Autor: Annett Boblenz

Responsible Construction

16.02.2022 Environment Kommentare geschlossen

More than half the buildings that will exist in 2060 haven’t even been built yet. That’s precisely why sustainable construction is already necessary today. A few examples show that many things are feasible these days.

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DEKRA Award: Scoring Points with Safety

09.02.2022 Special Kommentare geschlossen

The DEKRA Award 2021 was bestowed on four organizations for their top achievements in the name of safety. In the “Startups” category, the young Swiss company Lakera makes artificial intelligence (AI) safer.

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Supply Bottlenecks threaten Global Trade

05.01.2022 Connectivity, Special Kommentare geschlossen

Leere Supermarktregale in Großbritannien, europaweite Lieferengpässe von Kühlschränken bis zu Notebooks und PC-Komponenten, Lieferzeiten bei Neuwagen deutscher Premiumhersteller oder individuell gefertigten Fahrrädern von 10 bis 18 Monaten – der globale Warenhandel stockt gewaltig. Dafür gibt es viele Gründe.

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Qualify Staff for Vacancies

22.12.2021 Special Kommentare geschlossen

REWE, Germany’s second-largest food retailer, works together with DEKRA Akademie to qualify people from different nations for the retail and logistics sectors.

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Artificial Intelligence: Smart and Self-learning

10.11.2021 Cybersecurity, Digitalization Kommentare geschlossen

Artificial intelligence does amazing things in many different areas – from quality control in manufacturing to diagnosing skin cancer. Testing and certification is an absolute prerequisite for low-risk operation of relevant systems. And a company like DEKRA plays a key role.

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Buying Used Cars: Digitization is Catching on

20.10.2021 Digitalization Kommentare geschlossen

Buyers and potential buyers increasingly use online tools in their research. This was the result of a survey by DEKRA and Ipsos in Germany, China, the USA and France.

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Acoustic Cameras: Noise Detectives in Action

13.10.2021 Innovation, Special Kommentare geschlossen

Occupational safety, building acoustics, industry: When noise becomes a problem and conventional analysis methods fail, acoustic cameras can help. The cases are as diverse as life itself.

An acoustic camera can be used to visualize sources of noise. Photo: Shutterstock/ElRoi ; Illustration: ETM

It’s impossible to switch off your ears. At most, you can try to ignore unwanted sounds. A whisper is as quiet as the light rustling of leaves in the wind. A bottle tossed into the bottle bank is as loud as a gasoline lawnmower – except it’s over much faster. And whether we’re dancing at a club or disco or standing next to a chainsaw, both are similarly loud and can permanently damage our ears. But the perception is different: One is considered music, the other is noise. The concept of noise is therefore very subjective, but the fact that noise can make people ill is a matter of scientific knowledge. A person’s body and psyche suffer when permanently exposed to noise.

For this reason, legal regulations apply in various countries to protect the population from damage to their health. In Germany, the Technical Instruction on Noise Abatement (TA Lärm) regulates the protection of the general public from industrial noise, while the Occupational Health and Safety Ordinance (Arbeitsschutzverordnung) takes effect in professional life. In addition, “International Noise Awareness Day” intends to raise awareness of the issue. In Germany, it has been held as the “Day Against Noise” since 1998.

Searching for the sound source with the acoustic camera

For Ilja Richter, every day is a “day against noise”. He’s an expert for noise immissions at DEKRA and uses an acoustic camera to track down the causes of noise. “With the usual noise measuring devices, you can only record the sum of sound sources at a certain location. You know how loud it is, but not necessarily what the relevant sources are,” explains Richter. “The acoustic camera, on the other hand, makes the sources visible in images.” It uses an array of three plates, each with 128 microphones, to capture noise, which is then color-coded and superimposed on the optical image: particularly loud areas are red while quieter ones are blue. This is reminiscent of a thermal imaging camera that can detect thermal bridges on house facades.

DEKRA expert Ilja Richter usually comes with large luggage. Photo: Kai Joachim

“We’ve been using the camera for two years,” says Richter, who’s had a wide variety of measurement tasks. For example, there was a hotel in northern Germany, a new building. No matter how hard the staff tried, they received heavy criticism on online review portals. “The rooms were so badly soundproofed, it was as if there were no walls at all,” Richter recalls. “Whether the residents were watching TV or frolicking in bed, the room neighbors overheard more than they would have liked.” Richter’s measurements revealed several acoustic bridges, through which the noise spread into neighboring rooms.

