Machine building

Automatic height adjustment for material analysis

Laser-induced breakdown spectroscopy (LIBS) performs precise analysis of the atomic composition of different materials. The measurement objects involved are mostly mineral or metallic parts whose surfaces have different gloss levels and which are sometimes extremely tilted.

SECOPTA analytics GmbH uses the ILD1320-100 sensors from Micro-Epsilon in this application to automatically readjust the height of the LIBS sensor head. Particularly with metal samples whose surfaces have different textures such as oxidized spots, the ILD1320 with the ATC feature is a reliable sensor.

Sensor technology applied

Brake disc concentricity

Brake discs are subject to the highest loads in use and are responsible for the safety of vehicles. For this reason alone, brake discs are thoroughly inspected on test benches. Brake discs are checked for various characteristics at a speed of approx. 2000 rpm on special testers. Capacitive sensors are used for checking the geometric characteristics such as concentricity, thickness and wear. As the deformations only occur in the range of hundredths of micrometres, only very precise sensors can be considered for this. The thermoMETER infrared sensors are used for examining the thermal characteristics of the brake disc. The absolute temperature can be monitored with these so that the thermal drift over a long period can be established.

Sensor technology applied

Inspection of rotationally symmetrical parts

The scanCONTROL laser scanner is used for part inspection of various hypoid-tooth components and a digital model of the tooth structure of the component is generated by the measurement system. In this way, the 3D point cloud can be evaluated afterwards according to customer requirements. Previously, this type of inspection was done with manual removal of the part.

Sensor technology applied

Stainless steel tubes for catalyst production

Various shapes of catalysts require that the stainless steel casing has a precise dimensional stability. For round catalysts, stainless steel tubes are therefore subjected to a diameter check in a special measuring system. A confocal sensor measures the distance to the tube, which is rotated through 360°. The outer diameter, the minimum circumscribed circle, and the maximum inscribed circle are directly determined by software calculations. The sensor moves in a horizontal direction, depending on the size of the catalyst.

Sensor technology applied

Shape measurement of rotation symmetrical parts

As rotary pistons for pumps must have very precise surface geometries, the pistons have to undergo 3D shape measurement. The scanCONTROL laser scanner is moved vertically by a linear axis in a special measuring machine. In doing so, the piston rotates in the measuring range of the scanner. A resolution of 3µm is achieved using this.

Sensor technology applied

Thermal milling spindles

Accuracies of a few micrometres must increasingly more often be achieved for the parts machining using machine tools. In doing so, the heat development during the machining and in the tool holder is not insignificant. The thermal expansion of the spindle during the machining can affect the precision so much that the workpiece no longer meets the requirements. The SGS system developed by Micro-Epsilon is used for compensating for the expansion of the tool spindle. The expansion of the spindle is measured using the eddy current based system and in this way precise workpiece machining is made possible.

Sensor technology applied

Measurement of large geometries with precision machines

Measuring complex part geometries is a task for the scanCONTROL laser scanner. Laser scanners are used in the precision machines of EHR in order to perform a component inspection at high resolution and without contact. The special feature is that using a scanner, not only is an inspection possible from the outside but also from the inside.

Sensor technology applied

Overhead conveyor distance

Overhead conveyors which move automatically through the production process on a rail are used for the transportation of many components. A certain minimum distance is required so that components do not collide with each other during the transport. The optoNCDT ILR sensors have the task of maintaining this minimum distance. Attached to each overhead conveyor, they measure the distance to the next one. These sensors measure using the “Time-of-Flight” principle which is ideal for such types of application.

Sensor technology applied

Engagement length control in high performance screwdrivers

Industrial screwing in automated production systems is carried out by automatic screwdrivers. Apart from the torque, the engagement length is the most important criterion for the quality of the screwing operation. Generally, the engagement length, i.e. the screw-in depth, is determined with the aid of a mechanical end-stop or by using a limit switch. Consequently, once set, the engagement length cannot be changed during the production process. The inductive potentiometric displacement sensors in the VIP Series provide decisive advantages in this application. The continuous measurement of the engagement length from 0 to 70 mm enables screwing operations with various depths to be carried out at the same station.

