Next Article in Journal
An Improved WiFi Positioning Method Based on Fingerprint Clustering and Signal Weighted Euclidean Distance
Next Article in Special Issue
Carbon Nanotubes and Carbon Nanotube Structures Used for Temperature Measurement
Previous Article in Journal
A Low-Cost IoT-Based System to Monitor the Location of a Whole Herd
Previous Article in Special Issue
Strain-Independent Temperature Measurements with Surface-Glued Polarization-Maintaining Fiber Bragg Grating Sensor Elements
Open AccessArticle

Temperature Dependence of the Dynamic Parameters of Contact Thermometers

Institute for Process Measurement and Sensor Technology, Technische Universität Ilmenau, G.-Kirchhoff-Str. 1, 98693 Ilmenau, Germany
*
Author to whom correspondence should be addressed.
Sensors 2019, 19(10), 2299; https://doi.org/10.3390/s19102299
Received: 7 March 2019 / Revised: 13 May 2019 / Accepted: 14 May 2019 / Published: 18 May 2019
(This article belongs to the Special Issue Temperature Sensors)
Contact thermometers are used in a wide temperature range as well as under various media and environmental conditions. The temperature can range from −200 °C to about 1500 °C. In this case, the dynamic parameters (time percentage values tx and time constants τ) depend on temperature. Several effects are superimposed. Constructional and material properties of the thermometer and the installation location affect the dynamic behavior as well as the type and material properties of the object to be measured. Thermal conductivity λ, specific heat capacity c, and density ρ depend on temperature. This temperature dependence can be mutually compensated for (see Section 3). At the same time, the dynamic behavior is also influenced by the temperature-dependent parameters of the medium. When the thermometers are installed in air, for example, the heat transfer coefficient α decreases with increasing temperature, owing to the temperature-dependent material data of the air, at constant speed v. At the same time, heat radiation effects are so strong that the heat transfer improves despite the decreasing convective heat transfer coefficient. In this paper, a number of examples are used to establish a model for the temperature dependence of the dynamic parameters for various thermometer designs. Both numerically and experimentally determined results for the determination of the dynamic characteristic values are included in the consideration. View Full-Text
Keywords: thermometer; dynamic; material properties; temperature dependence thermometer; dynamic; material properties; temperature dependence
Show Figures

Figure 1

MDPI and ACS Style

Augustin, S.; Fröhlich, T. Temperature Dependence of the Dynamic Parameters of Contact Thermometers. Sensors 2019, 19, 2299.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop