Rom-News-247.de
Laser-based systems to substitute isotopic and x-ray systems
Datum: Freitag, dem 27. November 2009
Thema: Rom Infos
New system measures independent of material properties
LAP has further enhanced the accuracy of its CALIX sensors in strip gage measuring applications. The systems now reach the same or even superior levels of precision as radiometric systems, which so far have been the most commonly used systems in rolling mills. Thanks to their compactness, the new systems can be easily integrated into existing process lines, without having to take any conversion measures on site. Their operation does not require any radiation protection measures to be taken.
LAP has developed a new generation of laser-based thickness gages, representing a cost-effective alternative to radiometric systems. Comprehensive measurements have shown that the new CALIX sensors operate with a measuring accuracy of +/- 4 µm and a repetition accuracy of +/- 0.4 µm (2 ?) over the complete measurement range of 0.02 - 30 mm.
CALIX systems work entirely independently of the strip properties. Therefore it is not necessary to input any chemistry and density data for the strip or store such information in a database, as required by radiometric methods. This feature prevents any hidden, material-inherent error propagation due to material inhomogeneities in the strip material. "Thickness noise" known from radiometric systems or the source noise occurring with isotopic systems are things of the past.
The high level of measuring accuracy and the compact design make CALIX systems a highly attractive alternative to radiometric systems when building completely new or upgrading existing rolling mills. Due to the moderate expense of the optics and evaluation electronics and the low calibration and maintenance effort, CALIX is a highly cost-effective solution.
As the measuring frame is extremely compact - the system requires a maximum clearance of 400 mm in the rolling direction - existing radiometric systems can be replaced without rebuilding the mill equipment. Existing devices for retracting the frame can be continued to be used.
There is up to 200 mm clearance between the legs of the C-frame, avoiding any risk of collision when measuring wavy material or during strip threading. From now on LAP will deliver the CALIX systems with leg lengths of 1,000 mm. Thus the sensors can cover the center of strip as wide as 2,000 mm. A measuring frame can accommodate several pairs of sensors for different measuring tracks. As an alternative option, it is also possible to use a measuring frame equipped with only one pair of sensors and traverse it across the width of the strip.
LAP has developed the CALIX system for application in cold strip rolling mills. Changing ambient temperatures do not affect the system's measuring accuracy. Even a temperature difference of as high as 50 °K causes a drift of less than 0.5 µm.
The measured distance values are evaluated every 2 ms. This is a major advantage over radiometric systems, which typically operate at a scanning rate of 40 - 60 ms. For a laser-based system this means that of a strip running at 300 m/min a measured value can be delivered every 10 mm. Effects such as roll eccentricity can be more easily recognized than by a radiometric system, which takes a measurement only every 200 to 300 mm. The laser system also generates high-resolution thickness profiles of the produced strip length. The high measuring frequency makes the systems suitable to be integrated into fast acting gage control.
CALIX operates on the principle of laser triangulation, which is based on absolute measurements. The thickness of the strip is simply calculated from the difference between the distances measured by two lasers. This makes the measurement independent of the material of the measured product and dispenses with the need to store and update comprehensive charts of chemistry and density data. Thus errors due to wrong data entry are reliably precluded.
The systems owe their extremely high measuring accuracy to LAP"s special arrangement of several CCD line scan cameras in one system. Thanks to the applied technique, the same accuracy is achieved over the complete range. Moreover, the scanning range does not need to be changed for different strip thicknesses.
CALIX does not require any regular on-site calibration during running operation. This also eliminates the need to have calibrated adjusting pieces for different steel grades. Nor is it necessary to perform semi-automatic calibration of the system as required by other optical systems, where during breaks in production a sheet of metal is moved into the light path by a cantilever for calibration of the gaging system.
Digital signal processing equipment adapts the data evaluation process to the specific surface structure of the strip. This feature makes CALIX equally suitable for measurements on matt and high-gloss surfaces. As the laser power is as low as 1 mW (laser class 2), it is not necessary to assign a radiation safety officer. Likewise CALIX reduces to zero the need to take protective measures against ionizing radiation.
LAP has already delivered the first CALIX sensors for inline gage measurement to a customer in the USA. The systems are scheduled to go on stream in early 2010.
About LAP
For 25 years LAP has supplied laser-based systems for high-precision measurements of geometric dimensions, such as position, width, thickness, length, diameter and flatness, in industrial production. LAP systems excel at providing ultra-precise measurement results under harshest operating conditions. Hundreds of LAP systems are tried and tested every day in steel and rolling mills.
Among the customers of the company, which today employs more than 150 people, are leading steel makers such as ArcelorMittal, Baosteel, Posco, ThyssenKrupp Steel and Vallourec & Mannesmann.
The LAP staff takes care of the company?s worldwide customers from the headquarters in Lüneburg/Germany and through an international network of branches and technical agencies.