Sensor technology applied

System for testing the risk of creaking with combinations of materials

Ziegler Instruments in Mönchengladbach, Germany develops  and  manufactures  test  systems  that  are  able  to predict the risk of creaking noises due to stick-slip vibrations. In this way, the movement of different material combinations relative to each other - so-called „stick-slip“ - can be examined. For example, a passenger car driving for 100,000km can be simulated in the laboratory in just a few hours.

Sensor technology applied

Coordinate measuring machine

Coordinate measurement machines from Zeiss have been known for decades for the highest quality, precision and reliability. Also the mobile measurement machine, ScanMax fulfills these criteria, in part due to the application of inductive displacement sensors from Micro-Epsilon.

Sensor technology applied

Jib lengths of mobile cranes

The current jib length is important when calculating the torque of the load on the crane. This length is measured with an integrated draw-wire sensor. This simple and telescopic measuring principle makes wire sensors predestined for the task. The sensors can also be retrofitted.

Sensor technology applied

2D/3D measurement station for gaskets

Even if gaskets are just very small components in plant and machinery, they are still critical in terms of their function and operational reliability. However, mechanical engineering companies normally purchase these components rather than produce them in-house. Reliable quality control at goods inwards is therefore essential.

Sensor technology applied

Thickness measurement using displacement sensors

Thickness measurement using displacement sensors is a wide application area. Basically there are distinctions between non-destructive/destructive, non-contact/with contact and one-side/two-sided thickness measurement. The Micro-Epsilon measuring techniques for thickness measurement are all emission-free whereby no emissions regulations of any kind have to be complied with. Thickness measurements must be performed both with contacting as well as with non-contact sensors whereby non-contact measuring techniques show advantages as regards accuracy and measuring speed. There is also a distinction between one-sided and two-sided thickness measurement. Two-sided thickness measurements are carried out with at least one pair of sensors which are installed together on one axis. This pair of sensors measures the target synchronously. The difference between the measurement results (C-A-B) produces the thickness of the measuring object. One-sided thickness measurements must only be performed with non-contact sensors. In doing so, the target is only measured with one sensor and either only a part of the target thickness (e.g. layer thickness) or the complete measuring object thickness is measured. Thickness measurements are mainly used in process control and quality assurance, e.g. for the control of extrusion systems or 100% checking of tube diameters.

Sensor technology applied

Tester for pneumatic actuator

So-called muscles are developed as alternatives to hydraulic cylinders. The hose made of rubber contracts when it is filled with compressed air. An in-house tester has been developed for testing this muscle. A sensor from the optoNCDT 2200 series in this tester monitors the contraction of the muscle.

Sensor technology applied

Automatic test station for heat exchangers

Heat exchangers in plant and machinery serve as heat transfer mechanisms between different material flows. To maximise the heat-emitting area, they are designed using multiple plates. Respectively one connecting flange for the material-conveying cables is welded or soldered onto the last plate. The position and the flatness of the flanges have to fulfil highest requirements so that these can be connected  at  the  desired  point.

Sensor technology applied

Tester for (railway) wheel rim measurement

Testers are integrated in the track bed for the wear control of wheel rims on trains. The profile is checked during the passage of the train. Point-type and line-type lasers measure the diameter and the profile of the wheel. Thus, a precise statement of when the wheel must be reprofiled is possible. The measuring technology thereby is exposed to all weather influences.

Sensor technology applied

Completely automatic 3D repair welding

For heavy equipment such as soft coal excavators, it is often cheaper to repair parts than to replace them. For the repair of chain links during maintenance work, the worn material is welded on again by a robot. In order to automate this process, a 3D surface scan must be performed in advance so that the necessary welding lines can be calculated. The Mabotic company uses laser scanners from Micro-Epsilon for this.

