Temperature Measurement Device Research Articles

Developing the optimized control scheme for digital light processing 3D printing by combining numerical simulation and machine learning-guided temperature prediction

Digital light processing (DLP) 3D printing has attracted significant attention for its rapid printing speed, high accuracy, and diverse applications. However, the continuous DLP printing process releases substantial heat, resulting in a swift temperature rise in the curing area, which may lead to printing failures. Due to the lack of effective means to measure real-time temperature changes of the curing surface during continuous DLP 3D printing, the prevailing approach is to predict temperature variations during printing via numerical simulation. Nevertheless, temperature prediction methods relying solely on numerical simulation tend to be slow and overlook heat exchange dynamics during printing, potentially resulting in prediction inaccuracies, particularly for complex models. To address these issues, this paper proposes a method to combine numerical simulation and a machine learning approach for temperature prediction in the DLP 3D printing process, along with a printing control scheme generation method. Firstly, the m+nth order autocatalytic kinetic model considering the light intensity and the Beer–Lambert law are employed to formulate the heat calculation equation for the photopolymer resin curing reaction. Subsequently, a heat exchange calculation equation is established based on Fourier heat conduction law and Newton’s cooling equation. A numerical simulation model for temperature changes during the printing process is then developed by integrating the heat calculation equation, heat exchange calculation equation, and measurement data from Photo-DSC. Furthermore, a temperature measurement device for the printing process is designed to validate the accuracy of the numerical simulation. Following this, an improved Long Short-term Memory (LSTM) network is proposed, using temperature change data generated by the numerical simulation model to train the network for rapid (2×10−4s/layer) prediction of temperature changes during printing. Finally, aiming for the shortest printing time, an optimized control scheme planning algorithm and a target function are designed based on the model’s temperature change data and the monomer’s flash point to ensure the temperature remains below this threshold. This algorithm can automatically generate the optimal printing control scheme for any model. Experimental results demonstrate that the proposed temperature prediction method can predict temperature variation accurately. Based on this, the generated printing control scheme can guarantee efficient and high-quality manufacturing for anymodel.

Experimental investigation on product and temperature distribution in a continuous flow packed-bed reactor for dodecahydro-N-ethylcarbazole dehydrogenation

The dehydrogenation of dodecahydro-N-ethylcarbazole (H12-NEC) generates enormous gas accompanied by intense heat absorption, affecting heat and mass transfer in porous catalysts. A packed-bed reactor equipped with a temperature measurement device was designed to investigate the continuous flow dehydrogenation of H12-NEC. The effects of weight hourly space velocity (WHSV), reaction temperature, catalyst particle size, and pressure were evaluated. The results reveal that the volume flow rate of hydrogen will increase with the increase of WHSV. And the reduction of gas–liquid ratio and catalyst particle size facilitates heat transfer causing a more uniform axial temperature distribution within the reactor. As the temperature rises, the hydrogen yield increases along with more by-products. 456 K and 2 mm of catalyst particle size are determined to be the optimal reaction conditions in the study, achieving the hydrogen production rate of 9.61 molH2·gPd-1·h-1. With pressure increasing, the hydrogen yield gradually decreases, but the decreased evaporation of H12-NEC results in a smaller temperature difference between the reactor and heating wall. A comparison with the thermodynamic equilibrium model reveals that the effect of pressure on chemical equilibrium may be more significant than the temperature.

Development of Best Practice Guideline for the management of hot holes in surface coal mines

