Temperature Measurement System Research Articles

Wireless, multimodal sensors for continuous measurement of pressure, temperature, and hydration of patients in wheelchair

Individuals who are unable to walk independently spend most of the day in a wheelchair. This population is at high risk for developing pressure injuries caused by sitting. However, early diagnosis and prevention of these injuries still remain challenging. Herein, we introduce battery-free, wireless, multimodal sensors and a movable system for continuous measurement of pressure, temperature, and hydration at skin interfaces. The device design includes a crack-activated pressure sensor with nanoscale encapsulations for enhanced sensitivity, a temperature sensor for measuring skin temperature, and a galvanic skin response sensor for measuring skin hydration levels. The movable system enables power harvesting, and data communication to multiple wireless devices mounted at skin-cushion interfaces of wheelchair users over full body coverage. Experimental evaluations and numerical simulations of the devices, together with clinical trials for wheelchair patients, demonstrate the feasibility and stability of the sensor system for preventing pressure injuries caused by sitting.

Synchronous in-situ measurement for deformation and temperature fields with high spatial and temporal resolution under dynamic loading

Studying the dynamic failure of materials is crucial because this failure occurs extensively in mechanics and earthquake fields. However, obtaining the deformation and temperature fields in high-speed dynamic cases is challenging, particularly when analyzing the mechanics of thermo-mechanical coupling. This study developed a thermo-mechanical coupled in-situ measurement system to acquire synchronized information on the load, deformation and temperature fields during a specimen dynamic failure process with high temporal and spatial resolution. In particular, the deformation field was obtained using a high-speed camera connected to a microscope that could achieve a spatial resolution of 3.6–3.8μm/pixel and a temporal resolution of 1μs. Moreover, a 64 × 64 focal plane array infrared detector was developed to measure temperatures with the time resolution of 1μs. A Newtonian optical system was applied to achieve the infrared detector’s spatial resolution of 25μm. The temperature measurement system could measure temperatures ranging from 100 to 800 °C. The split-Hopkinson pressure bar was used as the dynamic loading device to realize the high strain rate loading of a Ti-6Al-4V hat-shaped specimen, verifying the deformation and temperature measurement capabilities. The results from the Ti-6Al-4V specimen under dynamic loading showed an evident adiabatic shear band and the temperature rise, suggesting that the experimental devices provided was an effective tool to study the thermo-mechanical response of materials under dynamic loading.

Noninvasive Deep-Tissue Temperature Monitoring Based on Magnetic Mediated Thermoacoustics

Noninvasive acquisition of deep tissue temperature has important applications in home health monitoring, hyperthermia safety control, and other domains. In this work, we present here a novel magnetically mediated thermoacoustic temperature measurement method. Utilizing coil to stimulate amplitude modulated magnetic field and ultrasound transducer to receive the generated thermoacoustic wave from the inserted magnetic nanoparticles. Benefiting from the high sensitivity of thermoacoustic emission from nanoparticles and the deep penetration capability of both magnetic field and ultrasound propagation, the proposed thermoacoustic temperature measurement system enables a high measurement accuracy of 0.5 degrees Celsius in real time. This work potentially facilitates further development of closed loop magnetic hyperthermia for practical clinical applications.

Real-time wireless temperature measurement system of infant incubator

The internet of things (IoT) has allowed for ubiquitous measurement. Infant incubator temperature is one of crucial parts that need to be measured, especially for the stability and uniformity temperature. Based on the interpretation of IEC 60601-2-19, we proposed measurement method using IoT with the message queue telemetry transport (MQTT). In the 10,000 packet, the result shows the quality of service (QoS) level 2 of the system has the highest delay, however it has the lowest packet loss data than the other QoS. For 1 hour, the uniformity result and stability can fulfill the standards. Uniformity of 32°C, the lowest difference is point C with 0.32 °C, and the highest difference is point B with 0.75 °C. Uniformity of 36 °C, the lowest difference is point B with 0.27 °C, and the highest difference is point C with 0.79 °C. The stability of 32 °C and 36 °C is 0.32 °C and 0.44 °C, respectively. Moreover, the Kruskal Wallis test shows the highest difference average from point M is point A and B. It occurred because of the point A and B located far from the heater part, so the point A and B colder than point C.