Sensor technology applied

Diameter of a pulley

Diameter and concentricity are crucial factors for a long service life, due to the high rotational speeds achieved by pulleys. These parameters are evaluated on a special test bed, using four optoCONTROL digital micrometres. Two sensors on each level detect the outside diameter of the disc.

Sensor technology applied

Checking the accuracy of robot trajectories

The measurement of the trajectory accuracy or its reproducibility is carried out along a diagonal straight line in space. The robot moves the measuring head, which is fitted with sensors, along a steel rule. The deflection of the 2m long rule due to its own weight is compensated by software. Through the arrangement with six sensors both position and orientation deviations are acquired simultaneously.

Sensor technology applied

Position checking on robots

The introduction of the international standard ISO 9283 demands new non-contacting measurement methods. The measurement system for the position measurement is composed of a measurement cube with a defined weight, a sensor and a support. The sensor is equipped with six U15 eddy current sensors. During the measurement the robot moves the measurement cube into the sensor range. The data from the eddy current sensors is passed via a fast interface to the PC where it is processed. Measurement inaccuracies due to linearity and tilting errors (parallelism between the sensor and measurement object) and thermal effects are additionally compensated in the measurement software.

Sensor technology applied

Draw-wire displacement sensors take measurements in pipe trade

In the piping industry orders are placed for fixed lengths of a certain type of pipe. The available pipes with different lengths are transported from the stores to a measurement table to process the order. Here, pipes are inserted one after the other and the partial lengths summed up using a rugged draw-wire displacement sensor. The movable stop on the table is linked to a sensor wire extension pretensioned by a springdriven motor. The draw-wire extension in the dirty section guarantees a clean wire intake in the sensor and a long service life.

Sensor technology applied

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.

Sensor technology applied

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.

Sensor technology applied

Measurement of key profiles

In the production of security keys, the correct blank must be located in the machine before grinding of the teeth can be checked. An optoNCDT 2200 laser sensor traverses across the profile, recording the surface profile precisely while doing so. A measurement profile without any gaps and a very small measuring spot size are important here.

Sensor technology applied

Measuring the lubricating gap in plain bearings

The lubricating gap of a plain bearing is influenced by several factors such as temperature, speed, angle, load etc. This influence can only be measured under operating conditions.

Therefore, a measurement system which detects the gap size or the shaft displacement is subject to strict requirements: temperature stability, resistance to pressure, oil resistance, small size.

eddyNCDT systems with the miniature sensors U 05 and S 05 have been used successfully for displacement measurements in the crankshaft bearing of internal combustion engines. The special design of these miniature sensors enables them to be inserted in even the smallest of bearings where they deliver reliable, accurate measuring results and high resolution of the values.

Sensor technology applied

Gap detection on glass

Glass substrates are required for certain medical tests. During manufacture of silicon chips, the substrate is milled in a defined grid with a depth of 800µm. For separation, the substrate is broken at pre-defined breaking points in a breaker station. For this, the glass pane must be positioned precisely. An optoNCDT 1700 sensor is used here for gap measurement.

Sensor technology applied

Spindle growth

Spindles of machine tools are subjected to high mechanical load. This load results in thermal expansion of the spindles. The associated change in length causes a certain positioning error for the work to be performed. The SSW sensor is directly integrated in the spindle and measures the thermal expansion there of the tool holder without contact. The miniaturized eddy current sensor can also be used again immediately after a tool change. The measured value is transmitted to the CNC controller as a set offset.

Sensor technology applied

Speed measurement on automatic abrasive cutting machine

Tiles and special bricks are processed according to their type on automatic abrasive cutting machines. The objective is fast throughput times with the best quality result. Here, the setting parameters for the rotational speed, the circumferential speed of the cutting disk and the feed rate of the movable table are important. The table movement is acquired by a rugged draw-wire displacement sensor with incremental encoder. A digital tachometer calculates this speed and displays it.