Surface coal operations in which mining activities are conducted above old underground workings experience hot holes after drilling. In a coal mine, hot holes are defined as shot holes, which after being drilled have an in-hole ambient temperature of 40°C or above or show a temperature increase of 3°C or more during monitoring. Hot holes and other cavities, such as cracks, pose health and safety risks to workers, such as exposure to hot air and high concentrations of noxious gases released from these holes. In addition, workers may be exposed to premature detonation of explosives caused by in-hole temperature increases and chemical reactions. To this end, Coaltech Research Association commissioned a project to develop a Best Practice Guideline for the management of hot holes. This paper is a compilation of the activities conducted in the development of the Best Practice Guideline between 2021 and 2022. The activities included a review of standard operating procedures and hot-hole temperature-measuring and -monitoring devices, and the assessment of current hot-hole procedures at selected mines. The results indicated that management of hot holes requires a focus on pre-emptive risk assessment of mining blocks, identification of hot holes using the correct temperature-measuring devices, and continuous monitoring of hot holes from the time of drilling until just before blasting. Hot-hole management accessories, such as polyvinyl chloride sleeves, were found to be effective in insulating the hot-hole emulsion from the rock mass temperature, thus preventing the potential for premature detonation.

Numerical Study and Structural Optimization of Water-Wall Temperature-Measurement Device for Ultra-Supercritical Boiler.

The temperature of the water wall in the furnace chamber is extremely important for the daily operation of a boiler. Considering the high temperature and dusty environment in the furnace, a temperature measurement device mainly composed of four parts (armored temperature sensor, in-furnace heat-collecting block, out-furnace fixing base, and protective cannula) was designed in this study, which could be used to directly obtain the temperature of the in-furnace water-wall. Numerical simulations of temperature measurement devices with different heat-collecting block structures were carried out using the computer fluid dynamics method. After comparing the measurement accuracy and considering the practical application scenarios, the optimized heat-collecting block structure with a specific expansion gap (0.5 mm wide and 4 mm deep) was selected for practical application. Such a temperature measurement device was then applied to a 1000 MW ultra-supercritical coal-fired boiler in China, and the tested in-furnace water-wall temperature data were in good agreement with relevant research. Compared with the conventional temperature measurement device arranged outside the furnace, the in-furnace water-wall temperature-measurement device adopted in this study has a more sensitive response characteristic and can directly reflect the temperature of the water wall inside the furnace. In addition, it can also reflect the local slag formation state of the water wall and has a long service life.

Analysis of cooling effects and measurement errors in water-cooled thermocouples for total temperature measurement in aviation engine combustion chambers

Accurate measurement of the total temperature in the main combustion chamber of an aviation engine is crucial for assessing engine performance. However, a significant challenge exists in balancing the heat transfer errors caused by the necessary cooling of the measuring device with measurement precision. The research employs a combination of numerical simulations and experimental methods to investigate this issue. The numerical simulations utilized the Reynolds-averaged Navier Stokes (RANS) coupled with a conjugate heat transfer approach to study the primary flow characteristics and heat transfer properties within the combustion chamber and the probe body. The experiments were conducted in a heat-calibration wind tunnel, validating the results of the numerical simulations. The results show that by implementing water cooling, the probe's body temperature can be reduced from 1200 °C in high-temperature conditions to 400 °C, with localized temperature imbalances still present in the edge areas of the probe. Tracing the cooling water path reveals that the vertical bends in the internal channels lead to an increase in localized pressure loss of the cooling water. The study quantitatively analyzes measurement errors caused by three heat transfer modes: radiation, convection, and conduction. In low-load conditions of the combustion chamber, heat conduction plays a dominant role, with measurement errors due to conduction reaching up to 70 % of the total measurement error. Radiation further increases the temperature measurement errors of the thermocouple's junctions near the chamber wall. As the combustion chamber temperature increases, entering high-load conditions, the cooling effect of water becomes limited, reducing conduction errors and increasing radiation errors. In these conditions, radiation errors constitute 60–70 % of the total measurement error. It suggests the importance of considering temperature corrections when using water-cooled temperature measurement devices. The research reveals several crucial insights regarding the performance and limitations of water-cooled thermocouples.

