Minimum temperature difference perceived—a new approach to assess undersampled thermal imagers

1999 ◽  
Vol 38 (5) ◽  
pp. 773 ◽  
Author(s):  
Wolfgang Wittenstein
Keyword(s):  
Temperature Difference ◽  
Minimum Temperature ◽  
New Approach ◽  
Thermal Imagers

scholarly journals METHOD OF CALCULATING THE MINIMUM TEMPERATURE DIFFERENCE PERCEIVED OF UNDERSAMPLED THERMAL IMAGERS

2019 ◽  
Vol 0 (2) ◽  
pp. 78-82
Author(s):  
Valentin G. Kolobrodov ◽  
Mykola M. Lutsiuk ◽  
Volodymyr M. Tiagur
Keyword(s):  
Temperature Difference ◽  
Minimum Temperature ◽  
Thermal Imagers

Minimum temperature difference detected by the thermal radiation of objects

1994 ◽  
Vol 35 (5) ◽  
pp. 715-732 ◽  
Author(s):  
Igor I. Taubkin ◽  
Michael A. Trishenkov ◽  
Nikolai V. Vasilchenko
Keyword(s):  
Thermal Radiation ◽  
Temperature Difference ◽  
Minimum Temperature

scholarly journals Virtual MRTD – an indirect method to measure MRTD of thermal imagers using computer simulation

2020 ◽  
Vol 50 (4) ◽  
Author(s):  
Krzysztof Chrzanowski ◽  
Nguyen Hong Viet
Keyword(s):  
Computer Simulation ◽  
Temperature Difference ◽  
Measurement Method ◽  
Indirect Method ◽  
Lower Cost ◽  
Human Observer ◽  
Thermal Imager ◽  
Spatial Frequencies ◽  
Thermal Imagers ◽  
Measurement Concept

Minimum resolvable temperature difference (MRTD) is considered as the most important parameter of thermal imagers. A new method of MRTD measurement without drawbacks of other methods is presented in this paper. Proposed MRTD measurement method coded as virtual MRTD is based on a three steps measurement concept using semi-automatic objective measurements and computer simulation. First, objective parameters of the tested thermal imager are measured. Second, software simulates this tested thermal imager and generates the image of 4-bar target of specified spatial frequency (size) and contrast (temperature difference). Third, a human observer analyses the images of the 4-bar target generated by the software on the screen of PC set and measures MRTD of the simulated thermal imager at specified set of spatial frequencies. The proposed method offers higher measurement speed, lower cost and typically better accuracy in comparison with the typical MRTD measurement method.

scholarly journals Thermal Performance of Micro Hotplates with Novel Shapes Based on Single-Layer SiO2 Suspended Film

Micromachines ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 514 ◽  
Author(s):  
Qi Liu ◽  
Guifu Ding ◽  
Yipin Wang ◽  
Jinyuan Yao
Keyword(s):  
Power Consumption ◽  
Mechanical Strength ◽  
Thermal Performance ◽  
Temperature Difference ◽  
Minimum Temperature ◽  
Single Layer ◽  
Temperature Uniformity ◽  
Infrared Images ◽  
Reticular Structure ◽  
The One

In this paper, two kinds of suspended micro hotplate with novel shapes of multibeam structure and reticular structure are designed. These designs have a reliable mechanical strength, so they can be designed and fabricated on single-layer SiO2 suspended film through a simplified process. Single-layer suspended film helps to reduce power consumption. Based on the new film shapes, different resistance heaters with various widths and thicknesses are designed. Then, the temperature uniformity and power consumption of different micro hotplates are compared to study the effect of these variables and obtain the one with the optimal thermal performance. We report the simulations of temperature uniformity and give the corresponding infrared images in measurement. The experimental temperature differences are larger than those of the simulation. Experimental results show that the lowest power consumption and the minimum temperature difference are 43 mW and 50 °C, respectively, when the highest temperature on the suspended platform (240 × 240 μm2) is 450 °C. Compared to the traditional four-beam micro hotplate, temperature non-uniformity is reduced by about 30–50%.

Effects of day-night temperature combinations under constant day length on emergence and early growth of sericea lespedeza genotypes

2007 ◽  
Vol 87 (1) ◽  
pp. 77-81
Author(s):  
K. L. Kalburtji ◽  
J. A. Mosjidis ◽  
A. P. Mamolos
Keyword(s):  
Temperature Difference ◽  
Minimum Temperature ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Day Length ◽  
Night Temperature ◽  
Sericea Lespedeza ◽  
Leaf Dry Weight ◽  
Maximum Minimum ◽  
Number Of Branches

Establishment of sericea lespedeza [Lespedeza cuneata (Dumont de Courset) G. Don.] in southeastern USA is difficult. Seedling emergence may be related to the range of temperatures prevalent during establishment. A growth chamber study was undertaken to measure the effect of temperature on seedling emergence of 56 sericea lespedeza genotypes. Main treatments were: (1) plants grown at three day-night temperature combinations with maximum/minimum temperature difference of 14°C. The temperature combinations were 22/8°C, 27/13°C, and 32/18°C; (2) plants grown at three day-night temperature combinations with maximum/minimum temperature difference of 7°C. This was accomplished by lowering the day temperature and keeping the night temperature the same as above. Emergence was reduced by about 27% with reduction of 7°C in day-night temperature within the range of temperatures used. Plant height, leaf dry weight, stem dry weight and number of branches were very sensitive to temperature combinations. Increases in temperature caused increases in height, leaf dry weight, stem dry weight and number of branches of all genotypes. Further screening of sericea for emergence and growth under low temperature may lead to cultivars with more vigorous seedlings that can be better established early in the season. Key words: Plant growth, temperatures, seedling emergence, Sericea, southern USA

Numerical Simulation of Temperature Field in the Cyclone

2012 ◽  
Vol 614-615 ◽  
pp. 208-211
Author(s):  
Zhen Wei Zhang ◽  
Ying Yu ◽  
Jie Leng ◽  
Su Juan Zhang
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Turbulence Model ◽  
Temperature Difference ◽  
Minimum Temperature ◽  
Maximum Temperature ◽  
Inlet Tube ◽  
Higher Temperature ◽  
Air Compression

The temperature distribution of the cyclone was analyzed in the presented work, which was imitated by using RSM turbulence model of software FLUENT. Temperature difference in different regions is less than one centigrade degree with the maximum temperature in the cone part and the minimum temperature in inlet tube and cylinder part of the cyclone, what’s more, the temperature is relatively higher near the wall. The air compression can lead the higher temperature in the lower part, so the cone part has the maximum temperature. The higher temperature near the wall is caused by the friction between the wall and flow.

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