Sensor technology applied

Eddy current sensors in tribology testers

Eddy current sensors from Micro-Epsilon are used for various measurement tasks in tribology testers of the ITR in Clausthal. They withstand the harshest ambient conditions there as they measure directly on the shaft in the tester. A tester with water lubrication and a tester which examines plain bearings for the automotive industry have already been realized. The position of the test bearing case and the relative movement between the rotor and the test bearing is detected in the tester using eddy current sensors.

Sensor technology applied

Monitoring oil gaps in hydrostatic bearings

Hydrostatic bearings are used in large plant and machinery such as stone mills, telescopic installations etc. Monitoring the gap size is a critical factor, as any disturbances in the hydraulics can cause pressure drops, which in extreme cases, can cause the gap to close, resulting in damage to the bearings and ultimately system failure. Here, it is important to have a system that is easy to install as also ageing plants have to be retrofitted. Due to the long service life and the worldwide use of this plant, the sensor should be easy to replace. For this reason, non-contact eddy current displacement sensors of the eddyNCDT 3001 series are used.

Sensor technology applied

Drive controller in precision respooling machines

Laser distance sensors from Micro-Epsilon are used for the respooling machines of the MEMA company from Menden. They continuously measure the diameter of coils there. Finished coils for the merging of several coils are produced from ring-shaped metal bands in this system. In doing so, the diameter is crucial for the constant band tension.

Sensor technology applied

Underwater Measurement of axial movement and shaft play

The functional safety of systems of special economic importance often depends on the perfect operation of delivery devices (pumps). Increased radial shaftwhirl, or an axial shift due to termal expansion, are first signs of possible malfunctions. Measuring axial movement and shaft play will reduce downtimes of the system and minimise repair costs. For underwater measurement a pressureproof eddy-current position sensor, which has been developed from the standard type U3 with certain adaptations is used. The sensor still has its high basic accuracy, and procuring spare parts is no problem at all. The use of potentiometers with readable setting ensures that the sensor can be easily and quickly adapted to different shaft materials (ferromagnetic or non-ferromagnetic).

Sensor technology applied

Non-contacting roundness measurement for rollers

In the production of tapes and foils the high speeds of up to 2700 m/min that are used today lead to an increased vibration tendency in the roller stands. Even smallest μm-range irregularities in the rolling contour lead to cross-grooves on the rolled material and thus clearly reduce the quality of the product. For quality assurance a highprecision roundness measuring system for rollers is required, in which an eddy-current sensor measures the surface contour of the roller. Ambient conditions like dust or oil must not affect the measurements. With computer support the angular position of roundness errors and the accumulation and periodicity of circularity errors can be documented.

Sensor technology applied

Displacement sensor for nanopositioning tasks

Very small displacements, both static and dynamic, are normally generated by piezo actuators. High precision displacement sensors ensure that these displacements are measured to the required nanometre and sub-nanometre accuracies. Resolution and repeatability of up to 0.04nm are possible. Non-contact, capacitive displacement sensors from Micro-Epsilon provide this sub-nanometre precision. The capaNCDT series combines high precision and the required stability.

Sensor technology applied

Monitoring the clamping of tools

Modern, high performance machine tools are now achieving accuracies of just a few micrometers or even less. Such precision can only be achieved by optimum matching of all components, starting with the drive, then the release unit, tool clamp through to the tool itself. Since most components are permanently installed on the machine, then with correct installation the highest precision can be achieved. The only problem is that the tool is changed with each new phase of the operation and can therefore cause critical deviations.

Sensor technology applied

Machine tool clamping position

An inductive sensor according to the VIP principle is used for displaying the movement of the clamping cylinder in machine tools. The sensor is integrated in the clamping device and determines the axial position of the clamping cylinder. The displacement signal is routed to a control unit which provides programmable switching points. The outputs of the clampCONTROL control unit can be used in a downstream machine or system controller.

