Measuring Void Fraction (VF) in a pipeline is crucial for ensuring operational efficiency, safety, and environmental responsibility in various engineering applications. There are several methods commonly used to measure VF in multiphase flow systems. Capacitance sensors are a dependable and...

Artykuł opisuje podstawowe zagadnienia związane z wzorcowaniem multimetrów cyfrowych i ich walidacją. Opisano metody pasma ochronnego stosowanego do walidacji multimetrów jakie są zaimplementowane w oprogramowaniu do automatyzacji procesów wzorcowania FLUKE MET/CAL. Przedstawiono również stanowisko do wzorcowania multimetrów i oprogramowanie. W tekście zamieszczono zestawienie wyników wzorcowania dla różnych metod.

Automation of measurement data acquisition is particularly important when digital instruments do not provide a direct communication interface or when long-term measurements require high repeatability and reduced operator involvement. This paper presents a comparative study of two image-based optical reading methods to acquire indications from a digital multimeter. The reference signal was generated using a Fluke calibrator, while the multimeter display was recorded with an industrial camera. The acquired images were processed independently using two different recognition strategies. The first approach was implemented in the Python environment using a You Only Look Once version 8 small (YOLOv8s) deep learning object detection model trained to classify individual display characters. The second approach was implemented in the Laboratory Virtual Instrument Engineering Workbench (LabVIEW) using a template-based optical character recognition (OCR) method prepared in NI Vision Assistant. Acquisition series were performed for different voltage ranges, with 100 samples acquired for each pipeline and measurement case. All image-acquisition experiments were conducted under controlled laboratory conditions using a fixed camera position, a constant region of interest (ROI), and stable illumination. The detected or recognised characters were reconstructed as numerical values and compared with the reference settings of the calibrator on statistical parameters that describe the dispersion within the series and the deviation of the readings. The study evaluates the practical applicability of both approaches and demonstrates the potential of non-invasive optical reading methods for automated acquisition of indications from measurement instruments.

Theses of reports of the XXII International Scientific and Technical Seminar “Measurement Uncertainty: Scientific, Normative, Applied and Methodical Aspects” (UM-2025), which was held online on December 10-11, 2025. At the seminar, 52 reports by authors from 5 countries were presented: Bulgaria, Italy, Poland, Ukraine, USA. It includes works covering a wide range of topics: development of theoretical foundations of model and empirical approaches to measurement uncertainty evaluation; processing of results and measurement uncertainties evaluation at tests, calibrations, verifications; validation of testing and calibration methods; automation of the process of processing results and evaluation of uncertainty in measurements; improvement of the regulatory base for measurement uncertainty evaluation; organization and conduct of interlaboratory comparative tests and processing of their results; special features of training in measurement uncertainty evaluation. The materials of the seminar are a valuable resource for teachers, employees of testing and calibration laboratories, postgraduate students who seek to expand their knowledge and contribute to the development of measurement uncertainty evaluation. The materials of the collection are published in the author's version without editing.

This article describes the essence of the Minimax method for determining the calibration curve of a measuring instrument. The characteristics of the calibration curve obtained in this way are investigated and compared with the parameters of the curve determined by the least squares method. It was shown that using Minimax provides directly determines the calibration line along with the extreme limits of possible deviations of the experimental data points from this line which regardless of the probability distribution model used certainly encompass all the experimental data points. Therefore, these two lines can serve as an estimate for determining the limits of the maximum permissible error (MPE) of the calibrated measuring instrument. The study was conducted based on the results of the actual calibration of the Fluke 8845 measuring instrument in the ±10 Vdc and 750 Vac ranges at the accredited LABBiKAL laboratory (Rzeszow University of Technology, Rzeszow, Poland).