How TÜV SÜD labs measure the electromagnetic radiation of medical devices, smartphones and TVs

In the high-tech world: Two TÜV SÜD technicians set up equipment in the Straubing test center to test the electromagnetic compatibility of new devices.
Photo: TÜV SÜD

e-mobility on the testing block: The room is fully insulated so no outside emissions disrupt the measuring equipment.
Photo: TÜV SÜD

Lab setup: TÜV SÜD use antennas and test receivers to test electronic devices.
Photo: TÜV SÜD

TÜV SÜD tests electronic devices for their radiation compatibility. Hannes Adelsberger, an electrical engineer and team leader at the EMC Lab at TÜV SÜD in Straubing, explains in an interview how the tests work.

EMC – what lurks behind this abbreviation?

The abbreviation stands for “electromagnetic compatibility.” We test all types of electronic devices in our lab to determine their electromagnetic interference and immunity. However, we do not test their direct effect on the user, but rather how they interact with other devices.

Why is that important? What happens when electronic devices react to each other?

Imagine you’re driving an electric car and pass a pedestrian who is using a cell phone. The radiation given off by the cell phone should under no circumstances cause the car to accelerate uncontrollably, for example. Or consider a patient lying in the intensive care ward hooked up to a life-support system. This should in no way be affected by other medical devices in the room or by the phone in the nurse’s pocket.

How are these tests conducted in the labs at TÜV SÜD?

We place all the devices available on the market on the testing bench. Consumer products, medical apparatuses, automotive components, and even entire vehicles. We measure the radiation that a device gives off as well as the external radiation that it can withstand. And we check whether these measured values comply with the norms and guidelines of Europe, America, or other target markets.

Could you explain to laypeople what equipment you use to determine electromagnetic radiation?

Antennas and test receivers. Our labs look pretty strange. The rooms are ten by 14 meters and have high ceilings. The walls are well-insulated, practically soundproof, so noise and radiation cannot penetrate them. At the same time, the radiation given off by the test device cannot escape either. For us, it is crucial to measure only the device itself and not the lab’s surroundings. After all, radiation from cell phone towers and high-voltage power lines are everywhere in the air, but they cannot be allowed to impact our test results.

Who are generally the customers for this type of testing at TÜV SÜD?

Usually, they are device manufacturers or importers. The industrial sector includes domestic manufacturers in Germany. As to consumer goods, the producers are often from Asia. They want to obtain European market authorizations for their TVs, computers, and smartphones, and need to be certain that they meet local standards and threshold values.

Wouldn’t it be a catastrophe for a manufacturer if TÜV SÜD determined that their new smartphone disrupts every nearby pacemaker?

Companies invest enormous amounts in R&D and every producer takes into account a device’s EMC during the product development phase. Most companies have smaller labs themselves to carry out at least preliminary tests. For that reason, they often bring us the prototypes for us to perform prophylactic tests. After all, if a manufacturer were to build 10,000 televisions and then find out that they cannot get the market authorization, that would be disastrous for the company.

The emissions guy: electrical engineer Hannes Adelsberger, team leader at the Straubing EMV lab.
Photo: TÜV SÜD