Food and beverage

One-sided thickness measurement of container glass

In container glass production, wall thickness and roundness of the bottles are crucial quality features. This is why these parameters must be 100 % inspected. Any faulty containers are immediately rejected and returned to the glass melt. Due to high processing speeds and in order to prevent the bottles from being damaged, a fast, non-contact measurement procedure is required. The confocal chromatic confocalDT 2422 dual-channel measurement system combined with the IFS2406-10 sensor from Micro-Epsilon are ideally suited to this measurement task.

Sensor technology applied

Thickness and volume measurement of potato slices

When producing potato crisps, factors such as consistency, quality and taste depend to a significant degree on the thickness of the potato slices used. Depending on the process parameters and the condition of the tools used, the thickness of the cut slices changes slowly but steadily during the production time. This is why it is important to continuously monitor the thickness during production by using the scanCONTROL 2950-50BL sensor. The sensor projects a laser line onto a conveyor belt, which continuously guides sample slices along it.

Sensor technology applied

Digital 3D measurement of complex parts and shapes

Mabotic devepols and manufactures various designs of digital scanning units. scanCONTROL laser scanner are often used for digitization of parts. The scanner projects a laser line onto the object being measured and records the profile of the line. When the scanner is mounted on a linear axis and the scanner traverses over the measurement target, a 3D image of the target can be generated.

Sensor technology applied

Sorting crabs

Crabs are sorted by size in a sorting system. Thereby, the crabs are transported using a vibrating unit on a roller which has a clearance between 20 mm and 40 mm. For checking the clearance, an induSENSOR series LVP is used which measures the changing clearance and shows it on a digital display. The sensor is designed in stainless steel for the food industry.

Sensor technology applied

Dimensional Testing of Cans for the Food Industry

Accurate dimensions and shape of the prefabricated cans and can-lids is of prime importance, in order to ensure that the lids and the cans match properly and form a permanent airtight seal after the filling and sterilization process. This in order to avoid costly batch sealing failures in the canning industry. A special non-contact automated measurement testing machine was developed to control the dimensional integrity of the cans and the matching lids.

Sensor technology applied

Foodstuffs - temperature measurement

Constant temperature monitoring for the quality assurance is a must for monitoring production processes, foodstuffs storage and the sale of foodstuffs. Non-contact infrared thermometers are particularly used in the areas of storage, transport and manufacturing processes such as baking, freezing, roasting and refining.

Sensor technology applied

Oil film thickness

The oil film thickness for combustion engines describes the gap and thus the quantity of oil between piston and cylinder wall. Thus it is sometimes a determining factor for smooth operation and durability. As the oil film can only be integrated and really measured in the firing condition, it is extremely difficult to manufacture sensors for these environmental conditions and then also find space for them. Specially miniaturized eddy current sensors from Micro-Epsilon are capable for this. The smallest with only 2.4 mm external diameter is integrated directly into the cylinder wall and ground to its shape. There, it measures the distance from sensor to piston or the space available for the engine oil for lubrication in every stroke.

Sensor technology applied

Plastic, rubber

Distance control in 3D printing

Micro laser sintering technology is an additive production technology based on digital 3D design data, whereby a component is constructed layer-by-layer from metal powders using a laser beam. This procedure is also known as industrial 3D printing. The exact positioning of the squeegee to the base surface (distance and tilt angle) requires an exact control method. Four CSE05(01) capacitive displacement sensors are used here. The planarity of the descending construction platform must be inspected before the process starts using three CS02 sensors integrated into an add-on module.

Wear measurement at 8-shaped bore holes in extruder machines

The internal bore hole diameter measuring unit idiamCONTROL 801 detects the wear in the 8-shaped bore holes of extruder machines by measuring the internal diameter. For this purpose a measuring probe is pushed into the bore hole. An integrated capacitive double sensor measures the actual bore hole diameter. In addition the sensor position in the longitudinal axis of the bore hole is measured with a cable-length measuring system.