Generation of cutting heat and simulation of core tube wall temperature during coring in primary structure coal seam

When the drilling core method is used to determine the coalbed gas content, the cutting heat generated by the core bit cutting coal will increase the core tube temperature, and the excessively high core tube temperature will have an heating effect on the coal core, which will accelerate the coal core gas desorption rate and increase the gas loss amount. The generation of cutting heat of core bit and the measurement of core tube temperature are the basis for grasping the gas desorption law of coal core and projecting the amount of gas loss. Firstly, the self-developed core tube temperature measurement device was used to conduct on-site core temperature measurement experiments at different cutting speeds. Then, the cutting temperature of core bit was solved by establishing thermodynamic model for cutting coal and heat transfer model of cutting edge. Finally, based on the thermal conductivity characteristics of the core tube, the core tube temperature at different cutting speeds was simulated, and the simulated temperature was compared with the on-site measured temperature to verify the reliability of the model. The results show that when coring in primary structural coal, the temperature change trend of core tube wall temperature measurement point at different cutting speeds is basically consistent, the temperature measurement point at the front end of the core tube mainly goes through a relatively stable period in the drilling process, a sharp rising period in the cutting process, a slow rise and cooling period in the withdrawal process. However, the temperature measurement point at the back end of the core tube wall mainly goes through a relatively stable phase and a slowly increasing phase. The temperature rise of the core bit and the core tube wall are significantly positively correlated with the cutting speed. When coring in hard coal seam and the core depth is not large, the cutting heat generated by the core bit and the coal body is the dominant factor for the temperature rise of the core tube. The core tube wall temperature calculated using the model matches well with the field measured temperature, and the error is small, which fully shows that the coring thermodynamic model is feasible. This study provides a basis for further research on the dynamic distribution characteristic of coal core temperature during coring, which is of profound significance to calculate the gas loss and coalbed gas content.

Transient temperature measurement of silicon carbide Schottky barrier diode based on thermal reflection.

In this article, we present a transient temperature detection device for silicon carbide (SiC) Schottky barrier diodes (SBDs) based on thermal reflection theory. We constructed a thermal reflection temperature measurement device based on a 530-nm green laser. This device is more suitable for transient temperature measurement of SiC SBDs than previous thermal reflection equipment. The accuracy of temperature measurement by our device was confirmed by comparison with the results of infrared thermal imaging. The high temporal resolution characteristics of the thermal reflection technology allowed the detection of millisecond-level transient temperature changes in SiC SBDs. In addition, we investigated the complementarity of transient temperature change curves during heating and cooling processes, as well as the reasons for the differences between these curves. Finally, we used the structural function method combined with the Bayesian deconvolution algorithm to obtain the thermal resistance along the heat flow path of the device and validated the results using an established thermal resistance testing method.

COMPARISON OF DIFFERENT BUILDING MATERIALS FOR ENHANCEMENT OF BUILDING COMFORT

As people spend more time indoors, the need for buildings that are not only energy-efficient but also comfortable and healthy has become more critical. The objective of this project is to compare the performance of different building materials in enhancing the building comfort by monitoring the temperature levels of three different rooms on an hourly basis. In order to achieve this objective, a sensor was designed and installed in each room to record the temperature readings. The data collected by the sensors was then analyzed and compared to determine the effect of different building materials on the indoor environment. The experiment was conducted over a period of 21 days and the data was collected for each hour of the day. The results of the study indicated that the choice of building material has a significant impact on the indoor environment, with some materials performing better than others in terms of maintaining comfortable temperature levels do. The data collected was then presented in graphical form to facilitate easy comparison of the performance of different building materials. Overall, the findings of this study can be used to inform decisions about the choice of building materials for different construction projects in order to optimize the building comfort and ensure a healthy indoor environment. Keyword- Temperature measurement device, Enhancement of building comfort, Three Different Building Materials clay burnt Brick masonry, Stone Masonry and AAC Block

Rancang bangun thermocouple data logger multichannel berbasis Arduino Mega 2560

Measuring temperature using a data logger is a suitable choice for temperature measurements of an object. The availability of Arduino as a microcontroller has become a preference for developments, especially in temperature measurement devices. One temperature sensor that has good accuracy is the Adafruit MAX31856. This research aims to design a low-cost temperature data logger. The method used in this research is the design and build method. The results of this research show that the temperature data logger works well. This is indicated by the close correlation of the measurement results from each sensor. This applies to measurements of heated water as well as water taken from the dispenser.