LAP GmbH
Dr. Axel Schulz
Zeppelinstraße 23
21337 Lüneburg
+49.4131.951195
+49.4131.951196
www.lap-laser.com
Pressekontakt:
V.I.P. Kommunikation
Dr.-Ing. Uwe Stein
Kackertstraße 4
52072
Aachen
Reinhardt@vip-kommunikation.de
+49.241.89468-55
http://vip-kommunikation.de
New system measures independent of material properties
LAP has further enhanced the accuracy of its CALIX sensors in strip gage measuring applications. The systems now reach the same or even superior levels of precision as radiometric systems, which so far have been the most commonly used systems in rolling mills. Thanks to their compactness, the new systems can be easily integrated into existing process lines, without having to take any conversion measures on site. Their operation does not require any radiation protection measures to be taken.
LAP has developed a new generation of laser-based thickness gages, representing a cost-effective alternative to radiometric systems. Comprehensive measurements have shown that the new CALIX sensors operate with a measuring accuracy of +/- 4 µm and a repetition accuracy of +/- 0.4 µm (2 ?) over the complete measurement range of 0.02 - 30 mm.
CALIX systems work entirely independently of the strip properties. Therefore it is not necessary to input any chemistry and density data for the strip or store such information in a database, as required by radiometric methods. This feature prevents any hidden, material-inherent error propagation due to material inhomogeneities in the strip material. "Thickness noise" known from radiometric systems or the source noise occurring with isotopic systems are things of the past.
The high level of measuring accuracy and the compact design make CALIX systems a highly attractive alternative to radiometric systems when building completely new or upgrading existing rolling mills. Due to the moderate expense of the optics and evaluation electronics and the low calibration and maintenance effort, CALIX is a highly cost-effective solution.
As the measuring frame is extremely compact - the system requires a maximum clearance of 400 mm in the rolling direction - existing radiometric systems can be replaced without rebuilding the mill equipment. Existing devices for retracting the frame can be continued to be used.
There is up to 200 mm clearance between the legs of the C-frame, avoiding any risk of collision when measuring wavy material or during strip threading. From now on LAP will deliver the CALIX systems with leg lengths of 1,000 mm. Thus the sensors can cover the center of strip as wide as 2,000 mm. A measuring frame can accommodate several pairs of sensors for different measuring tracks. As an alternative option, it is also possible to use a measuring frame equipped with only one pair of sensors and traverse it across the width of the strip.
LAP has developed the CALIX system for application in cold strip rolling mills. Changing ambient temperatures do not affect the system's measuring accuracy. Even a temperature difference of as high as 50 °K causes a drift of less than 0.5 µm.
The measured distance values are evaluated every 2 ms. This is a major advantage over radiometric systems, which typically operate at a scanning rate of 40 - 60 ms. For a laser-based system this means that of a strip running at 300 m/min a measured value can be delivered every 10 mm. Effects such as roll eccentricity can be more easily recognized than by a radiometric system, which takes a measurement only every 200 to 300 mm. The laser system also generates high-resolution thickness profiles of the produced strip length. The high measuring frequency makes the systems suitable to be integrated into fast acting gage control.
CALIX operates on the principle of laser triangulation, which is based on absolute measurements. The thickness of the strip is simply calculated from the difference between the distances measured by two lasers. This makes the measurement independent of the material of the measured product and dispenses with the need to store and update comprehensive charts of chemistry and density data. Thus errors due to wrong data entry are reliably precluded.
The systems owe their extremely high measuring accuracy to LAP"s special arrangement of several CCD line scan cameras in one system. Thanks to the applied technique, the same accuracy is achieved over the complete range. Moreover, the scanning range does not need to be changed for different strip thicknesses.
CALIX does not require any regular on-site calibration during running operation. This also eliminates the need to have calibrated adjusting pieces for different steel grades. Nor is it necessary to perform semi-automatic calibration of the system as required by other optical systems, where during breaks in production a sheet of metal is moved into the light path by a cantilever for calibration of the gaging system.
Digital signal processing equipment adapts the data evaluation process to the specific surface structure of the strip. This feature makes CALIX equally suitable for measurements on matt and high-gloss surfaces. As the laser power is as low as 1 mW (laser class 2), it is not necessary to assign a radiation safety officer. Likewise CALIX reduces to zero the need to take protective measures against ionizing radiation.
LAP has already delivered the first CALIX sensors for inline gage measurement to a customer in the USA. The systems are scheduled to go on stream in early 2010.
About LAP
For 25 years LAP has supplied laser-based systems for high-precision measurements of geometric dimensions, such as position, width, thickness, length, diameter and flatness, in industrial production. LAP systems excel at providing ultra-precise measurement results under harshest operating conditions. Hundreds of LAP systems are tried and tested every day in steel and rolling mills.
Among the customers of the company, which today employs more than 150 people, are leading steel makers such as ArcelorMittal, Baosteel, Posco, ThyssenKrupp Steel and Vallourec & Mannesmann.
The LAP staff takes care of the company?s worldwide customers from the headquarters in Lüneburg/Germany and through an international network of branches and technical agencies.
LAP GmbH
Dr. Axel Schulz
Zeppelinstraße 23
21337 Lüneburg
+49.4131.951195
+49.4131.951196
www.lap-laser.com
Pressekontakt:
V.I.P. Kommunikation
Dr.-Ing. Uwe Stein
Kackertstraße 4
52072
Aachen
Reinhardt@vip-kommunikation.de
+49.241.89468-55
http://vip-kommunikation.de
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