Comparison of fiber interferometric sensor with a commercial interferometer for a Kibble balance velocity calibration. - In: Measurement science and technology, ISSN 1361-6501, Bd. 34 (2023), 12, 125017, S. 1-10
This article presents a fiber interferometric sensor (FIS) for measuring the velocity amplitude of an oscillatory vibrating object, with a focus on velocity mode measurement in applications using the Kibble balance principle. The sensor uses the range-resolved interferometry method to measure the displacement of the moving object and employs a multi-harmonic sine-fit algorithm to estimate the displacement amplitude and frequency, thereby determining the velocity amplitude. This article provides a comprehensive explanation of the experimental setup and the measurement techniques employed, as well as a detailed analysis of the uncertainty budget, with the performance validation of the FIS benchmarked against a commercial interferometer within a Kibble balance setup. The velocity amplitude of a coil of the Kibble balance, oscillating with an approx. amplitude of 20 μm and a frequency of 0.25 Hz, was measured using the sensor and found to be 31.282 31 μm s^−1 with a relative deviation of −1.9 ppm compared to a commercial interferometer. The high performance of the FIS, especially with regard to non-linearity errors, and the small size of the measuring head enable universality of integration into a wide variety of measurement systems, also including the use as general-purpose vibration and displacement sensor.
https://doi.org/10.1088/1361-6501/acf2b7
Improved peak-to-peak method for cavity length measurement of a Fabry-Perot etalon using a mode-locked femtosecond laser. - In: Optics express, ISSN 1094-4087, Bd. 31 (2023), 16, S. 25797-25814
Differing from the conventional peak-to-peak method using two neighboring spectral peaks in the frequency-domain fringe spectrum of the spectral response of a Fabry-Perot etalon to a femtosecond laser, which contains N spectral peaks equally spaced with a spacing of the etalon free spectral range (FSR), the proposed method employs a pair of spectral peaks with a spacing of an integer multiple k (k ≫ 1) of FSR for measurement of the etalon cavity length d with a reduced measurement error. Under the constrain of the total N spectral peaks obtainable in the finite spectral range of the femtosecond laser, the optimized k is identified to be N/2 in consideration of an averaging operation using N - k samples of d to achieve the minimum measurement error. The feasibility of the proposed method is demonstrated by experimental results with an uncertainty analysis based on "Guides to the Expression of Uncertainty in Measurement".
https://doi.org/10.1364/OE.493507
Improved calibration capabilities for infrared radiation thermometers and thermal imagers in the range from -60 ˚C to 960 ˚C at the Physikalisch-Technische Bundesanstalt. - In: SMSI 2023 Conference - Sensor and Measurement Science International, (2023), S. 398-399
At the Physikalisch-Technische Bundesanstalt (PTB), the national metrology institute of Germany, the calibration facility for thermal imager, infrared calibrators, and radiation thermometers has been up-dated to improve the calibration service. An additional cesium-heatpipe blackbody was installed to close the temperature gap from 270 ˚C to 500 ˚C and a new sodium-heatpipe blackbody was taken into operation. In addition, the precision of the positioning of the devices under test was improved and the new blackbodies were characterized and tested. The calibration facility now marks the state-of-the-art in terms of achievable uncertainties and automatization.
https://doi.org/10.5162/SMSI2023/P61
Fiber-interferometric sensor for velocity measurement in the Planck-Balance. - In: SMSI 2023 Conference - Sensor and Measurement Science International, (2023), S. 127-128
This work describes the use of a compact fiber-interferometric sensor for velocity measurements for the Kibble balance method. Our fiber-interferometric sensor was compared within a Planck-balance setup with a commercial reference interferometer. Results show that the fiber-interferometric sensor is capable of high accuracy velocity measurement comparable with the reference interferometer. High performance and compactness of the sensor head allow it to be integrated into small-size systems, where the use of the conventional interferometer systems is limited or not possible.
https://doi.org/10.5162/SMSI2023/B6.2
A vertically positionable permanent magnet system for the Planck-Balance. - In: SMSI 2023 Conference - Sensor and Measurement Science International, (2023), S. 131-132
The Planck-Balance is a compact version of a Kibble balance, allowing a direct measurement of mass by means of electromagnetic force compensation (EMFC). This means that the effects of deformation have to be considered. The vertical position adjustment of the coil, which is discussed in this article, can reduce many errors, such as errors due to deformations during weighing, which lead to a non-proportional correlation between the current in the compensation coil and the compensated mass. In our setup, these errors can be up to about 8 ppm in the maximum case. In addition, there are other problems such as higher order harmonics in the velocity mode, which can be reduced.
https://doi.org/10.5162/SMSI2023/B6.4
Modelling in measurement - from classical analytical approaches to cognitive data-driven solutions. - In: SMSI 2023 Conference - Sensor and Measurement Science International, (2023), S. 209-210
Models are an inseparable part of Metrology. They make it possible to derive measurement results, including measurement uncertainties, from measurement data or output signals and knowledge about the measurement process. Models establish a functional relationship between the measurand and all relevant quantities on which the measurand depends. Models do not necessarily have to be derived from analytical-functional relationships; they are increasingly data-driven with cognitive capabilities. In general, they are used to design measurement systems, analyze measurement data, make inferences and predictions, and form the basis for evaluating measurement uncertainties.
https://doi.org/10.5162/SMSI2023/D2.3
Current advances in 3D tip- and laser-based nanofabrication in extended working areas. - In: SMSI 2023 Conference - Sensor and Measurement Science International, (2023), S. 245-246
Nanotechnology is affecting almost all areas of life, from semiconductor industry to optics, medicine and agriculture. Classical methods for sensing, measuring and fabricating on the nanoscale are faced with new challenges: features are getting smaller and the variety of structures and materials is increasing. Thus, many new techniques are developed in this field. Research at the Technische Universität Ilmenau aims to support transferring these new technologies to industrial scale for future application. The focus is on tip- and laser-based processes together with devices for nanometer positioning.
https://doi.org/10.5162/SMSI2023/D6.4
Actuator design considerations for the Planck-Balance. - In: SMSI 2023 Conference - Sensor and Measurement Science International, (2023), S. 129-130
The paper presents crucial design considerations for the actuators in a table-top Kibble balance, especially its influence on the uncertainty contribution by the voltage measurements. The resulting contribution is exemplary shown for the PB2 version of the Planck-Balance and constraints are discussed that limit the possibilities to optimize the geometric factor of the measurement actuator.
https://doi.org/10.5162/SMSI2023/B6.3
Characterization of micro spheres through AFM surface scans. - In: Proceedings of the 23rd International Conference of the European Society for Precision Engineering and Nanotechnology, (2023), S. 385-388
Measurement errors in the Planck-Balance caused by alternating forces. - In: Proceedings of the 23rd International Conference of the European Society for Precision Engineering and Nanotechnology, (2023), S. 343-346