Special issue  

Computed tomography (CT) is an important imaging technology which enables minimally invasive procedures. Uncertainties in imaging lead to erroneous initial conditions for the navigation process during minimally invasive surgery and result in a higher risk of unintended injuries. To minimize the risk, the uncertainties of the imaging process need to be estimated and considered during the planning of a procedure. A method for estimating the uncertainty is demonstrated.

We propose a measurement uncertainty model of two complementary optical sensors: a deflectometric and a plenoptic sensor. The deflectometric sensor uses active triangulation and works best on specular surfaces, while the plenoptic sensor uses passive triangulation and works best on textured, diffusely reflecting surfaces. The predicted uncertainties can be used to obtain optimized measurements for varying surface properties. The models are validated exemplarily based on real measurements.

Metrology has a key position in networked, adaptive production, with the task of a holistic and valid assessment of the state of various production scenarios. Current trends and challenges for metrology in networked production, e.g., multi-sensor systems, model-based measurements, virtual measurement processes or the integration into adaptable production systems are described and the concept of sensor information as a service is presented as a key development for the flexible use of metrology.

“Industrie 4.0” or the Industrial Internet of Things (IIoT) describe the current (r)evolution in industrial automation and control. This is fundamentally based on smart sensors, which generate data and allow further functionality from self-monitoring and self-configuration to condition monitoring of complex processes. The paper reviews the development of sensor technology over the last 2 centuries and highlights some of the potential that can be achieved with smart sensors and data analysis.

Test centres supplying accuracy tests for instrument transformers must provide measurement uncertainties for their quality management. In this work, ratio error and phase displacement of instrument transformers are discussed. The traceability to the national standards of PTB, the attainable uncertainty and the permitted error limits of test equipment for testing instrument transformers are presented. An example of an uncertainty budget for a current transformer of the class 0,2 S is given.

In the data sheets of the thermometer manufacturers, different specifications can be found to describe the dynamic properties of contact thermometers. The present paper describes the results of a bilateral comparison made for the first time for determining dynamic parameters for two thermocouples in the laboratories of the JUMO GmbH & Co. KG Fulda company and at the Institute of Process Measurement and Sensor Technology of the TU Ilmenau with similar facilities, but different results.