Flame and emission characteristics of preheated ammonia combustion based on chemical reaction network

Ammonia (NH3) is an ideal fuel for achieving decarbonisation in energy production and industrial combustion, but suffers from low flammability and high nitrogen oxides (NOx) emissions in combustion. Preheating of NH3 can lead to stable combustion of NH3 and reduce nitric oxide (NO) emissions. In this study, the special combustion characteristics of the fuel preheated flame were investigated. Combustion, optical temperature measurement and gas measurement systems were set up. The flame images were captured and the flame temperature distribution was reconstructed by experiment. The temperature field in the longitudinal profile at the flame centre was divided into 11 temperature regions. Computational fluid dynamics (CFD) was carried out on the preheated NH3 combustion to analyse the distributions of components and velocity vectors. Then, a chemical reaction network (CRN) with 10 perfectly stirred reactors (PSR) was constructed based on the temperature field reconstructed by experiment and the distributions of components and velocity vector by CFD simulation. The temperature, the concentration of products and reactants, intermediate product components and reaction pathways were analysed by the CRN method to investigate the jet combustion characteristics of preheated NH3 combustion. Experimental and CFD simulation results showed that differently coloured regions appeared in the upstream of the pure NH3 flame, and the high-temperature region was widely distributed in the temperature field. CRN simulation results showed that the formation of special flame characteristics was associated with the generation of large amounts of hydrogen (H2) and water (H2O), and the reactions of NH2 with NH2 were the most dominant generating pathway of H2. Reaction pathway analysis of NH3 showed that H and OH radicals were most relevant to the production of NO, while NH2 radicals were most relevant to the consumption of NO in preheated NH3 combustion.

Conceptual Model, Experiment and Numerical Simulation of Diaphragm Wall Leakage Detection Using Distributed Optical Fiber.

Leakage in the diaphragm wall is difficult to detect in deep foundation pits. In this study, the conceptual model of active and passive thermal leak detection methods was proposed according to the occurrence of temperature field anomalies caused by seepage. Experiments were performed using a heating system and an optical fiber temperature measurement system to verify the thermal leakage detection systems. Numerical simulations were performed to understand the mechanism of the detecting method. Results indicated that the optical cable could detect the low-temperature anomaly in the active temperature field leak detection. The arrangement method of the leakage detection system was also presented in actual engineering.

Kitten Temperature Monitoring System Using Blynk IoT Application-Based Thermal Camera

Kitten Temperature Monitoring System Using a Thermal Camera with the IoT-Based Blynk Application is intended for kitten caregivers to be able to monitor in real time via a smartphone. An incubator is valuable when a kitten cannot maintain its body temperature within the normal range. The temperature measurement system uses the AMG8833 thermal camera, which can detect a kitten’s temperature based on the optimal distance (5-15 cm). Each detected temperature result will be displayed in digital form on the LCD20x4. The test was carried out by comparing the temperature detection performance of the AMG8833 thermal camera system that was tested with a standard infrared IR sensor. The test results show that this system has a difference between the AMG8833 thermal camera system tested and the standard IR sensor of 3.5 oC.

A Novel System for Ocular Surface Temperature Measurement and Tracking

A Novel System for Ocular Surface Temperature Measurement and Tracking

High-Resolution Photonic Temperature Measurement System Based on Frequency Locking of Microring Resonator

High-Resolution Photonic Temperature Measurement System Based on Frequency Locking of Microring Resonator

Proposal of a Skin Temperature Measurement System Based on Digital Thermometers

The representation of temperature measurement methods is worldwide, as is the number of industries that use them. Their utilization allows one to assess the object’s temperature relatively accurately and further according to the defined dependencies to evaluate its condition. In the medical sector, non-invasive temperature measurement methods are increasingly gaining ground. In our work, we focus on the design of a system for measuring skin temperature using digital DS18B20 thermometers. The technical design consists of the mechanical design of the sensor housing based on the requirements of healthcare professionals, the design of a 1-wire bus active pull-up driver with improved features, and the user software, allowing for the future implementation in various, not necessarily medical environments. The main contribution lies in optimizing the hardware design concerning the components’ parameters and surge protection. In the medical field, the aim was to compare changes in skin temperature in the shoulder region depending on the type of muscle contraction during static and dynamic components of movement and to record the thermal work of the muscle during activity in real-time. We experimented by applying temperature sensors to the deltoid muscle of the dominant limb in a temperature environment of 25.76 °C. In the experimental measurements, we demonstrated that during the three selected muscle work movements, there was a temperature change in the respective regions of the deltoid muscle for each of the three, which the temperature sensors could capture. Our results were statistically significant when comparing the baseline values, and the highest temperature reached. The level of significance α ⩽ 0.05 and a low percentage of errors were valid.

