+?x, and the sound transit time t2 between the sound transducers is measured. An acoustic calibration factor Ka is calculated from the distance difference ?x and the time difference ?t=t2?t1 using the formula Ka=?x/?t.

Abstract: The invention relates to a device for coupling ultrasound clamp-on throughflow measuring heads to a high-temperature measuring tube. The invention is characterized in that a thin coupling plate is arranged between the tube wall and the measuring head. As a result, the temperature of the measuring head can be reduced to a maximum acceptable value. The shape of the coupling plate affects the adjustable temperature profile in such a way that the isotherms extend in the tube wall area in a parallel manner in relation to the path length of the sound waves in the measuring head area, thereby minimizing resulting errors in throughflow measurement.

Abstract: The invention relates to a device for coupling ultrasound clamp-on throughflow measuring heads to a high-temperature measuring tube. The invention is characterized in that a thin coupling plate is arranged between the tube wall and the measuring head. As a result, the temperature of the measuring head can be reduced to a maximum acceptable balue. The shape of the coupling plate affects the adjustable temperature profile in such a way that the isotherms extend in the tube wall area in a parallel manner in relation to the path length of the sound waves in the measuring head area, thereby minimizing resulting errors in throughflow measurement.