СОВЕРШЕНСТВОВАНИЕ ТЕХНОЛОГИИ ДИАГНОСТИРОВАНИЯ ОПОРНЫХ УЗЛОВ ТРАНСМИССИИ АВТОМОБИЛЯ КАМАЗ-55111

The paper presents trends in the development of automatic diagnostics systems for mechanical transmission units. (Research purpose) The research purpose is substantiating the technology of automatic identifying the pre-failure condition of transmission units. (Materials and methods) The supporting components of the KamAZ-55111 transmission with rolling bearings 50412 and 53610 were chosen as the research material. The analysis of existing methods of labor intensity, methods for calculating machine parts, reference information on bearings, finite element analysis of temperature fields and regression analysis were used. (Results and discussion) The characteristics of the indicators of the transmission support units (rolling bearings) were described, methods of their diagnosis were considered. The forces acting on the bearings on the secondary and intermediate shafts of the KamAZ-55111 car were calculated. The design, technological and operational parameters were used to calculate the temperature in the friction zone. In order to improve the diagnostic technology, temperature fields were simulated using the APM FEM CAD Compass 3D application. A device for automatic temperature measurement in the friction zone and a sensor for temperature measurement have been developed. (Conclusions) The reliability of the transmission support units of agricultural machinery is affected by the working conditions. It was established that the most effective method of diagnosing the complexity of the transmission is the method of thermodiagnostics. Analysis of the temperature in the friction zone of bearings 50412 and 53610 from first to fourth gear showed a decrease in temperature. The study of temperature field maps made it possible to establish the relationship between the temperatures in the friction zone and in the control zone of bearings 50412 and 53610. A recorder for automatic monitoring of the technical condition of the nodes has been developed and tested.

Development of Temperature Sensor Based on AlN/ScAlN SAW Resonators

Temperature monitoring in extreme environments presents new challenges for MEMS sensors. Since aluminum nitride (AlN)/scandium aluminum nitride (ScAlN)-based surface acoustic wave (SAW) devices have a high Q-value, good temperature drift characteristics, and the ability to be compatible with CMOS, they have become some of the preferred devices for wireless passive temperature measurement. This paper presents the development of AlN/ScAlN SAW-based temperature sensors. Three methods were used to characterize the temperature characteristics of a thin-film SAW resonator, including direct measurement by GSG probe station, and indirect measurement by oscillation circuit and antenna. The temperature characteristics of the three methods in the range of 30–100 °C were studied. The experimental results show that the sensitivities obtained with the three schemes were −28.9 ppm/K, −33.6 ppm/K, and −29.3 ppm/K. The temperature sensor using the direct measurement method had the best linearity, with a value of 0.0019%, and highest accuracy at ±0.70 °C. Although there were differences in performance, the characteristics of the three SAW temperature sensors make them suitable for sensing in various complex environments.

Laser induced high temperature thermal-mechanical-oxygen coupling experimental system and method

In this paper, a thermal–mechanical–oxidation coupling experimental system based on laser heating is developed, containing two modes of Gaussian and flat-top lasers, which has a series of advantages such as high temperature range, rapid heating rate, and convenient observation. The system adopts active illumination and an optical filter to solve the problem where it is difficult for traditional digital-image correlation technology to image clearly under laser heating. A biaxial mechanical test machine is used to simulate the complex load by applying biaxial tension or compression loads on the material. Combined with the radiation temperature measurement and controllable flow field device, the thermal-mechanical-oxygen coupling experiment of high temperature resistant materials under aerobic environment can be carried out. The maximum uniform heat flux output density is 27.2 kW/cm2, and the maximum Gaussian heat flux output density is 105 kW/cm2. The thermal-mechanical-oxygen coupling experimental system and method are of great significance to the development of new high temperature resistant materials and thermal barrier coatings.

Fabrication and Investigation of Graphite-Flake-Composite-Based Non-Invasive Flex Multi-Functional Force, Acceleration, and Thermal Sensor.