Flame and emission characteristics from NH3/CH4 combustion under ultrasonic excitation

As a high energy density hydrogen-rich carrier, ammonia (NH3) is a highly promising carbon-free fuel. The large-scale industrial application of NH3 is limited by its low reactivity and high NOx emission. In this work, the flame and emission characteristics of ammonia/methane (NH3/CH4) non-premixed combustion were investigated under ultrasonic excitation. An experimental system was designed and built, including non-premixed combustion system, loading ultrasonic system, deflectionmography temperature measurement system and flue gas measurement system. Combustion and measurement experiments at different ultrasonic frequencies and NH3/CH4 blending ratios were carried out. Flame images and flue gas species concentrations under ultrasonic excitation were acquired. The 3-D temperature field was reconstructed. The influence of ultrasonic excitation at different frequencies on flame characteristics, flame temperature field and emission characteristics of the combustion process was analysed. The mechanism of NH3/CH4 combustion enhancement and emission reduction was revealed when the flame was ex-cited by ultrasonic waves. Results showed that part of the hydrocarbon fuels was replaced by NH3 to reduce CO2 emission. The height and color of the NH3/CH4 flame were changed and the high temperature area of the flame gradually expanded as ultrasonic acted on the flame. As ultrasonic frequency increased, the emission concentrations of unburned CH4, unburned NH3, and NO decreased significantly. The flame was ex-cited by ultrasonic waves, which reduced its local equivalent ratio, improved combustion efficiency and suppressed NOx generation.

Online Measurement Method of Molten Iron Temperature After Blast Furnace Skimmer Based on Infrared Vision

The online measurement of molten iron temperature in blast furnace ironmaking process is an urgent need in the ironmaking industry, but under the influence of factors such as overflowing slag and dust, the online measurement of molten iron temperature based on infrared temperature measurement faces the problem of low measurement accuracy. Aiming at the interference of overflowing slag and dust, this paper proposes a method for online measurement of molten iron temperature after skimmer based on infrared vision. Firstly, an industrial-grade infrared visual temperature measurement system is designed to obtain infrared images of molten iron for a long time and stably after skimmer. Secondly, ShuffleNet v2 is used to identify the slag and dust interference states of molten iron after skimmer, and then the molten iron temperature mapping model during slag overflowing and the molten iron temperature compensation model during dust disturbance are established. Finally, the online accurate molten iron temperature (MIT) after skimmer is obtained. The temperature measurement experiment on the blast furnace site shows that the method can accurately obtain the MIT after skimmer online.

Application of Passive Time-to-Pulse Converter in Temperature Measurement Systems of Moving Objects

A variant of the implementation of a time-to-pulse converter as part of a human temperature measurement system is considered, in which a first-order circuit forming an information time interval is formed by a resistance temperature device and a capacitor. Initialization and registration of the time for the transient phenomena are carried out by MIS transistor and an integral comparator. Assessment of the differential sensibility of the converter depending on the time constant of the forming circuit for medium-speed keys is provided. The scheme of a multichannel converter is presented, with sequential and cyclic resistance of several thermal converters into the duration of the impulse response. At the same time, to decrypt the number of the measuring channel, the conversion cycles are separated by pauses. The function of converting temperature into the duration of the time interval is derived for a nickel resistance temperature device based on an equivalent electrical circuit of a time-to-pulse converter. Analytic forms are obtained to assess the effect of inaccuracy of circuit elements and destabilizing factors on the temperature measurement error. The conditions for its reduction have been determined. The converter connection is investigated in the Micro-Cap circuit simulation environment. The discrepancies between the experimental and calculated values of the conversion function did not exceed 0.2%. The temperature instability of the output information intervals of the time-to-pulse converter was no more than 0.1% in the operating temperature range 0 ...50°C and is due to the voltage temperature drift of the comparator bias voltage. The use of a passive time-to-pulse converter is advisable in telemetry systems for measuring temperature or other physical quantities with primary resistance, capacitance or inductance converters forming a first-order circuit in the conversion path. The presented analytical expressions can be used to estimate the additional measurement error.

