Real Temperature Distribution on the Surface of Underfloor Heating

2015 ◽  
Vol 5 (5) ◽  
pp. 137-151
Author(s):  
Henryk G. Sabiniak ◽  
Karolina Wiśnik
Keyword(s):  
Temperature Distribution ◽  
Real Temperature

Thermoreflectance Measurements of the Temperature Distributions in Laser Diodes with Non Injected Facet

2006 ◽  
Vol 916 ◽  
Author(s):  
Tomasz Ochalski ◽  
Dorota Pierscinska ◽  
Kamil Pierscinski ◽  
Andrzej Malag ◽  
Agata Jasik ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Active Region ◽  
Laser Diodes ◽  
Damage Level ◽  
Temperature Distributions ◽  
Temperature Maps ◽  
Real Temperature ◽  
Front Facet ◽  
Better Than ◽  
Made In

AbstractNon Injected Facet (NIF) lasers were developed to increase catastrophic optical damage level of the devices. In this work we present the analysis of the laser diodes (LD) front facet temperature distribution. Micro-thermoreflectance technique is used to perform a detailed temperature maps of the operating LDs. Such a technique gives us temperature maps with a spatial resolution better than 1mm and area of the maps covers active region and substrate crystal. We demonstrate micro thermoreflectance as a perfect tool to determine real temperature distribution of the operating laser diode front facet. Examined series of LDs under investigation have been made in two different ways. Major point of this work is comparison of the front facet temperature distribution of devices with and without injected facets. We compare temperature value and temperature distribution in the waveguide region in both types of the LDs. In our experiment NIF laser diodes exhibit facet temperatures increased by a factor of 1.4.

Investigation of the Applicability of the Thermo Photo Analysing Method in Die Casting Technology

2010 ◽  
Vol 659 ◽  
pp. 523-528
Author(s):  
Monika Tokár ◽  
Levente Tóth ◽  
Tamás Rick ◽  
Tamás Mende
Keyword(s):  
Temperature Distribution ◽  
Automotive Industry ◽  
Cycle Time ◽  
Analytical Method ◽  
Die Casting ◽  
Customer Requirements ◽  
Casting Technology ◽  
Die Surface ◽  
Pressure Die Casting ◽  
Real Temperature

As customer requirements are continuously growing in connection with up-to-date castings, it is essential for firms interested in the international market to use modern fittings and instruments, which serve for high quality controls, even for manufacture control within each manufacturing process. For example, the thermo camera is such a measuring instrument we can use for measuring the thermo loss of the furnace, concluding to the inadequately insulating parts, or can even make the thermo profile of the surface of the die. In our work, we were analysing the temperature distribution of the die surface by using a thermo camera, during the manufacture of aluminium casting of automotive industry made by high pressure die casting technology. In pressure die casting, spraying the surface of the casting die with detaching material is a really important technological step, and spraying time – as a part of cycle time influencing productivity – is a very significant parameter. The main functions of spraying include cooling the hot surfaces of die halves, lubrication of the moving parts and helping the ejection of the casting. During our analyses we changed the spraying time of the die, and we took temperature distribution photographs of the stationary die plate by a thermo camera. The only function of the analytical method using a thermo camera is to make the differences in temperature, caused by the changes of the spraying time in the die, comparable in a moment in time. The temperatures taken by us are exact, real temperature values of the die, but these are strongly time-dependent and refer to a certain period of cycle time. It makes possible to compare the temperatures of the die surface in different places in a certain moment in time. We elaborated an analytical method, by which it can be decided if the analysis of the thermo photos is a suitable method for examining the effect – on the casting structure – of spraying time of the die.

scholarly journals Fibre Optic FBG Sensors for Monitoring of the Temperature of the Building Envelope

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1207
Author(s):  
Janusz Juraszek ◽  
Patrycja Antonik-Popiołek
Keyword(s):  
Temperature Distribution ◽  
Relative Humidity ◽  
Test Chamber ◽  
Winter Season ◽  
Building Envelope ◽  
Temperature Measurements ◽  
Fibre Bragg Grating ◽  
Fibre Optic ◽  
Fbg Sensors ◽  
Real Temperature

Standard sensors for the measurement and monitoring of temperature in civil structures are liable to mechanical damage and electromagnetic interference. A system of purpose-designed fibre optic FBG sensors offers a more suitable and reliable solution—the sensors can be directly integrated with the load-bearing structure during construction, it is possible to create a network of fibre optic sensors to ensure not only temperature measurements but also measurements of strain and of the moisture content in the building envelope. The paper describes the results of temperature measurements of a building 2-layer wall using optical fibre Bragg grating (FBG) sensors and of a three-layer wall using equivalent classical temperature sensors. The testing results can be transmitted remotely. In the first stage, the sensors were tested in a climatic test chamber to determine their characteristics. The paper describes test results of temperature measurements carried out in the winter season for two multilayer external walls of a building in relation to the environmental conditions recorded at that time, i.e., outdoor temperature, relative humidity, and wind speed. Cases are considered with the biggest difference in the level of the relative humidity of air recorded in the observation period. It is found that there is greater convergence between the theoretical and the real temperature distribution in the wall for high levels (~84%) of the outdoor air relative humidity, whereas at the humidity level of ~49%, the difference between theoretical and real temperature histories is substantial and totals up to 20%. A correction factor is proposed for the theoretical temperature distribution.

Analysis of the Front Facet Temperature in Laser Diode With Non Absorbing Mirror

2005 ◽  
Vol 891 ◽  
Author(s):  
Tomasz Jan Ochalski ◽  
Dorota Pierscinska ◽  
Andrzej Malag
Keyword(s):  
Temperature Distribution ◽  
Spatial Resolution ◽  
Laser Diode ◽  
High Spatial Resolution ◽  
Laser Diodes ◽  
Optical Damage ◽  
Damage Level ◽  
Temperature Maps ◽  
Real Temperature ◽  
Front Facet

ABSTRACTNon-absorbing mirror (NAM) lasers, also known as window lasers, were developed to increase catastrophic optical damage level of the devices. In this work we present the analysis of the laser diodes (LD) front facet temperature distribution. Micro-thermoreflectance technique is used to perform a detailed temperature maps of the operating LDs. Such a technique gives us temperature maps with a high spatial resolution equal 0.6μm. We demonstrate micro thermoreflectance as a perfect tool to determine real temperature distribution of the operating laser diode front facet.

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