This work examines the physics of a non-invasive multi-functional elastic thin-film graphite flake-isoprene sulfone composite sensor. The strain design and electrical characterization of the stretching force, acceleration, and temperature were performed. The rub-in technique was used to fabricate graphite flakes and isoprene sulfone into sensors, which were then analyzed for their morphology using methods such as SEM, AFM, X-ray diffraction, and Fourier transform infrared spectroscopy to examine the device's surface and structure. Sensor impedance was measured from DC to 200 kHz at up to 20 gf, 20 m/s2, and 26-60 °C. Sensor resistance and impedance to stretching force and acceleration at DC and 200 Hz rose 2.4- and 2.6-fold and 2.01- and 2.06-fold, respectively. Temperature-measuring devices demonstrated 2.65- and 2.8-fold decreases in resistance and impedance at DC and 200 kHz, respectively. First, altering the graphite flake composite particle spacing may modify electronic parameters in the suggested multi-functional sensors under stress and acceleration. Second, the temperature impacts particle and isoprene sulfone properties. Due to their fabrication using an inexpensive deposition technique, these devices are environmentally friendly, are simple to build, and may be used in university research in international poverty-line nations. In scientific laboratories, such devices can be used to teach students how various materials respond to varying environmental circumstances. They may also monitor individuals undergoing physiotherapy and vibrating surfaces in a controlled setting to prevent public health risks.

Design and Implementation of a Multi-Channel Temperature Measurement System Based on LabVIEW

As computer technology and instrument technology advance rapidly, both virtual instrument and Lab-VIEW have significantly grown. LabVIEW is extensively employed in the industrial and academic sectors for developing data acquisition systems, instrument control software, and analysis software. This paper presents the design of a multi-channel temperature measurement system based on a single-chip CPU and LabVIEW. The system consists of analog-to-digital conversion modules, temperature measurement modules, and data acquisition modules. The system uses the Nyquist-Shannon sampling theorem and the advantages of various digital filter types to obtain temperature uncertainty, including the compensation uncertainty of the reference junction. The system is of high quality in measuring accuracy, stability, scalability and other aspects. The complete system was inspected and verified using a superconducting magnetic energy storage device (SMES). The results demonized the ease of construction, practicality and precise regulation of the system. These results also show that temperature measurement devices are less than 0.1°C absolute error and are highly accurate, making them valuable for applications that require precise temperature measurements.

A Liquid Metal Temperature Detection System Based on Multi-Node Sapphire Fiber Sensor.

In order to accurately detect the temperature of molten aluminum and overcome the adverse influence of high temperature and corrosiveness on the sensing results, a temperature detection system based on a multi-node sapphire fiber sensor was proposed and developed. Through the structural parameter design of the fiber sensor, the scheme of utilizing the 0.7 mm diameter fiber and 0.5 mm groove was formulated. Simulation and analysis were carried out to determine the ultrasonic response distribution of the signal passing through the whole fiber sensor. The results indicate that the system is capable of distinguishing test signals from various positions and temperatures. Following the completion of the static calibration, the temperature of the molten aluminum was observed in real-time, and the data of the temperature measurements conducted at the two groove locations were compared. According to the obtained results, the test accuracy was greater than 1 degree Celsius and the temperature test stability was good, laying a solid foundation for the potential development of temperature measurement devices.

Research on a Wireless Temperature Measuring Device Using Inductive Power

With the advancement of urban construction, more and more distribution network lines are changed from overhead lines to cable lines. Currently, the distribution network cable connection generally adopts the European or American cable elbow. If the temperature changes inside the cable elbow can be monitored in time, it will help to find the hidden fault of the cable elbow in time and improve the safe operation level of the power grid. In this paper, the online temperature measurement device of distribution network cable is discussed and researched, and a contact-type inductive wireless temperature measurement sensor suitable for the elbow joint of distribution network cable is designed. The sensor not only can accurately measure temperature, but also has the characteristics of a convenient communication network, safe and reliable information, and strong insulation ability, which is suitable for large-scale promotion and application.