Sensor technology applied

Non-contact IR temperature measurement of plastic film

Non-contact temperature measurement of thin plastic films is in practice a difficult measurement task. Depending on the type of plastic, the measurement must be performed in different spectral ranges. In research and development of printable films, the surface temperature of heated plastic films is detected using a CTP-7 pyrometer (spectral range 7.9µm). Furthermore, the thermoMETER CTP-3 thermometer with a spectral range of 3.43µm is also suitable for non-contact temperature measurement of plastic films.

Sensor technology applied

Blown film thickness

The thickness of blown films is an important aspect in terms of constant quality in blown film production. Partially strong thickness tolerances can occur for the production in doing so. The blown film system from Micro-Epsilon measures the profile of the film with or without contact directly after the extrusion nozzle. Located on a reversing frame, the system continuously traverses the film tube and provides the data to the host system for controlling the extrusion nozzle.

Sensor technology applied

In-line detection of protective film on PVC window frames

Company „Schüco“ manufactures PVC window frames. The PVC profiles are provided with a protective film after they are extruded. This film protects the frames from scratches and dirt. The colorCONTROL ACS7000 color measurement system checks if the protective film has been applied correctly.

Sensor technology applied

Thickness measurement of black rubber belts

Rubber mats for the structure sealing must exhibit a specified thickness for durability and tear resistance. The thickness of the films is measured directly after the extrusion. The optoNCDT 1700 sensors used measure the distance to the rubber despite bad reflectivity. The thickness is determined from the sensor signal and the distance to a reference roller. The user thus recognizes already starting deviations from the target thickness.

Sensor technology applied

Reading the DOT code on tires

When manufacturing automobiles for the American market, the DOT numbers of the tires must be stored. Vision systems are not suitable for reading the code, due to the poor contrast involved (black letters on a black background). The scanCONTROL 2750-100 measures the distance from the surface with the aid of triangulation. The sensor transmits a height profile of the tire wall directly to the software application.

Sensor technology applied

Extruder bore diameter

The idiamCONTROL system has been developed for checking the wear of extruder bores. The measuring cylinder is inserted in the case bore and pushed as far as the upper end. During retraction of the cylinder, several capacitive sensors measure the case diameter on several tracks. Specially for double worm extruders, the measuring cylinder has two metal pins which run along the saddle of both bores and in this way prevent rotation of the cylinder.

Sensor technology applied

Flat film thickness

The thickness of manufactured films is frequently a decisive quality criteria in production. Specially developed thickness measurement systems are used as early as possible in the production for the check of the thickness. Dual sensors consisting of two sensors with different measuring principles measure the thickness across the complete width of the film from one side without contact. A thickness profile of the flat film is thus produced using which the production systems can be regulated extremely precisely. The dual sensors are compiled differently depending on the type of film.

Sensor technology applied

Non-contacting online layer-thickness measurement of foils

In foil production online process monitoring guarantees constant product quality. MICRO-EPSILON’s KS5 combination sensor measures the layer thickness on foils in a non-contact and thus non-wearing process.

Inline color measurement of plastic injection-moulded parts

In plastic injection moulding, the exact color shade of the products is important, as the color changes during cooling. To date, it has only been possible to measure random samples of cooled pieces. However, the colorCONTROL ACS inline color measurement system from Micro-Epsilon can 100% inspect the products as they are extracted from the mould.

Sensor technology applied

Inline color measurement of transparent film

In non-contact monitoring of continuously produced transparent strips of film, each millimetre of strip produced must be identical in color. As well as color fluctuations, streaks can occur during production. As these films are translucent, the color is measured in transmission using the high speed, high precision colorCONTROL ACS7000 inline color measurement system, which is connected to a transmission sensor head (ACS3) comprising a transmitter unit (TT) and a receiver unit (TR).

Sensor technology applied

Inner liner thickness measurement

Inner liners are used in every tire to prevent the air from escaping. As the inner liner is a characteristic relevant to safety of every tire, there are high requirements for compliance with the target data. An important criterion is the layer thickness. The system for measuring the thickness of inner liners operates without contact and wear-free. The inner liner is routed through the measuring system immediately after the calender roller. A measuring head traverses above the surface. An eddy current sensor measures the distance to the reference roller while an optical micrometer measures the distance to the rubber surface. The system can be integrated in the heating circuit of the calender roller for better temperature compensation.

