The Mobility Transition Begins in Manufacturing

Sustainable mobility doesn’t begin on the road—it starts in the manufacturing process. Electric motors, connectors, fuel injection systems, fuel cells, and battery cells can only operate efficiently and safely over the long term if their relevant geometries are rigidly controlled. Every deviation detected early on prevents scrap, rework, and unsafe process conditions. Metrology thus makes a direct contribution to resource conservation, long service life, and reliable operation. This article uses five applications to demonstrate how coordinate measuring machines from Werth Messtechnik—using optics, probes, computed tomography, and multi-sensor systems—combine short measurement times, high resolution, high accuracy, and system availability.

Four Requirements, One Common Sample

Thin electrical steel sheets, delicate contacts, internal nozzle geometries, large-area embossed plates, and safety-critical cells differ significantly in terms of material, geometry, and production volume. Nevertheless, the requirements for metrology follow a common pattern. Short measurement times ensure throughput in series production; high resolution makes fine structures and incipient defects visible; high accuracy maintains the usable manufacturing tolerance; and available systems prevent downtime close to production. For accuracy, the rule of thumb known from test process suitability applies: the measurement uncertainty should be 10 times smaller than the tolerance. The greater the measurement uncertainty, the narrower the usable manufacturing tolerance becomes, and the more workpieces that are close to the limits must be discarded as a precautionary measure according to the decision rules of ISO 14253-1. More accurate measuring machines, on the other hand, preserve the manufacturing tolerance because the tolerance band remains available to the manufacturing machines and is not eroded by metrology. They thus reduce scrap and inspection costs, even if they are more expensive to purchase. However, the greatest cost savings come from rigid, controlled processes. Those who identify trends before workpieces fall outside the tolerance range reduce scrap and rework at the source.

Rotor and Stator Laminates for Electric Motors

High production volumes for rotor and stator laminations involve delicate, thin workpieces. An electrical lamination for traction motors is typically only 0.2 mm to 0.35 mm thick, and the trend toward thinner laminations reduces eddy current losses and increases efficiency. Burrs on the punched edges are more than just a cosmetic issue. They can penetrate the insulation coating of adjacent laminations and cause layer short circuits, leading to overheating and a loss of efficiency. At the same time, burr formation is an early indicator of die wear. Monitoring trends in burr formation allows for condition-based maintenance of tools rather than maintenance carried out according to intervals. Many recurring geometries must be tested in a short amount of time, and because probing forces can cause deformation of the thin sheets, webs, burrs, flatness, and warpage must be captured non-contact and at high resolution. The ScopeCheck® FB DZ coordinate measuring machine from Werth Messtechnik is designed for this type of production inspection using HD raster scanning. During raster scanning, the image-processing sensor captures the workpiece during axis movement in many overlapping single images, which are combined into an overall image with up to 20,000 megapixels. This method is available across the range, from the highly accurate VideoCheck® series to the production-oriented ScopeCheck® machines. This allows the entire sheet metal part to be captured without re-clamping, and process fluctuations become visible early on, before they cause scrap or unstable downstream processes.

Connectors and Fine Pin Geometries

Connectors represent a typical inspection task in the field of electrification. With 800-V vehicle electrical systems, charging infrastructure, and growing sensors, the number of contacts per vehicle is increasing, as are the demands placed on each individual contact. Deviations in pin position increase insertion forces and contact resistance, which can lead to excessive heating in high-voltage connectors and, in the case of signal contacts, to failures in driver-assistance and charging functions. Structural resolutions of 20 µm or better are required for the fine pin geometries. Raster scanning HD captures large workpieces with many features in seconds and is 50 times faster than conventional image processing. Many contacts are also overmolded or, once assembled, no longer accessible from the outside. Here, Werth’s computed tomography provides a non-destructive view of the entire workpiece volume. To do this, the workpiece is X-rayed from multiple orientations on a rotary table, and the software reconstructs a three-dimensional volume model with all external and internal geometries from the projections. Werth TomoScope® machines measure 10 times faster than comparable CT systems. The WinWerth® software visualizes results such as pin positions or installation orientations in a way that makes them directly usable for process control.