Design of Temperature Measuring Device in Student Dormitory Based on MSP430

Aiming at the phenomenon that the temperature of each dormitory is different in winter due to many factors in the dormitory of northern colleges and universities, this paper puts forward a simple and convenient dormitory temperature measurement device. The device takes an MSP430 single chip microcomputer as the control core, collects ambient temperature data through temperature sensor DS18B20, collects battery voltage with AD, and displays the collected battery voltage and ambient temperature through an OLED display screen. At the same time, according to the temperature measured by the temperature sensor, the device can output PWM to control the speed of the motor and simulate the intelligent temperature control fan. The experimental data shows that the device has high accuracy, is easy to use, and is easy to implement.

Optical filter-fiber combination based infrared measurement device for surface temperature measurement.

Neutral Beam Injection (NBI) is one of the four efficient ways of assistant heating on the Experimental Advanced Superconducting Tokamak (EAST) device. Measures have been taken to ensure more reliable monitoring of NBI components' thermal data. Infrared thermometers, unlike surface-mounted thermocouples, have the advantage of non-contact and thus will not cause interference and get far less chance of malfunctioning [Childs etal., Rev Sci. Instruments 71, 2959-2978 (2000)]. In this paper, the remote infrared temperature measurement with optical fiber is reported to meet the requirement of the EAST-NBI diagnostic system. Some tests have been conducted on the remote infrared temperature measurement under the working condition, and an atmospheric propagation simulation was performed to estimate the atmosphere absorption. The results indicate that the detector's response is in line with the theory, and the atmosphere absorption within a certain wavelength should not be ignored. Temperature measurement error is within one percent at temperatures above 200 °C. So, for the temperature range of 200-600 °C, the remote infrared temperature measurement by the optical fiber can fully meet its expectation.

A rapid prediction algorithm suitable to portable device for animal body-temperature measurement

The body-temperature is the most significant vital signs of human and animals. It is easily imaginable that measurement of body-temperature of animals will be much more difficult than that of human being due to lack of endurance or fear of measuring instrument. Infrared temperature measurement device may be a solution, however coverage of hair and fur may incur a large error. To address this issue, a rapidly executed algorithm is developed for prediction of steady state body temperature, which needs only a few one-tenth of measurement duration that the currently popular machine learning-based approach usually requires. Let a cubic function c⁢(t) fit the sampled temperature data which are generated by the measurement within a significantly short duration from tn-k to tn,k>0. Then let a quadratic function f⁢(t)=a2⁢t2+a2⁢t+a as a prediction function go through the point (tn,c⁢(tn)) and share the same slope of sn thereat. Finally try to find a next point (tn+m,f⁢(tn+m)), m>0, where the slope satisfies sn+m=sn/2 and m depends strongly on sn through an empirical formula. Accordingly, f⁢(t) can be determined by (tn,c⁢(tn)), sn and sn+m. Experiments indicate that the maximum of f⁢(t) approaches well the steady state temperature of the measured subject with a quite small error.

Feasibility and Error Analysis of Using Fiber Optic Temperature Measurement Device to Evaluate the Electromagnetic Safety of Hot Bridge Wire EEDs.

Most studies assessing the safety of hot bridge wire EEDs employ temperature sensors that directly use the measurements of the temperature measurement device without analyzing the accuracy of the temperature measurement. This study establishes the response function of the exposed bridge and exposed bridge temperature rise system of hot bridge wire EEDs through the Rosenthal’s temperature rise equation and Laplace transformation as well as experimental tests, and through the response function, the response law and numerical characteristics of the two are compared and analyzed under four typical excitations. Under steady current injection and continuous-wave radiation, both exposed bridge and exposed bridge temperature measurement systems can reach thermal equilibrium, and the equilibrium temperature of both are the same. However, under pulse excitation, the temperature rise measurement value is significantly different from the actual value due to the large difference in response time of the exposed bridge (1 ms) and the exposed bridge temperature measurement device (0.82 s). Studies have shown that under steady current injection and continuous-wave radiation, temperature rise measurements can be directly applied to the safety assessment of hot bridge wire EEDs, while under pulsed conditions, temperature rise measurements cannot be directly applied.