Sensor technology applied

Thickness Measurement on the Calender

Rubber-coated textile and metal fabrics form the basis of tire manufacture. The rubber is applied to the fabric by calender rolling which demands a uniform layer thickness for the manufacture of high quality tires. The strength and the dimensional conformity of the tire directly depend on the coating process.

Sensor technology applied

Special roll gap measurement on calender press

For continuous, uniform material processing in the field of sealing technology, the gap between the rolls must be set with the hydraulic adjustment device and maintained constant. For this reason the top and bottom rolls are provided with a shoulder and an aluminum ring as measurement objects to the left and right. Using the aluminum ring, errors due to the roll material can be avoided. Two eddy current sensors mounted opposite one another measure the distance to the aluminum ring from a fixed reference point. The roll gap can be found from the sum of the two distances.

Sensor technology applied

Thickness measurement using displacement sensors

Thickness measurement using displacement sensors is a wide application area. Basically there are distinctions between non-destructive/destructive, non-contact/with contact and one-side/two-sided thickness measurement. The Micro-Epsilon measuring techniques for thickness measurement are all emission-free whereby no emissions regulations of any kind have to be complied with. Thickness measurements must be performed both with contacting as well as with non-contact sensors whereby non-contact measuring techniques show advantages as regards accuracy and measuring speed. There is also a distinction between one-sided and two-sided thickness measurement. Two-sided thickness measurements are carried out with at least one pair of sensors which are installed together on one axis. This pair of sensors measures the target synchronously. The difference between the measurement results (C-A-B) produces the thickness of the measuring object. One-sided thickness measurements must only be performed with non-contact sensors. In doing so, the target is only measured with one sensor and either only a part of the target thickness (e.g. layer thickness) or the complete measuring object thickness is measured. Thickness measurements are mainly used in process control and quality assurance, e.g. for the control of extrusion systems or 100% checking of tube diameters.

Sensor technology applied

Thickness measurement of rubber film

Precise thickness specifications are assigned for the manufacture of rubber film which is rolled using calender rollers. Random-sample manual measurements, as previously carried out, are no longer sufficient for today’s demands on quality assurance. Consequently, a system with three fixed tracks has been adapted for in-line inspection of the thickness. For each track an eddy current sensor of Type U6 is built into a jockey follower system which measures against an stainless steel roller. Controllers of the range multiNCDT series 100 are employed for the evaluation electronics. The stainless steel roller represents the reference system for the measurement.

Sensor technology applied

Profile measurement system

In the field of quality assurance, e.g. in the tire industry, profile measurements of the tread and sidewall must be carried out. Sensors or complete profile measurement benches with precision laser and computer systems can be used for this which relay a fully automatic sequence through to the finished output of the required layout.

Sensor technology applied

Softcalender - temperature measurement

Pyrometers from Micro-Epsilon enable the monitoring of fast rotating objects such as, e.g. softcalenders for paper manufacture. The system permanently monitors the fast rotating rolls.

Sensor technology applied

TIM 160 for injection mould applications

Users of injection  mould machines for plastics processing are facing increased quality requirements imposed by end-users, in particular  for  automotive applications. Because of this trend, the importance of online temperature control right after extrusion as a global quality attribute is growing.

Sensor technology applied

TIM 160 for injection mould applications

Users  of  injection  mould  machines  for  plastics  processing are facing increased quality requirements imposed by  end-users,  in  particular  for  automotive  applications. Because of this trend, the importance of online temperature control right after extrusion as a global quality attribute is growing.

Sensor technology applied

Measurement of sprayed skin thickness

Sprayed skins for vehicle instruments and controls and for airbag cladding are sprayed using a robot-guided nozzle. The thickness of the sprayed skin is inspected during the spraying process. An eddy current sensor measures the distance to the nickel-coated spray mould. The eddy current sensor has an opening in the center through which the laser sensor measures the distance to the sprayed part. When subtracted, both signals provide the thickness of the applied sprayed skin.