Phone-based Ambient Temperature Measurement with a New Confidence-based Truth Inference Model

Monitoring the indoor temperature can help saving of energy and improve the comfort level. Smartphone, as a ubiquitous device, can be an additional data source to provide the ambient temperature estimation. However, the estimation results sometimes can be unreliable due to the different phone using states. How to integrate multiple estimation results in one area to get a more accurate prediction result is still a challenge. In this work, we proposed one phone-based ambient temperature measurement system which contains two models. The first temperature prediction model takes easily accessible phone state features as inputs and outputs ambient temperature prediction with a confidence value. The second truth inference model takes multiple prediction results with confidences as inputs and outputs a referred final prediction result. Our temperature prediction model reaches 0.253°C with MAE in our testing set. We also proved by transfer learning our model can be used in other new type of phones. We evaluate the truth inference model in our testing dataset and it reaches 0.128°C, which outperforms the state-of-the-art truth inference algorithms. We believe this work can contribute to energy conservation and provide new ideas for crowdsourcing.

Study and Design of a Multi-range Programmable Sensor for Temperature Measurement

In this paper, a wide-range high-precision sensor has been designed in order to accurately measure the temperature in a medium with arbitrary temperature variation and the implementation of a wide-spectrum temperature measurement system with a self-selected multi-sensor has been realized. This multi-sensor core is made up of different sensors combined to measure different temperature ranges. This concept can be used for high-precision temperature measurement in electrical capacitance tomography applications. The proposed technique is well suited for temperatures in boilers, industries, and everywhere high temperature measurement sensitivity is needed by using different combined temperature sensors of high precision.

High Temperature Measurement with Low Cost, VCSEL-Based, Interrogation System Using Femtosecond Bragg Gratings.

In this article, a cost-effective and fast interrogating system for wide temperature measurement with Fiber Bragg Gratings is presented. The system consists of a Vertical Cavity Surface Emitting Laser (VCSEL) with a High Contrast Grating (HCG)-based cavity that allows for the fast tuning of the output wavelength. The work focuses on methods of bypassing the limitations of the used VCSEL laser, especially its relatively narrow tuning range. Moreover, an error analysis is provided by means of the VCSEL temperature instability and its influence on the system performance. A simple proof of concept of the measurement system is shown, where two femtosecond Bragg gratings were used to measure temperature in the range of 25 to 800 °C. In addition, an exemplary simulation of a system with sapphire Bragg gratings is provided, where we propose multiplexation in the wavelength and reflectance domains. The presented concept can be further used to measure a wide range of temperatures with scanning frequencies up to hundreds of kHz.

Application of Passive Wireless Temperature Online Monitoring System Based on Internet of Things Technology in Substation

With the improvement of the automation level of the power system, the number of operation and maintenance personnel continues to decrease, but the use of switchgear is quite large. Since the switchgear is a metal armoured device with a closed shell, the hot spots inside the switchgear cannot be detected in time during operation. Effective temperature measurement and the safety of equipment cannot be effectively guaranteed. In order to avoid the aging caused by the excessive current load of the switch cabinet, poor contact of cable joints and contacts, or long-term operation, which will cause heat in the place, forming a vicious circle and eventually leading to insulation breakdown or fire accidents, Establish a wireless temperature measurement system for switch cabinets to monitor the temperature of the parts where the equipment is prone to overheat, and issue an alarm message when the temperature rises abnormally. At present, the manual inspection of switch cabinets in the power supply system cannot effectively and timely detect fire hazards, so the problem of online monitoring of switch cabinet temperature is particularly prominent. Using the Internet of Things sensing technology and communication technology, build an Internet of Things-based electrical connection point temperature online monitoring system, the all-weather real-time monitoring of the connection parts of high-voltage electrical equipment can effectively reduce the equipment failure rate, promote the condition maintenance of power equipment, and ensure the safe and economical operation of the power system.

