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

Academic institutes, universities

Experimental tests on a drop impact tester

In the automotive industry manufacturers go to great lengths to improve the passive safety of all vehicles in a collision. The so-called crash absorbers join the fenders with the longitudinal bearers and taken overall they can absorb energy through fixed bumpers and plastic deformation. In addition, attempts are made to reduce the vehicle weight through new designs and the use of new materials. The effect of the actual accident event can be replicated on special drop impact testers. Through the variation of the dropped weight and the height, the impact speed can reach 12.5 m/s (45 km/h). Apart from the force, the deformation is recorded during the collision with a fast triangulation sensor.

Sensor technology applied

Water depth measurement on a river model

With investigations using realiztic models of flowing waters, the river bed must be sampled as accurately as possible and without physical contact. To do this, the laser-based optical displacement measurement system, optoNCDT, is used which features high accuracy with a large measuring range and is largely independent of the ground conditions. It is mounted together with the signal conditioning electronic unit on a measurement carriage movable in the X direction which is suspended from a traversing beam movable in the Y direction. The distance to the water surface is acquired simultaneously with a parallel-mounted ultrasonic displacement system.

Sensor technology applied

Deformation measurement on lightweight structures

Specially designed measurement systems, which record the surface contours without reactive effects on the lightweight structures, are employed for the examination of component deformations under load. To achieve this, two laser-based optical displacement measurement systems can be mounted on a movable subframe subdivided with nineteen fixed reference points.

Sensor technology applied

Measurement of the radial deviation on superconducting magnets

At the Institute for Solids and Materials Research (IWF) Dresden a motor with magnetic bearings has been developed using high temperature superconductors which can be employed for feed pumps for liquid nitrogen. The most important application of superconducting permanent magnets is the superconducting magnetic bearing. For the measurement of the radial deviation of these magnetic bearings, U1 eddy current sensors with special temperature compensation for -196 °C and 20 °C are used in the evacuated and cooled ambient.

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

3D profile measurement of soil samples

German automation company Visutronik GmbH from Neubrandenburg, Germany has developed a laser scanningdevice to measure surface soil samples for subsequent geometric analysis: roughness, surface type expansion (e.g. earthworm courses), etc. The core of the measuring device is the scanCONTROL 2700-100 laser scanner.

Sensor technology applied

Closed-loop gap control in magnetic bearings

Sensor technology applied

High precision measurement of special profile sections in the production line

In the factory research department a fully automatic system for optical geometry measurement has been developed, constructed and integrated into a production line for lift profile rail sections. The system acquires the deviation of±0.2mmfrom straightness in both axes, the length of the section and the thickness of the rail web to ± 0.02 mm in two tracks.

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

Active damping of liquid-cooled centrifuges

At certain configurations of speed, filling level and design parameters, liquid-filled industrial centrifuges tend to produce unstable running characteristics which can lead to failure of the centrifuge. The instability, which arises due to interaction between the fluid and the centrifuge, cannot be rectified by passive means (dampers), so therefore the instability is corrected actively with the aid of a magnetic bearing and suitable closed-loop controllers. The deflection of the rotor, which is acquired with two eddy-current sensors orientated at 90° to one another, is used as input information for the controller.

Sensor technology applied

Household appliances

Load detection in washing machines

With modern washing machines, energy efficiency and environmental protection are becoming increasingly important. In order to achieve optimum results, the load must be measured before the washing starts. This load measurement enables an optimum and maximum load for the machine to be determined, as well as the appropriate dosage of detergent. This reduces operating costs, while also protecting the environment. A direct weight measurement using e.g. load cells is expensive. An indirect measurement of the damper displacement is much more cost effective. Micro-Epsilon offers low cost solutions for displacement measurement in high volume production, namely the magneto-inductive MDS-40-LP-F displacement sensor, which is directly integrated in the damper.

Sensor technology applied

Defect recognition on worktops

Kitchen worktops are now made from a variety of materials, e.g. natural or artificial stone, solid wood and laminate (e.g. HPL). All these materials offer benefits and have special characteristics. However, a defect-free surface finish and perfect edges are critical production factors. The example above is a so-called laminate worktop with a stone decor. As the cutting edge of this top is rough and unclear, it is covered with sidebars. Foreign bodies, uneven distribution of the adhesive or unevenness when closing may produce open joints between the top material and the sidebars. The scanCONTROL 2910-25 laser profile scanner is used to inspect if any open joints are present.