Sensor technology applied

Hydraulic systems, pneumatics

Filling level

A filling level measurement situation can arise with a liquid substance as well as with dry, bulky goods. The precise measurement of liquid levels is difficult to achieve, nevertheless, the confocal measuring technique is a suitable solution for this problem. Light is also reflected on the surface of liquids and thus provides a reliable result. Filling levels of dry bulk materials are easier to measure due to the surfaces. The ILR Time-of-Flight sensors are suitable for deep containers. Laser sensors from the optoNCDT group are available for shorter sections.

Sensor technology applied

Liquid level

Precisely measuring the level of liquids is known in measuring technology as difficult to achieve. Nevertheless, the confocal measuring technique is suitable as a very good solution for this problem. Light is also reflected on the surface of liquids and thus provides a reliable result.

Sensor technology applied

Piston position in hydraulic valves

In hydraulic drives proportional and servo valves control the volume flow of hydraulic oil. In order that an exact dosage, and therefore a controlled movement is possible, displacement sensors are integrated into the valves. These sensors acquire the position of the control piston to regulate the volume flow. An accurate, non-contact and, above all, dynamic position acquisition is required for this. An inductive displacement sensor from MICROEPSILON best fulfills these requirements.

Sensor technology applied

Dosing systems for high-viscosity glues

In the automotive industry piston dosing systems are used for glueing car windscreens and windows. These dosing systems supply the highviscosity glue to the application gun in an exactly controllable way. The volumetric flow control required for this purpose is achieved by means of a suitable long-stroke sensor in the hydraulic cylinder. The travel signal of the piston is differentiated, and the speed signal deducted from this is supplied to the closed-loop control circuit. The filling volume is determined through the position of the piston.

Sensor technology applied

Lubrication gap

Sliding bearings are used for crankshaft bearings in the engine. A specific minimum distance is required so that the bearing operates as wear-free as possible. Miniature eddy current sensors are integrated in the bearing for this. They measure the distance through the bearing half-shell on the crankshaft. It can thus be established whether sufficient oil is lubricating the shaft in the bearing. If the film of oil breaks down, the distance to the shaft must be almost zero. This is because a certain minimum clearance from the bearing to the shaft is required due to the viscosity of the oil.

Sensor technology applied

Pneumatic slide valve position

Pneumatic control valves are employed in chemical engineering for regulating liquid and gaseous media. In order to achieve a constantly high level of process reliability, the flow rate must be controlled exactly. A slide is driven pneumatically, changing the opening for the flow. An inductive displacement sensor, which measures the slide position, is joined to the slide. A microcontroller handles the control and evaluation of the displacement sensor along with the closed-loop control, parameterization and bus linkage of the control valve. Due to the already existing controller, the position measurement is realized for practically no cost, apart from a few passive components.

Sensor technology applied

Valve

The control piston in a valve controls the oil flow to the hydraulic cylinder. As the piston moves back and forth, drilled holes in the valve body are covered and uncovered. The piston is moved by a linear motor. For this measurement, the sensor induNCDT series LVDT from Micro-Epsilon is used. The sensor is mounted on a pressure pipe located on the valve. In this pressure line a freely moving plunger is guided, which is permanently fixed to the spool. The sensor acquires the plunger through the metal of the pressure line and in this way determines the exact position of the spool. The plunger forms a passive position transmitter having a number of advantages. The measurement occurs without contact and is not subject to pressure, because the sensor is mounted outside of the pressurised region.

Sensor technology applied

Inspection of valve cones

During the automated assembly of cylinder heads, the proper seating of the valve cones is monitored with optoNCDT laser-based triangulation sensors. This prevents valves from dropping into the combustion chamber. The axial adjustment to the relevant measurement position occurs via electric motor.

Sensor technology applied