The Influence of High Temperature Weather on Human Body Temperature Measurement by Infrared Thermal Imaging Thermometer

Infrared thermography thermometer is a non-contact temperature measuring equipment, which is widely used in the stage of large-scale epidemic of the covid-19 pandemic. It is used for rapid screening of human body temperature in crowded places at the entrance and exit of airports, docks, shopping malls, stations and schools. But when the outdoor temperature approaches or exceeds the body temperature in summer, can this method of measuring body surface temperature by infrared thermal imager be used as a standard for screening fever? Under the condition of high temperature in summer, the field experiment of measuring body temperature by infrared thermal imager is carried out, the experimental results are analyzed. We recommend the use of relative temperature difference for screening patients with fever.

Study on the Causes of Secondary Cracks of the Eave Wall Mural of Daxiong Hall at Fengguo Temple in Yixian, Liaoning, China

Built in Kaitai nine years of Liao Dynasty (1020 A.D.), the Daxiong Hall of Fengguo Temple in Yixian County, Liaoning Province, is one of the largest existing ancient single-eave wooden structure in China. There are nearly 470m 2 murals of Yuan Dynasty on the four walls of the hall. Since the in-situ reinforcement and protection of the mural were carried out in the 1980s in cooperation with the maintenance and restoration project of the main hall, the seriously developed cracks have become the primary factor affecting the structural stability of the mural. In order to find out the macroscopic causes of secondary cracks, endoscope, infrared thermal imager, three-dimensional laser scanner and other equipment were applied to study the relations between cracks’ attitude and structural defects of the eave wall, as well as the pathway that external environment act on the mural noumenon through comprehensive investigation, and the idea of restoring the stability of the mural by blocking the air channel and offsetting the environmental stress is put forward.

Study on Optical and Thermal Uniformity of LED Filament Based on Flip Chip1

The LED filament has become a research hotspot in industrial and academic fields. The filament was fabricated by the flip LED chip, and its optical and thermal uniformity was tested and analyzed in detail. The color temperature (CT), brightness and surface temperature (ST) of LED filament at different positions was measured by BM-7 aiming point luminance meter and Ti-32 infrared thermal imager respectively. The experimental results show that the brightness and ST of the filament conformed to the Lambert distribution. The filament was simulated by lightTools optical software and FLOEFD thermal software respectively, and the simulated illumination and temperature distribution were the same as the test results. Experimental results show that the CT and brightness of LED filament on both sides was 4.23% and 9.27% lower than that of the middle position, respectively. The ST difference of the whole device was 9.80 C. The thermal parameters of LED filament were simulated by FLOEFD software. The simulated results indicated that the ST was distributed with high level in the middle and low level at both sides, the results of simulation and experiment are consistent. Therefore, it was reveled that the LED filament prepared based on the LED flip chip has good optical and thermal uniformity and be feasible as a new type of LED light source.

Detection of Hotspots and Performance Deteriotations in PV Modules under Partial Shading Conditions Using Infrared Thermography

Operating photovoltaic (PV) modules are frequently shaded by nearby structures, vegetation, droppings, etc., and this reduces the effective incident solar radiation received by the modules. Shading also reduces the power output of PV modules and, under certain conditions, causes the formation of hotspots. In this study, a wide variety of partial shading scenarios were investigated to evaluate their effects on the output current, voltage and efficiencies, and hotspot formation in mono-crystalline and poly-crystalline PV modules operating under the ambient conditions experienced in Nsukka, Nigeria. Sixteen shading cases were considered, including 20%, 40%, 60% and 80% of the modules’ surface areas shaded parallel to the long sides, parallel to the short sides, diagonally and randomly. Test ambient conditions, module outputs and surface thermal patterns were simultaneously monitored using a digital solarimeter, multimeter and infrared thermal imager, respectively. The outputs of the modules decreased to almost zero when as little as 40% of the module surfaces were shaded, with the reductions in performance being more severe in the mono-crystalline modules than in the poly-crystalline modules. The infrared thermography revealed the thermal patterns under the different shading conditions and showed that the random shading of the modules was the most likely to result in hotspots.