Sensor technology applied

Color detection of kitchen fronts

Kitchens are available in many different colors. In order to guarantee that the customer receives the desired color, the colorSENSOR OT-3-MA-30-16 inspects the color of the kitchen fronts in the painting plant.

Sensor technology applied

Displacement sensor for washing machines

When the washing machine is loaded, the displacement sensor DRA measures how much the outer drum drops. It also measures the drum’s deflection during spin-drying. Due to the inductive measurement principle, the sensor provides absolute position measuring for static and dynamic processes. Operation and the washing result are optimized by the load measurement. The displacement sensor provides an output signal proportional to the weight. This permits full utilization of the drum volume and helps to determine the required amount of detergent.

Sensor technology applied

Washing machine displacement

Using an inductive displacement sensor, the displacement of the suds container during filling and the spinning stage can be calculated. The correct quantity of detergent can be calculated with the data obtained in this way. The speed for the spinning process is adapted in accordance with the displacement. The sensor is integrated in a friction damper using the measurement reducing VIP principle.

Sensor technology applied

Glass, ceramics

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

Display glass defects

A special measuring system has been developed for the quality control of display glass. The glass pane is placed on a measuring table by a robot. A measuring arm with several confocal sensors traverses the glass pane there. If any defects are found, the pane is marked as NOK and rejected. The scanCONTROL laser scanner simultaneously circumnavigates the edges and checks these for defects and dimensions. After the check has been completed successfully, the pane is lifted back into the production process and the next measurement is started.

Sensor technology applied

Display glass / flat glass thickness

A special measuring system has been developed for the quality control of display glass. The glass pane is placed on a measuring table by a robot. A measuring arm with several confocal sensors traverses the glass pane there. If any defects are found, the pane is marked as NOK and rejected. The scanCONTROL laser scanner simultaneously circumnavigates the edges and checks these for defects and dimensions. After the check has been completed successfully, the pane is lifted back into the production process and the next measurement is started.

Sensor technology applied

Planness measurement of display glass

Thinnest glass of outstanding flatness is required for the production of displays for telecommunications equipment. During glass production measuring and monitoring of the flatness is a decisive factor for quality inspection. The results of these measurements can be used for optimizing the pro-duction process. On a high-precision hard rock table in the measuring room samples of these thinnest glass plates are measured by laser-optical triangulation sensors with an accuracy of 5 μm.

Sensor technology applied

Flat glass defects

A special measuring system has been developed for the quality control of flat glass. The glass pane is placed on a measuring table by a robot. A measuring arm with several confocal sensors traverses the glass pane there. If any defects are found, the pane is marked as NOK and rejected. The scanCONTROL laser scanner simultaneously circumnavigates the edges and checks these for defects and dimensions. After the check has been completed successfully, the pane is lifted back into the production process and the next measurement is started.

Sensor technology applied

Flat glass thickness

A special measuring system has been developed for the quality control of display glass. The glass pane is placed on a measuring table by a robot. A measuring arm with several confocal sensors traverses the glass pane there. If any thickness discrepancies are found, the pane is marked as NOK and rejected. The scanCONTROL laser scanner simultaneously circumnavigates the edges and checks these for defects and dimensions. After the check has been completed successfully, the pane is lifted back into the production process and the next measurement is started.

Sensor technology applied

Flat glass - temperature measurement

Temperature plays an important role in the glass industry for many manufacturing and production processes. It is a matter of obtaining precise temperature measurements of transparent (glass) and non-transparent (moulds, crown and side walls of the glass furnace) objects.

Sensor technology applied

Bottle and hollow glass - temperature measurement

Special sensors which are used for permanent temperature monitoring are installed at the individual stations of the glass production line.

Sensor technology applied

Film extrusion - temperature measurement

Infrared temperature sensors from Micro-Epsilon measure the film temperature before the three-roller mill. An optimal regulation of the process temperatures is made possible due to the precise temperature values which results in a constantly high product quality.