Injection Nozzles for Gasoline, Diesel, and Hydrogen

Injection nozzles remain relevant for various propulsion concepts, ranging from optimized internal combustion engines to hydrogen propulsion. The critical features are often found on the inside. The orifice diameters of modern injectors are often only 100 µm to 200 µm, and the shape and edge rounding of the bores determine the spray pattern, fuel consumption, and emissions—factors that are becoming increasingly important as exhaust emission standards become stricter. In hydrogen propulsion, leak tightness and new material pairings come into play because, unlike liquid fuels, the dry gas does not lubricate. Burrs and tolerances in the range of a few micrometers determine flow rate and long-term durability. A purely external inspection is not sufficient for this. Werth’s computed tomography captures external and internal geometries—such as blind holes and needle seats—non-destructively and comprehensively. Burrs are not only detected but also measured and objectively evaluated. For particularly small, highly accurate tactile measurement tasks—including Roughness—the Werth Fiber Probe® WFP rounds out the product range. Established for about 30 years, this micro-probe with a 20 µm ball operates with low probing forces and reaches features that are virtually inaccessible to conventional styluses.

Bipolar plates for fuel cells

Fuel cells directly convert hydrogen and oxygen into electrical energy, with water as the sole reaction product. Bipolar plates are key functional components in this process. They separate the individual cells of the stack from one another, distribute the gases evenly across the active surface via fine channel structures, conduct the electric current from cell to cell, and dissipate the heat of reaction through cooling ducts. For metrology, this means inspecting the entire surface of large, finely structured workpieces. Metallic bipolar plates are stamped or hydroformed from foils, some of which are less than 0.1 mm thick. The channel structures are measured to have a few hundred micrometers in length. Because a stack consists of several hundred plates, flatness and thickness deviations accumulate across the stack and affect contact pressure, contact resistance, and hydrogen tightness. Embossing depths, sealing surfaces, and tool misalignment also have a direct impact on function and reliability. At the same time, the measurement must not mechanically affect the sensitive surfaces. Werth multi-sensor systems combine fast optical methods with non-contact distance sensors for this purpose. Raster Scanning HD tests the large plate surfaces in a short amount of time, and the highly accurate Werth CFP (Chromatic Focus Point) chromatic distance sensor measures embossing depths, flatness, and warpage without causing any mechanical interference. With the continuously adjustable WRT rotary/tilt head, it can be aligned perpendicular to inclined surfaces. This helps accelerate series production approvals, reduce scrap rates, and gather process data for mold corrections and rigid production windows—especially during the series ramp-up phase, when stamping dies are corrected iteratively.

Battery Cells and 100% Inspection

The most demanding requirements are found in battery cells. Terminals, overhangs, jelly-roll geometry, delaminations, and particles must be tested in seconds and at high resolution. The anode overhang is a safety-critical size in this context. If the anode does not reliably protrude beyond the cathode, there is a risk of lithium plating, leading to capacity loss and the danger of a short circuit. Metallic particles and delaminations inside the cell can trigger internal short circuits, potentially resulting in thermal runaway. According to assembly, computed tomography is the only method that non-destructively visualizes and performs measurement of such internal features. This makes 100% inspection a central focus of manufacturing. Werth TomoScope® systems, equipped with a Werth HighResLonglife X-ray source and AI-supported automatic defect detection, are designed to address this challenge. They detect defects as small as a few micrometers—up to 35 times faster and in a quarter of the footprint of solutions with comparable levels of comparability. The high-resolution Werth X-ray sources, ranging from 130 kV to 230 kV, enable measurements 5 times faster than conventional reflection sources while maintaining the same resolution. Their 12-month maintenance cycle aligns with regular equipment maintenance. The parallel operation of two machines in a single test station cuts cycle time in half—for example, from 30 seconds to 15 seconds—while also providing redundancy for maintenance and in the event of malfunctions. Regulatory support is also provided by the EU Battery Regulation (EU 2023/1542), which requires complete documentation and traceability through the battery passport and CO2 footprint declaration.

Traceable Measurement, Capable Testing

Across all applications, the automotive industry requires IATF 16949-compliant, verifiably suitable testing processes, the suitability of which is typically assessed according to VDA Volume 5. Coordinate measuring machines with computed tomography are specified and accepted according to VDI 2617 Part 13 and ISO 10360 Part 11. In addition, Werth offers CT coordinate measuring machines calibrated according to the specifications of the German Accreditation Body (DAkkS), which has been mandatory in the automotive industry for several years. Traceable measurement throughout the entire workpiece volume is thus based on the same standards as traditional tactile and optical coordinate metrology.

Mastered Processes as a Shared Benefit

The examples show that sustainable mobility does not require an individual measurement technology, but rather the right combination of sensors, speed, evaluation, and availability. Optics, stylus, computed tomography, and multi-sensor systems complement one another when external contours, internal geometries, micro-structures, and sensitive surfaces need to be evaluated close to the production line. For manufacturing managers, however, precision in the laboratory is not the only factor that matters. What matters most are reliable approvals, reduced scrap rates, available systems, and measured data that directly contribute to process control. Metrology thus becomes a building block of economical, safe, and resource-efficient manufacturing—and thereby a cornerstone of the mobility transformation.