Metal production and processing

Coil diameter

Rolled strips in the metal industry are wound on coils for transport. For the later processing when the coils are unwound, it is important to know how much material has already been unrolled. This task is simple to solve by using an optoNCDT ILR optical length sensor. It continuously measures onto the surface of the coil and thus records the diameter. The diameter of the coil reduces due to the unwinding which is measured using the increase in distance from the coil surface to the sensor. Using the coil thickness, the material length can be recalculated using specific algorithms.

Coil unwinding

Rolled strips in the metal industry are wound on coils for transport. For the later processing when the coils are unwound, it is important to know how much material has already been unrolled. This task is simple to solve by using an optoNCDT ILR optical length sensor. It continuously measures the distance from the surface of the coil to the centre. The thickness of the coil reduces due to the unwinding which is measured using the increase in distance from the coil surface to the sensor. Using the coil thickness, the material length can be recalculated using specific algorithms.

Measuring and inspecting laser welding seams

Fully automatic welding units can be found in numerous industrial areas. Quality control in the form of a 100% inspection is indispensable in order to achieve defect-free weld seams. Laser profile sensors from Micro-Epsilon monitor the weld seam and immediately detect defects as well as the completeness of the width and height profile of the weld.

Double sheet detection before pressing

Before shaped sheets are fed into the press, laser-optical displacement sensors are used, which enable double sheet detection. Two sensors are mounted above and below the continuous sheets and provide a thickness value regardless of the exact position of the sheets.

Thickness measurement of metal strips

When measuring the thickness of metal strips, optical methods based on laser triangulation have numerous advantages compared with other methods. They measure without contact and therefore without wear. Moreover, independently of the condition of the material it is possible to carry out an exact geometrical measurement in relation to the strip surface. Micro-Epsilon offers robust measuring systems as C-frames and O-frames which operate independently of the alloy.

Measurement of the zinc strip colour in the production plant

In the production of high-quality material strips and boards made out of titanium zinc, the surfaces receive specific treatment. Therefore, the colouring of the zinc products is already determined during the production process.

Weld seam inspection on pipes

A perfect weld seam is essential in a leak tight pipe. scanCONTROL laser scanners are therefore used during spiral welding to align the weld flanks. This results in a much more reliable welding process. The long base distance of 600mm and the protective housing for the sensor are also important here.

Acquisition of the internal diameter of tubes

An important criterion for the quality or the wear of tubes in industrial applications is the dimensional conformance of the internal diameter over the complete length. Where high demands are made on accuracy, a quick and reliable recording of the data must be ensured, because, for example, wear measurements must be carried out in the chemical industry on pipes which are already installed, i.e. with the plant shut down. Two pairs of sensors record two tracks offset by 90° in one measurement step.

Strip width when trimming metal strips

As different widths are frequently required during the production of metal strips, the strips must be trimmed after the rolling process and both the cutters must be movable electrically. The distance is now measured by difference measurement using laser sensors from Micro-Epsilon so that compliance with the target dimensions no longer has to be checked manually as was the case previously. Two optoNCDT sensors are used for this.

Weld seam tracking for pipeline inspection

Defective weld seams are often the reason for leaks on pipelines. Therefore, the seams are inspected on the outside after the welding with the profile scanner scanCONTROL. In doing so, the scanner is positioned in a testing device on the pipe. After the manual alignment, the scanner automatically inspects the weld seam and centres itself automatically on the pipe in doing so.

High precision pipe measurement

High precision pipe measurement Pipes, fittings and sleeves are inspected using random sampling for their dimensional accuracy in a special system. Sensors of the optoNCDT 1700 series rotate mounted on a plate. The laser beam is deflected by 90° by an adjustable mirror for the measurement. The system produces a detailed thickness profile of the target using the difference method.

Aluminium rim dimension

Maximum quality is required for the production of aluminium rims so that the necessary smooth running is achieved in the subsequent use. In contrast to tactile methods, laser scanners from the Micro Epsilon scanCONTROL series are used for this. These sensors inspect the rims for all geometric defects in an integrated tester. Therefore, a 100% in-line quality control is achieved.

Roller clearance

The distance of both rollers from each other or from the roller to the support surface is the crucial dimension for rolling processes for metals, plastics or other materials. In the case of sensitive processes and high material accuracies, the clearance must be checked constantly so that imminent rejection is avoided. The contacting inductive and the non-contact methods are suitable for this. In the case of contacting methods, the sensor is mounted on the outside on the roller guide. The change in clearance is transmitted to a plunger whose position change is measured by the inductive sensor. In the case of the non-contact method, the roller is between the transmitter and receiver of an optical micrometer. The emitted light curtain is partially covered by the roller. The remainder reaches the receiver through the gap. The gap can be calculated based on the light quantity measurement.

Recommended sensor technology

Optical and Laser Micrometers

Coil edge

Rolled sheets in the metal industry are wound on coils for transport. It is important that directly before and also after the coiling, to check the position and the edge condition of the metal strip. optoCONTROL optical micrometers are used for this. If the edge of the coil is within the measuring range during the winding or unwinding, the position and the edge structure can be determined from this. This technique ensures that the coil is wound correctly and also that the correct metal strip quality has been delivered for the unwinding.

Recommended sensor technology

Optical and Laser Micrometers

Temperature measurement in the hot rolling mill

In the milling line, the forming temperature between the individual rolls is measured continuously. Micro-Epsilon's non-contact infrared pyrometers measure with a short response time and from a safe distance. For the different metals and temperature ranges, IR temperature sensors and thermal cameras with different wavelengths are available.

Tempering - temperature measurement

Stresses can occur during induction hardening which can be counteracted by heating up again to the tempering temperature. However, temperatures lower than those used for hardening are involved. The temperatures are measured with pyrometers from Micro-Epsilon.

Temperature measurement of molten metal

Temperature monitoring of liquid metal is important to maintain the corresponding process temperature during casting. With the thermoIMAGER TIM M05, Micro-Epsilon offers the right spectral range as well as a continuous measuring range of from 900 °C to 2000 °C. Due to the high frame rate of 1 kHz and the high optical resolution, thermal images can be recorded quickly and reliably.

Weld seam profile

Welding robots which perform the joining automatically are often used for joining metals. For visible parts, the weld seam must satisfy certain optical criteria; for example, there must be no remaining welding beads. A laser scanner is installed directly after the welding head for this. It measures all the weld seams made and arranges for the robot to make corrections if necessary.

Aluminium thickness

It is important to know the thickness of the plates for the manufacture of aluminium plates. The non-contact profile measuring system measures the profile of the plates using a capacitive sensor. At the same time, the width of the plate is determined during the measurement. The reversing rolling stand and the following roller stands can be better adjusted using the data obtained. The system is integrated in the existing roller track. Installed directly before the cropping shear where the plate is stationary for the cut, the production process is not impaired.

Recommended sensor technology

Non Contact Measurement Systems

Micro-Epsilon UK Ltd
No.1 Shorelines Building
Shore Road
Birkenhead
CH41 1AU
(for Sat Nav use CH41 1AW)
info@micro-epsilon.co.uk
+44 151 355 6070
+44 151 355 6075