Sensor technology applied

Glass machining – temperature measurement

In order to be able to bend and shape flat glass, the exact glass surface temperature must be taken into account. Special pyrometers from Micro-Epsilon have been developed for measuring in glass manufacturing.

Sensor technology applied

Glass thickness

A special measuring system has been developed for the quality control of glass. The glass pane is placed on a measuring table by a robot. A measuring arm with several confocal sensors traverses the glass pane there. If any thickness discrepancies are found, the pane is marked as NOK and rejected. The scanCONTROL laser scanner simultaneously circumnavigates the edges and checks these for defects and dimensions. After the check has been completed successfully, the pane is lifted back into the production process and the next measurement is started.

Sensor technology applied

Thickness measurement of glass

The specification of the thickness of glass panes is an optimization process between a required mechanical strength and efficient use of materials. In the manufacturing process the glass thickness is measured and the conformance to prescribed tolerances is monitored. The measurement is carried out with displacement sensors working on the eddy-current principle. Here, the sensor hovers over the glass surface and measures through the glass to a metal plate situated behind it. The values can be read off directly on the device; an analog output voltage facilitates further evaluation.

Sensor technology applied

Glass industry / glass - temperature measurement

Temperature plays an important role in the glass industry for many manufacturing and production processes. It is a matter of obtaining precise temperature measurements of transparent (glass) and non-transparent (moulds, crown and side walls of the glass furnace) objects.

Sensor technology applied

Glass drop measurement - temperature measurement

The use of non-contact temperature measurement equipment is required for measuring the glass drop temperature. Pyrometers from Micro-Epsilon are particularly suitable due to the fast operating processes.

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

Measuring glass cups

In the production of drinking glasses, the stem and cup are connected using a gas burner. In order to enable the precise connection of the glass stem and cup, the distance between stem and cup needs to be measured. Monitoring this gap size allows for feed rate control during production. An optoCONTROL optical micrometer measures this gap.

Sensor technology applied

Glass pretensioning - temperature measurement

CTlaserGLASS has been specially developed for applications in the glass processing industry, in particular for glass bending, forming and hardening processes. The non-contact thermometer ensures precise monitoring of the temperatures.

Sensor technology applied

Windscreen defects

During the production of windscreens, it can happen that the correct curvature of the windscreen has not been maintained or the fissures and cracks in the surface make the windscreen unusable. A system has been developed for this purpose which inspects the windscreens completely in-line for a surface free from defects. Several confocal sensors on a measuring beam measure the distance to the surface. Using the automatic centering function of the confocal sensors, they track the curvature of the surface precisely. The high resolution makes it possible to inspect the windscreen for cracks and fissures at the same time.

Windscreen thickness

Using a film between several glass panes, laminated safety glass prevents dangerous shards flying around in the case of breakage. The adhesive film is clamped during the production. In doing so, it is important that the film shows the correct thickness in order to be able to ensure the required safety. Thickness can be measured on one side using the optoNCDT2401 confocal system. The light from the sensor penetrates the glass and displays the thickness of the film in the pane.

Sensor technology applied

Windscreen profile

Flat glass for demanding industrial tasks is subjected to 100% testing after the production. Dimensional accuracy is important for industrial glass which is used for demanding technical tasks. Examples of such types of glass would be windscreens, display glass for LCD televisions or glass for the production of photovoltaic modules. Even a small deviation from the required geometry or thickness can drastically influence the later function of the glass. The glass profile measuring system uses confocal sensors. These operate with white light and precisely measure the profile of the pane and also an inner layer. A laser scanner is also used for determining the measurement.

Sensor technology applied

Windscreen gap

The final appearance of a product plays a crucial role everywhere that panes are positioned automatically. Apart from the shape, stability, color etc., the final appearance is also dependent on the position of the glass in the frame. The pane must be inserted in as centerd a position as possible. A laser scanner also detects automatically for the insertion of the glass whether the gap is the same on all sides or not. If differences occur, the pane can still be moved somewhat. The extremely difficult conditions of the different reflection factors of glass and frame (metal, wood, plastic) do not affect the quality of the measured data.

Sensor technology applied