Search results for "Thermocouple"
showing 10 items of 39 documents
Temperature Measurements as a Method for Monitoring Ropes
2020
Due to an increasing demand for operation at sea depths as low as 3000 m and under, the use of fibre ropes for offshore application in deep sea lifting and mooring is increasing. Consequently, improved knowledge is required regarding these ropes’ thermo-mechanical properties and how these properties change as the rope is being used. This paper presents a 2D model of heat transport in the axial and radial directions along a 28 mm diameter fibre rope typically used for offshore applications. The model is combined with temperature measurements during heating and cooling of the rope, using both thermocouples and a thermal camera. Measurements are performed both on a new rope and on a used that …
Composite layer-based analytical models for tool–chip interface temperatures in machining medium carbon steels with multi-layer coated cutting tools
2006
Abstract This investigation is devoted to the thermal problems in dry orthogonal turning of a C45 medium carbon steel with natural contact tools treated with multi-layer coatings with an intermediate Al 2 O 3 layer. New hybrid analytical models for estimating heat partition to the chip and the tool–chip interface temperatures were proposed. Furthermore, the physics-based modelling concept, which applies composite layer approach was developed to estimate the average and maximum steady-state tool–chip interface temperatures in orthogonal turning. The model predictions were compared to appropriate experimental process data using natural tool-work thermocouples and other simulated and measured …
System B, Endo-Twinn and E-Fill. True temperatures inside the canal
2012
Background: The aim of this study is to verify the variations of the temperature inside the root canal with three different gutta-percha heating systems. Materials and Methods: A split-tooth model was built with a lateral groove at 3.5-mm from working length (WL) in order to insert a Chromel-Alumel K-type thermocouple placed in contact with gutta-percha. The thermocouple was connected to a digital thermometer. Sixty obturations were made with medium gutta-percha points. For 20 specimens the System B was used with the Buchanan fine plugger and the temperature was set at 200°C; for other 20 specimens the Endo-Twinn with a fine plugger was used and for the last 20 specimens we used the E-Fill …
Improvement of building wall surface temperature measurements by infrared thermography
2005
By using quantitative thermal scanning of building surface structures, it is possible to access the temperature field. For further calculation of the heat flux exchanged by these structures with the environment, one must quantify as finely as possible the temperature field on the bodies surfaces. For this purpose we have to take into account that real bodies are not black, which implies that a part of the ambient radiation received by the infrared camera detectors is reflected radiation. In this paper, we present a method to quantify the reflected flux by using an infrared mirror, which allows large surface temperature measurements by infrared thermography under near-ambient conditions with…
Increases of intracanal and root surface temperatures during the obturation of canal using the E&Q master system and the system
2010
Objectives: The purpose of our study is to assess the increases of intracanal and root surface temperatures during the obturation of canal system using the E&Q Master System and the System B. Materials and methods: A split-tooth model was built. To measure the temperature, 6 grooves for the placement of thermocouples were made in the buccal half of the model. On the mesial side, three grooves were made at 2, 4 and 6 mm from the anatomical apex and were extended to the root surface, while on the distal side three grooves were made at 2, 4 and 6 mm up to the intracanal portion. In each of these grooves was inserted a type T thermocouple (Copper-Costantana) with a diameter of 0.076 mm. 40 cana…
Control of brain temperature during experimental global ischemia in rats.
1999
Temperature control during experimental ischemia continues to be of major interest. However, if exposure of brain tissue is necessary during the experiment, regional heat loss may occur even when the core temperature is maintained. Furthermore, valid non-invasive brain temperature monitoring is difficult in small rodents. This paper describes a method for both monitoring and maintenance of brain temperature during small animal preparations in a stereotaxic frame. The device used includes an ear-bar thermocouple probe and a small near-infrared radiator. The new equipment permitted to maintain peri-ischemic brain temperature at a desired level while carrying out non-invasive continuous record…
Temperature elevations in endosseous dental implants and the peri-implant bone during diode-laser-assisted surface decontamination
2002
The aim of the study was to investigate temperature elevations in the implant surface and the peri-implant bone during simulated surface decontamination of endosseous dental implants with an 809 nm semiconductor laser. Stepped cylinder implants were inserted into bone blocks cut from resected pig femurs. An artificial peri-implant bone defect provided access for the irradiation of the implant surface. A 600 micron optic fiber was used at a distance of 0.5 mm from the implant surface. Power output varied between 0.5 and 2.5 W in the cw-mode. Power density was between 176.9 and 884.6 Wcm -2 . The bone block was placed into a 37 degree(s)C water bath in order to simulate in vivo thermal conduc…
Optical characterization of phase transitions in pure polymers and blends
2015
To study the optical properties of polymeric samples, an experimental apparatus was designed on purpose and set up. The sample is a thin film enclosed between two glass slides and a PTFE frame, with a very thin thermocouple placed on sample for direct temperature measurement. This sample holder was placed between two aluminum slabs, equipped with a narrow slit for optical measurements and with electrical resistances for temperature control. Sample was enlightened by a laser diode, whereas transmitted light was detected with a photodiode. Measurements were carried out on polyethylene-terephtalate (PET) and two different polyamides, tested as pure polymers and blends. The thermal history impo…
Hydrogen CARS thermometry in H2-N2 mixtures at high pressure and medium temperatures: influence of linewidths models
2000
International audience; In order to improve the accuracy of H2 CARS thermometry, H2 Q-branch CARS spectra have been recorded for various H2-N2 mixtures in a high-pressure cell at different pressures and temperatures (up to 40 bar and 875 K). Due to the low spectral resolution of broadband CARS experiments, the relevant spectral lineshape factor is the linewidth ratio G(Q(3))/G(Q(1)), since Q(1) and Q(3) are the most intense lines of the Q-branch spectrum in this temperature range. For the first time, the speed-inhomogeneous effects are accounted for in the simulation of the CARS profiles. The evaluated temperatures are in good agreement with reference values obtained by thermocouples. The s…
In-Cylinder Heat Transfer Determination Using Impulse Response Method with a Two-Dimensional Characterization of the Eroding Surface Thermocouple
2021
Heat transfer from the cylinder of internal combustion engines has been studied for decades, both in motored and fired configurations. Its understanding remains fundamental to the optimization of engine structures and sub-systems due to its direct effect on reliability, thermal efficiency and gaseous emissions. Experimental measurements are usually conducted using fast response surface thermometers, which give the instantaneous cylinder surface temperature. The transient component of heat flux through the cylinder wall was traditionally obtained from a spectral analysis of the surface temperature fluctuation, whereas the steady-state component was obtained from Fourier's law of conduction. …