Domen Hudoklin

Simultaneous calibration of a large number of thermocouples

The objective of this paper is to analyze major error sources in the process of simultaneous calibration of a large number of thermocouples (TCs). The main reason for the occurrence of additional error sources when a large number of TCs are simultaneously calibrated is due to additional inhomogeneity effects and characteristics of a particular measuring setup. The need for such calibrations is due to the fact that, often, a large number of relatively low-cost but traceably calibrated TCs are needed for monitoring purposes and measurements of temperature profiles in applications, such as evaluation of temperature and humidity chambers, wind channels, tunnel furnaces in steel plants, etc. The fact is that the overall uncertainty attributed to each particular TC during simultaneous calibration exceeds the uncertainty assigned to a TC during a calibration process of a single TC. Nevertheless, in most cases, the proposed solution is highly acceptable, especially in the area of testing, due to a significant decrease of calibration costs yet still meeting testing requirements.

Automated system for evaluation of climatic chambers

In this paper an automated system for the evaluation of climatic chambers is presented. Besides automation, a basic emphasis is given to the reliability of operation, flexibility and the possibility of achieving a minimal uncertainty for the given application. The system is developed to completely satisfy all standards and requirements concerning evaluation and/or calibration of climatic chambers in the laboratory as well as on site.

On-Site Environmental Conditions—Do They Really Affect the Measuring Accuracy?

According to requirements of the ISO/IEC 17025:2005 standard, environmental conditions while calibrating are monitored and stated in the calibration certificate. In this paper we present an experiment for evaluation of the behavior of our on-site measuring equipment regarding its specifications and the suitability of these specifications for our typical on-site work. We built a measuring setup for determining the temperature and relative humidity dependence of our on-site equipment. Main units of the equipment were placed in a climatic chamber, while temperature sensors and humidity sensors were placed into an ice bath and humidity generator, respectively. The temperature and relative humidity conditions in the climatic chamber were changed incrementally from 5°C to 45° and from 80 % to 20 %. Results are presented and evaluated. The built measuring setup was proven to be a useful tool for determining the temperature and relative humidity dependence of our on-site equipment. By observing the dynamic transitions of the instrumentation between changes of conditions possible dynamic effects could be evaluated also.

Custom made automated system for determination of humidity and temperature gradients in climatic chambers

Absfrocl -The objective OJ lhis paper is to present method for determination of humidity and temperature gradients in climntic chambers, independent OJ the size of the chamber. In the paper custom made automated system is discussed as well. The system is developed to satisfi all the requirements concerning determination of humidity and temperature gradients in climatic chambers. Data acquired with this sysfem can be afierwards used for calibration cerfii/icate OJ the climatic chamber itser or as a basis for the uncertainty contribution oJthe climatic chamber in the process of calibration OJ the relative humidity sensors inside the chamber. The system itself can be used under the laboratory conditions, as well as forthe calibration on-site.

Design and Clinical Evaluation of a Non-Contact Heart Rate Variability Measuring Device

The object of the proposed paper is to design and analyze the performance of a non-contact heart rate variability (HRV) measuring device based on ultrasound transducers. The rationale behind non-contact HRV measurement is the goal of obtaining a means of long term monitoring of a patient’s heart performance. Due to its complexity as a non-contact measuring device, influential physical quantities, error source and other perturbations were thoroughly investigated. For medical purposes it is of utmost importance to define the target uncertainty of a measuring method from the side of physicians, while it is the role of scientists to realistically evaluate all uncertainty contributions. Within this paper we present a novelty method of non-contact HRV measurement based on ultrasound transducers operating at two frequencies simultaneously. We report laboratory results and clinical evaluations are given for healthy subjects as well as patients with known heart conditions. Furthermore, laboratory tests were conducted on subjects during a relaxation period, and after 1 min physical activity

Usage of Reference Datasets in Testing and Validation of Thermometry Software Modules

The objective of the following paper is to discuss the preparation and usage of adequate input parameters (called reference data sets) for efficient testing of temperature measurement software modules, applying the white‐box software testing strategy. Furthermore, the extension of the suggested approach is presented in an area of intercomparison of temperature measurement software modules. With this new approach better equivalence of the results of the software modules will be possible.