The SURAGUS GmbH is a young innovative and fast developing German company, a spin-off from the Fraunhofer Institute for Non-Destructive Testing Dresden. The company develops, manufactures and sells eddy current-based testing technology for contactless in-and off-line determination of sheet resistance, thickness and conductivity of functional thin-films on glass and foils, wafer, carbon fiber composites, metal layers, TCOs, CNTs, and nanowires. Furthermore, it offers high spatial resolved conductivity mapping devices for defect analysis and quality assurance of simple and complex layer systems. The applied powerful electronics offers a wide frequency range from 10 kHz to 100MHz in order to achieve different sensitivities and penetration depth depending on the application. SURAGUS has implemented the process-oriented quality management system according to international standard DIN EN ISO 9001:2008.

Company details

Maria-Reiche-Str. 1 , Dresden , Sachsen 01109 Germany

Locations Served

Business Type:
Industry Type:
Monitoring and Testing
Market Focus:
Globally (various continents)


The eddy current method utilizes local conductivity variations of the test objects for the characterization of correlated quality characteristics such as thickness, conductivity, homogeneity and purity or physical changes. The complex eddy current signal contains various information about the test object which can be separated in many cases with simple or complex algorithms. Our eddy current testing technology is based on a powerful eddy current electronics with a frequency range from 10 kHz to 100 MHz, which is combined with different sensor concepts depending on the application.
Primary advantages:

  • Contact-free
  • Fast (EddyCus Systems measure at a rate of 50.000 measurements per second)
  • Suitable for automation
  • Broad porfolio of sensors for different applications

Quality Management

We develop innovative products and deliver standard and customized solutions. In order to meet the required quality demands, a process-oriented quality management system is applied.


  • Contactless Conductivity measurement of functional thin films (e.g. TCOs, CNTs, Metallization, Silver-Nanowire)
  • Non-contact Orientation testing and flaw detection for Carbon fiber composites (undulations, Impacts, gases, thrust faults)
  • Contactless weight determination in many carbon fiber materials
  • Determination of gradients of super-alloys
  • Layer thickness measurement of thin films and coatings from 5 nm thickness
  • Mapping for errors in conductive layer system (cracks, voids, delaminations, etc.)

Who we are

SURAGUS GmbH is a German company that is specialized in providing solutions for nondestructive material testing. We use new technical opportunities and the technical advances in microelectronics, manufacturing and miniaturization technologies and computer technology to develop eddy current testing solutions optimized for our customers’ needs.

The applied eddy current testing technology features a wide frequency range that comprises also very high frequencies. This flexibility in range combined with advanced measuring procedures allows the fast testing of both very low and well conductive materials.

Our testing equipment portfolio comprises portable hand-held devices, table-sized benchtop testing solutions, robot based systems and standard and customized inline-solutions.

Where we come from

SURAGUS is a spin-off of the Fraunhofer-Society, one of the largest German research organizations. Some members of our team have been working at the research group of Prof. Henning Heuer at Fraunhofer IKTS Dresden (Germany), who has been an important mentor during the founding process.

Since then the company has been growing continuously and now consists of an interdisciplinary team of mechanical and electrical engineers, of mathematicians and physicists and of programmers and business administration specialists.

What is important to us

Our solutions contribute to a sustainable use of resources in various industries. Our solutions for process control and quality assurance support efficient production processes with highest product qualities at high throughput and low scrap rates. Moreover, it is important to us that we offer an inspiring, professional work environment to our staff, which provides freedom for self-actualization as well as security and flexibility for our families.

What to expect from us

  • Strong commitment to our customers and business partners.
  • High innovation capacity and desire for new innovations (recognized with national and international innovation awards e.g. JEC AWARD and Innovation Award of Saxony).
  • High technological affinity due our very technology enthusiastic and up-to-date development team.
  • High flexibility to cater customer needs supported by fast internal decision making processes and strong team spirt.
  • Strong networking with industrial and institutional global research landscape.
  • Strong customer focus and short response times by our project managers.
  • System provider of comprehensive individually customized solutions incl. integration of additional metrology (OEM) and customized software and hardware.
  • Social involvement in the training of young people and participation as a knowledge provider as German “hidden Champion” and consultant to workshops (for example, at the workshop 'Strategies for Promoting Hidden Champions' with the Korean Prime Minister, the Fraunhofer President and the Saxon Prime Minister in 2014).