The walls were of lightweight construction and the TV sets of two rooms always hung back to back on the same wall. The outlets for the connections were also at the same height. “This meant that low-frequency sounds were easily transmitted from one room to the other,” Richter explains. But it wasn’t just low-frequency sounds that penetrated to the neighbors. “The transition of the wall to the concrete ceiling via a shadow gap was also incorrectly executed,” says the expert, “so high-pitched sounds could spread.” After this report, the hotel finally had the means to force improvements.

Expert opinions to enforce further improvements

But sleep can be robbed not only in a hotel, but also on one’s own property. “A resident whose house was 300 meters away from a cement plant in southern Germany kept complaining about noise at night,” Richter says. During the day, the plant was proven to comply with TA Lärm, but not always at night. “A cement plant like this consists of countless installations, some of which are indoors, some outdoors. In addition, there are chimneys, towers – many potential causes,” he explains. Richter’s acoustic camera was predestined for this case.

Ilja Richter knows how to track down noise sources. Photo: Kai Joachim

However, vegetation obscured the direct view of the cement plant, which was 80 meters lower than the house. The camera needs a clear view for the image. The problem was solved with a lifting platform that lifted the camera 30 meters into the air to see the cement plant. “The acoustic image showed that the main sources were two buildings in the plant,” Richter says. “But it was impossible to determine more precisely from that distance, so I had to take acoustic images on the plant grounds as well.” That cleared things up: The bricks used in the building facades only insulated against heat, not sound. In addition, a lot of noise was escaping between a roll-up door and the facade because the space was poorly insulated. “To arrive at this result with a conventional sound meter, measurement and evaluation would have been much more tedious and would therefore have cost at least four times more,” says Richter.

Another “noise case”: The workforce of a sheet metal processing company in Lower Saxony was exposed to extreme noise. More precisely, to a shrill whistling sound in a huge hall. It was Richter’s job to find out which machine was the source and what was causing it. “The source turned out to be a machine for cutting sheet metal,” he says. A massive machine: it cut sheet metal that was unwound from one-meter wide and two-meter thick rolls. To make the cut, it used vacuum to suck the uncoiled sheet metal onto a rotating drum. “With detailed camera footage and the machine manufacturer’s design drawing, I was ultimately able to identify parts of the axle suspension as the source of the noise,” Richter says. “Air turbulence at a specific location inside the drum was causing the shrill whistle.” The company called in the machine’s manufacturer to remedy the problem together. And Ilja Richter was able to turn his attention to new cases.

Elevators: Technical Showcase

25.08.2021 Special Kommentare geschlossen

Elevators make life easier, sometimes even more impressive or oppressive. But there’s one thing they all need to be: safe.

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Travel: We’re Taking to the Skies Again

11.08.2021 Mobility, Special Kommentare geschlossen

Normality is still a long way off in the aviation sector. But demand for national and international connections is on the rise. Passengers have to keep a few things in mind.

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Automated Driving: Between Wish and Reality

28.07.2021 Autonomous Driving, Mobility Kommentare geschlossen

Behind the scenes, car manufacturers and suppliers are hard at work on algorithms for fully automated driving functions. However, only elaborate test programs can clarify how vehicles will behave when using said functions. The experts at the Lausitzring racetrack’s DEKRA Technology Center know all about the latest developments. We asked about the current state of the technology.

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Sustainability: Soccer Sets an Example

21.07.2021 Special Kommentare geschlossen

More and more sports clubs are focusing on holistic sustainability and looking at economic as well as social and ecological issues. The sustainClub is a recognized sustainability standard that provides orientation in professional soccer. Six clubs can boast this award from DEKRA.

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Cargo Ships – Giants of the Sea

14.07.2021 Mobility Kommentare geschlossen

Their size is measured in soccer fields, their carrying capacity commonly approaches 200,000 metric tons – it’s a constant head-to-head race to the top in the rankings of the world’s biggest container ships. We take a closer look at the largest cargo giants currently in service.

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