Time Resolved Surface Temperature Measurements of the Dite Mkii Bundle Divertor Target Plate Using a Scanning Infrared Camera

1984 ◽  
Vol 6 (2P2) ◽  
pp. 393-398 ◽  
Author(s):  
D. H. J. Goodall ◽  
G. E. Austin ◽  
J. M. Weaver
Keyword(s):  
Surface Temperature ◽  
Infrared Camera ◽  
Temperature Measurements ◽  
Target Plate ◽  
Time Resolved

Time-Resolved Microscale Temperature Measurements of High-Power Semiconductor Lasers

2005 ◽  
Author(s):  
Paddy K. L. Chan ◽  
Amul D. Sathe ◽  
Kevin P. Pipe ◽  
Jason J. Plant ◽  
Paul W. Juodawlkis
Keyword(s):  
Surface Temperature ◽  
Temperature Profile ◽  
Semiconductor Lasers ◽  
High Power ◽  
Nondestructive Method ◽  
Temperature Measurements ◽  
Semiconductor Diode ◽  
Nonradiative Recombination ◽  
Time Resolved ◽  
Time Resolved Measurements

Nonradiative recombination and other heat generation processes affect both the performance and lifetime characteristics of semiconductor diode lasers. This is especially true for high-power devices, where facet heating due to nonradiative recombination can lead to catastrophic optical damage (COD). Here we present for the first time temperature measurements of a semiconductor laser in which the surface temperature profile (and hence the current density profile) of the laser is measured as it evolves in time. The laser studied is a λ=1.55μm 1-cm-long InGaAsP/InP watt-class slab-coupled optical waveguide laser (SCOWL). The ridge width of the SCOWLs examined here is approximately 5 μm. Temperature measurements are taken using multiple microthermocouples with sizes less than 20μm. Surface temperature fluctuations in time are seen to be quite large, as high as 20% of the total temperature increase of the device. Time-resolved measurements allow us to see both positive correlation (in which the temperature rises at the same time across an area of the device) as well as negative correlation (in which part of the device gets hot at the same time as another part of the device gets cold). Negative correlations are likely due to facet heating processes which cause bandgap shrinkage and hence increased current flow to a facet, pulling current away from the center of the device. Time-resolved measurements of the surface temperature profile therefore show promise as a nondestructive method for characterizing the failure mechanisms of a laser, as facet damage over time is otherwise very difficult to measure before the COD runaway process destroys the device.

scholarly journals Water-Stressed Plants Do Not Cool: Leaf Surface Temperature of Living Wall Plants under Drought Stress

2021 ◽  
Vol 13 (7) ◽  
pp. 3910
Author(s):  
Michael Gräf ◽  
Markus Immitzer ◽  
Peter Hietz ◽  
Rosemarie Stangl
Keyword(s):  
Drought Stress ◽  
Surface Temperature ◽  
Leaf Surface ◽  
Canopy Temperature ◽  
Infrared Camera ◽  
Control Group ◽  
Thermal Cameras ◽  
Living Wall ◽  
Leaf Level ◽  
Vertical Greening

Urban green infrastructures offer thermal regulation to mitigate urban heat island effects. To gain a better understanding of the cooling ability of transpiring plants at the leaf level, we developed a method to measure the time series of thermal data with a miniaturized, uncalibrated thermal infrared camera. We examined the canopy temperature of four characteristic living wall plants (Heuchera x cultorum, Bergenia cordifolia, Geranium sanguineum, and Brunnera macrophylla) under increasing drought stress and compared them with a well-watered control group. The method proved suitable to evaluate differences in canopy temperature between the different treatments. Leaf temperatures of water-stressed plants were 6 to 8 °C higher than those well-watered, with differences among species. In order to cool through transpiration, vegetation in green infrastructures must be sufficiently supplied with water. Thermal cameras were found to be useful to monitor vertical greening because leaf surface temperature is closely related to drought stress. The usage of thermal cameras mounted on unmanned aerial vehicles could be a rapid and easy monitoring system to cover large façades.

Characterization of Fouled Flat Sheet Membranes by Infrared Thermography

2014 ◽  
Author(s):  
Kennethrex O. Ndukaife ◽  
George Agbai Nnanna
Keyword(s):  
Surface Temperature ◽  
Infrared Thermography ◽  
Spectral Power ◽  
Membrane Surface ◽  
Infrared Camera ◽  
Feed Solution ◽  
Feed Concentration ◽  
Ir Camera ◽  
Measure Surface Temperature

An Infrared thermography (IRT) technique for characterization of fouling on membrane surface has been developed. The emitted spectral power from the fouled membrane is a function of emissivity and surface morphology. In this work, a FLIR A320 IR camera was used to measure surface temperature and emissivity. The surface temperature and the corresponding emissivity value of various areas on the fouled membrane surface is measured by the infrared camera and recorded alongside its thermogram. Different fouling experiments were performed using different concentrations of aluminum oxide nanoparticle mixed with deionized water as feed solution (333 ppm, 1833 ppm and 3333 ppm) so as to investigate the effect of feed concentration on the degree of fouling and thus its effect on the emissivity values measured on the membrane surfaces. Surface plots in 3D and Line plots are obtained for the measured emissivity values and thickness of the fouling deposit on the membrane surface respectively. The results indicate that the IRT technique is sensitive to changes that occur on the membrane surface due to deposition of contaminants on the membrane surface and that emissivity is a function of temperature, surface roughness and thickness of the specimen under investigation.

Sign in / Sign up

Export Citation Format

Share Document