What we vouch for

  • Quality: All of our processes are certified according to DIN EN ISO 9001:2008 and are continuously monitored and enhanced.
  • Service: Customer satisfaction is decisive for our work. Therefore our project and service engineers support our customers from the first contact to after sales services.

What we offer

  • Consulting on tackling testing tasks - our experts discuss your testing tasks and propose according testing solutions.
  • Providing of standard solutions.
  • Providing highly individualized testing solutions - we adapt our proven metrology systems to meet your needs
  • Short response times.
  • Local contact persons and communication in many languages - worldwide network of sales and service partners, presence at important trade fairs and conferences.


  • Deutsch

Quality Assurance using Eddy Current Testing

The eddy current testing method utilizes local conductivity variations for the characterization of quality characteristics such as thickness, sheet resistance, material homogeneity or other physical changes in the sample of investigation The complex eddy current signal contains various information about the test material, which can be separated in many cases with simple or complex algorithms. The applied powerful eddy current electronics offers a wide frequency range from 10 kHz to 100MHz that is utilized to achieve different sensitivities and penetration depth depending on the application. All SURAGUS products are offered with an user-friendly software for fast real-time evaluation.

Principle of Eddy Current Testing

The eddy current testing method is a nondestructive evaluation method. It is widely used for crack detection as cracks cause very large local conductivity changes. However, there are many other applications in which highly sensitive and spatially resolved conductivity analysis can help to solve various inspection tasks. The basic principle is shown below.

  • An applied alternating current to a coil creates a primary magnetic field
  • Provided that there is a conductive sample in this changing field, eddy currents are induced following the law of induction.
  • The eddy currents generate a second magnetic field. This secondary field is opposed towards the primary field (c.f. Lenz's law).
  • The properties of sample change the resulting field that can be characterized in various ways, for example, with a pickup coil.
  • The impedance change provides information about capacitive and resistive properties of the sample.


  • Contactless and nondestructive
  • extremely fast (we utilize up to 50,000 samples per second)
  • good automation abilities
  • high sensitivity

Method variations

  • Impedance - Spectroskopy (cf. Fraunhofer IZFP Dresden)
  • Muli-frequency eddy current testing
  • Impuls eddy current
  • Frequenzsweeping analysis

Skin effect

Eddy currents concentrate near the surface close to an induction coil and their strength decreases with distance from the coil. The EC density is being largest near the surface of the conductor, decreasing exponentially at greater depths. This decay is known as the term, Skin effect. The skin effect occurs when induced Eddy Currents at the surface generate an opposed magnetic field that lowers the entire resulting field, thus causing a decrease in current flow as the depth increases.

Standard penetration depth

The depth that eddy currents penetrate into a material is affected by the frequency of the alternating current, the electrical conductivity and magnetic permeability of the sample. The depth of penetration decreases with increasing frequency and increasing conductivity and magnetic permeability. The depth at which eddy current density has decreased to 1/e, or about 37% of the surface density, is called the standard depth of penetration (d or 1d)and used as criteria of ideal measurement. At three standard depth of penetration (3d), the Eddy Current density is down to only 5% of the surface density. So, defects or variation deeper than the three standard depth of penetration cannot be recognized because the EC density in this depth is too low to detect. Thus, achieving the standard penetration depth is the most important factor at Eddy Current testing and this is realized by selecting appropriate frequency suitable for a material property.

EC Density

Since the sensitivity of Eddy Current inspection depends on the Eddy Current density at the defect location, it is important to know the strength of the Eddy Currents at this location. When detect flaws, a frequency is often selected which places the expected flaw depth within one standard depth of penetration. This assures that the strength of the Eddy Currents would be sufficient to produce a flaw indication.