Temperature‐Sensitive Colored Radiative Cooling Materials with Efficient Cooling Performance

Several daytime radiative cooling materials involving various structures and composed using multilayer thin films, polymers, and nanoparticles have been fabricated and studied. However, their surface is of white or some other monotonous color because of the requirement for most of the incident sunlight to be reflected. A temperature‐sensitive colored radiative cooling (TCRC) material that provides efficient cooling while preserving the aesthetic properties of the surface has been developed. The TCRC material is manufactured as a bilayer structure for efferent cooling applied on a colored radiative cooling emitter. The bottom layer reflects as much light as possible using polyvinylidene fluoride and alumina particles, and the top layer uses a thermochromic color pigment to display color. The optical properties of the TCRC material, in response to temperature changes, are evaluated and its efficient cooling ability is confirmed. The temperature cooling is confirmed for TCRC emitters of yellow, magenta, and blue colors, using an outdoor temperature measurement system, and it is experimentally confirmed that the TCRC emitters provide more cooling (by 1.75, 2.67, and 4.31 °C, respectively) than conventional paint of the same color.

Assessment of laser cutting parameters and heat-affected zone on microstructure and fatigue behaviour of carbon fibre-reinforced epoxy

In this study, the effects of laser cutting on the fatigue properties of carbon fibre-reinforced polymers are investigated. For this purpose, unidirectional carbon fibre-reinforced epoxy laminate is cut by laser. The material to be cut evaporates directly in the laser beam and the laser beam can produce thermally induced damage, which is referred to as heat-affected zones. Specimens are cut with two different parameters (varying cutting velocity and break time between passes) to widths up to 15 mm for investigation of the heat-affected zones effects on fatigue behaviour. Prior to fatigue tests microstructure is evaluated using light and scanning electron microscopy with regard to cutting geometry and heat-affected zones. Fatigue tests are performed using multiple amplitude tests with a stress ratio of 0.1, instrumented with a video extensometer system and thermocouples for strain and temperature measurements to determine the influence on mechanical properties and evaluate the sensitivity of the used testing method and measurement instrumentation for this use case. Lower cutting velocities and break time passes lead to a larger edge angle and thus in different specimen widths on front (laser inlet) and bottom (laser outlet) of the carbon fibre-reinforced epoxy laminate. Therefore, the resulting true geometry was considered using statistical approaches to eliminate possible cross-sectional errors regarding mechanical stress application. The results show that the specimen widths and process parameters impact the fatigue properties, highlighting the importance of knowledge about heat induction and the detection of inflicted laminate damage.

Modeling and Application of Temporal Correlation of Grain Temperature during Grain Storage

Temperature measurement system malfunction and sensor failure in grain storage warehouses can lead to missing grain temperature data on some days. Missing data is not conducive to the monitoring of grain storage conditions. This paper establishes mathematical models of temporal correlation coefficients of grain temperature and storage time in different planes, and analyzes the influence of storage state change on grain temperature correlation. The historical grain situation data for about one year were selected from 27 flat grain storage warehouses distributed in the second to seventh grain storage ecological zones in China. In addition, correlation coefficients of grain temperature were then calculated on the XOY, XOZ and YOZ planes of each warehouse. During this process, the time interval included 1, 7, 14, 21, 28, 35, 42, 49, 56, 63 and 70 days, meaning that the correlation coefficients between the grain temperature on the day and the grain temperature after storage for 1, 7, 14, 21, 28, 35, 42, 49, 56, 63 and 70 days were calculated. Next, the correlation coefficients from the same time intervals and planes in each warehouse were sequentially connected to form arrays of correlation coefficients. Then, the 3σ-threshold setting methods and DBSCAN (density-based spatial clustering of applications with noise) method were used to analyze the correlation coefficients those arrays. According to the results, we set the correlation coefficient thresholds for each plane (XOY, XOZ and YOZ planes) at each time interval. The models were then established regarding the correlation coefficient thresholds and storage time intervals. Subsequently, the sum of squares for error (SSE), coefficient of determination (R2), and root mean square error (RMSE) were chosen to evaluate the models, with the results showing that the effect of the model established by the threshold set by the 3σ-setting method, with SSE, R2 and RMSE of 0.056, 0.9771 and 0.0748, respectively, was better than the model established using the DBSCAN method. Finally, the correlation coefficients of grain temperatures with empty warehouse, new grain addition, aeration and self-heating were analyzed. The results show that the four modes in a certain time interval (e.g., 30 days) does not meet the correlation coefficient threshold during normal storage. The result can provide a theoretical basis for grain storage condition detection when grain temperature data is intermittently missing.