Fever is an important clinical manifestation of new coronavirus pneumonia. In public health emergencies, it is necessary to start fever screening to control the rapid spread of influenza. The measurement and calibration technology of infrared body temperature screening instrument has been developed in recent years, and there are still shortcomings in the field use of infrared screening instrument. In order to fully understand the performance parameters of infrared screening instrument, further improve the performance of equipment and establish a unified reference standards. This study analysis and investigates the test results and performance parameters of multiple screening machines, improving the standardization and effectiveness of fever screening. The results indicate that blackbody can effectively reduce the error, avoid the appearance of larger error, large temperature fluctuation, and restrain the phenomenon of temperature drift to a certain extent.
Infrared temperature measurement has a wide range and more applications, due to infrared temperature measurement does not need to contact with the object under test. However, the accuracy of infrared temperature measurement is difficult to reach a satisfactory degree, which limits the development and application of infrared temperature measurement method. This study explores how the atmospheric transmittance affects the temperature measurement accuracy of infrared thermal imager. Based on the composition of atmosphere, the major reason affecting atmospheric transmittance have been found. Meanwhile, according to the influence of water vapor and carbon dioxide absorption, aerosol, atmospheric molecule and other suspended particles, attenuation of atmospheric transmittance caused by complex weather conditions, such as rain and snow. Atmospheric transmission model is proposed, and the theoretical formula for calculating atmospheric transmittance is obtained.
Dry block furnaces are widely used in on-site measurement and calibration of food, petrochemical, pharmaceutical, semiconductor, and other manufacturing enterprises for their advantages such as pollution-free, simple operation, easy to carry, fast rise and fall, and wide usable temperature range. The accuracy of dry-block furnace temperature measurement is always a problem for calibrator. The stability of dry-block furnace is an important factor affecting its accuracy. In conventional dry block calibrators, the drift of the internal reference thermometer and temperature gradients in the normalization block are the main contributors to the accuracy. However, the experimental comparison of the stability of the different brands dry-block furnace at different calibration temperatures is rare. we carry out validation and evaluation project to evaluate the stability of dry-block furnaces of two brands at home and abroad, the relationship between calibration temperature and stability of dry well furnace is analyzed by experiments. The results show that the overall stability of RTC158 is better than that of Const660. The measurement accuracy of RTC158 is better than that of Const660. We hope that this experiment can provide more comprehensive and reliable experimental data for the application of dry well furnace in field temperature calibration, so as to improve the accuracy of temperature measurement.
Unilateral external fixators are commonly used to stabilize the fractured tibia bone. Compared with static fixation, axial dynamic motion can be used for promoting callus formation, improving bone healing at fracture sites. Moreover, non-axial motions are not conductive to promoting bone healing and remodeling. However, a fixator-bone system with 7(DOFs) can not achieve both fracture correction and axial dynamic motion. Maybe it is easy to think that this problem could be solved by adding one DOF for fixator structure. However the increased structural flexibility could not be able to meet the demands of lower cost and size, and higher stiffness. Thus, how a fixator-bone system with 7 DOFs not only can realize fracture correction, but also complete axial dynamic motion as far as possible. So far, researchers have never solved this problem. Therefore, we establish a mathematical model based on the 7 DOFs Orthofix fixators, and try to use the genetic algorithm method to reduce the tangential displacements in the process of axial dynamization after fracture correction. The results suggest that the use of genetic optimization algorithm can effectively reduce tangential displacement. This study helps facilitate appropriate and flexibility application of fixators to better control axial dynamic motion and decrease tangential displacements.
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