Explore the vast range of titles available.

18 highly instrumented timber-lined compartment fire experiments were conducted and their energy terms measured. The relative magnitude of the energy terms agreed well with literature. A simple set of relationships were developed to allow estimation of the energy terms based on a single characteristic compartment temperature from thermocouples within the compartment. The results showed a high level of agreement – particularly for estimating convective and conductive losses during the fully involved and decay phase. The agreement was less good for estimating the heat released rate for burning timber. The approach presented in this paper, suggests that key data about the energy terms from a timber lined compartment can be estimated from a relatively small number of instruments.

Accurate exhaust gas temperature (EGT) measurements are vital in the design and development process of internal combustion engines (ICEs). The unsteady ICE exhaust flow and thermal inertia of commonly used sheathed thermocouples and resistance thermometers require high bandwidth EGT pulse measurements for accurate cycle-resolved and mean EGTs. The EGT pulse measurement challenge is typically addressed using exposed thin-wire resistance thermometers or thermocouples. The sensor robustness to response tradeoff limits ICE tests to short durations over a few exhaust conditions. Larger diameter multiwire thermocouples using response compensation potentially overcomes the tradeoff. However, the literature commonly adopts weaker slack wire designs despite indications of coated weld taut wires being robust. This study experimentally evaluates the thin-wire thermocouple design placed in the exhaust of a heavy-duty diesel engine over wide-ranging exhaust conditions for improving both sensor robustness and accuracy of the measured EGT. The assessed design parameters included the wire diameter (51 μm to 254 μm), the exposed wire length, and the wires placed slack or taut with coated weld faces. All taut wires with ceramic-coated weld faces endured over 3 h of engine operation, while similar diameter slack wires (51 μm and 76 μm) were sensitive to the exhaust condition and exposed wire length. Reducing the wire diameter from 76 μm to 51 μm significantly impacted response improvements as evidenced at certain test conditions by a peak-peak EGT increase of 92 °C, a mean EGT drop of 26 °C, and a doubling of the sensitivity of mean EGT cycle-to-cycle variations to ±12 °C. Increasing the exposed wire length showed less significant response improvements. The Type-K thin-wire thermocouples showed negligible drift, thereby indicating the possibility of using smaller and longer wires built taut with coated weld faces for improved accuracy of EGT measurements in ICEs.

Flexible temperature sensors have been extensively investigated due to their prospect of wide application in various flexible electronic products. However, most of the current flexible temperature sensors only work well in a narrow temperature range, with their application at high or low temperatures still being a big challenge. This work proposes a flexible thermocouple temperature sensor based on aerogel blanket substrate, the temperature-sensitive layer of which uses the screen-printing technology to prepare indium oxide and indium tin oxide. It has good temperature sensitivity, with the test sensitivity reaching 226.7 μ V °C −1 . Most importantly, it can work in a wide temperature range, from extremely low temperatures down to liquid nitrogen temperature to high temperatures up to 1200 °C, which is difficult to be achieved by other existing flexible temperature sensors. This temperature sensor has huge application potential in biomedicine, aerospace and other fields. Flexible temperature sensors for in-situ measurements in high-temperature environmental. Real-time temperature monitoring and fast response to temperature changes. Convenient and simple preparation process—screen-printing technology. Practical application and testing of sensors in extreme environments.

Fire testing for civil aircraft is a crucial component of aircraft safety assessment. The flame temperature of the burner directly impacts the accuracy of fire tests. This study focuses on the Sonic burner as the research subject. Using a movable thermocouple rake, the influence of test specimens on the flame temperature field distribution of the Sonic oil burner was investigated. The findings reveal that the closer the Sonic burner is to the conical barrel exit region, the greater the difference between the outer flame layer temperature and the centerline temperature. Furthermore, when a specimen is present, the flame under impingement conditions exhibits smaller vertical cross-section temperature differences in the region near the specimen compared to free stream conditions. As the measurement location approaches the conical barrel exit region, the flame temperature field increasingly resembles that of the free stream state. This research provides fundamental reference data for fire test studies based on the Sonic burner.

C-type thermocouples are widely used to measure rich combustions; however, the measured temperature, i.e., the thermocouple junction temperature, is not equal to the gas temperature. The junction temperature results from the junction energy balance, including radiation with environments, conduction with thermocouple wires, and convection with gas. A correction based on the junction energy conservation can derive the gas temperature from the measured temperature. Two C-type thermocouples are used to measure the core region of the standard flames with known gas velocity, composition, and temperature. By matching the CFD-simulated junction temperature with the measured temperature, the emissivity of the thermocouples is obtained. In the temperature range of 1190–1542 K, the emissivity of both thermocouples is close to 0.4. Since the junctions of the C-type thermocouple are large, the area ratios of the wire cross-section to the junction surface are small, and the wire conduction effect is minimal. CFD simulations show that the junction temperatures only decrease by 3.9 K and 8.1 K without wire conduction when the 0.5 mm and 1.0 mm thermocouples measure the Hencken flame with the temperature of 2023.5 K. With the CFD simulation of the measurement of the diffusion region of the Hencken flame, where a strong gas temperature gradient exists, the junction contacting status is judged for the 0.5 mm thermocouple. The simulated temperature of the welding point is consistent with the measured temperature, indicating no wire contact inside the junction.

Undergraduate students often struggle with Thermodynamics due to a lack of hands-on experience with the devices and sensors discussed in coursework. Traditional experimental setups—such as engine test benches and HVAC systems—are prohibitively expensive and maintenance-intensive, limiting student access and requiring large group work that can reduce individual engagement. To address this issue, we developed and implemented a cost-effective thermocouple calibration apparatus for use in undergraduate Thermodynamics laboratories. The equipment utilizes affordable, readily available components, enabling the creation of multiple identical setups within a constrained budget. This allows students to work in smaller groups, increasing interaction and individual learning opportunities. The apparatus supports instruction in key Thermodynamics concepts, including temperature measurement, sensible and latent heat, and the Seebeck effect. Results from implementation show improved student comprehension and engagement. This approach offers a scalable, practical solution for enhancing Thermodynamics education, with potential applications across engineering curricula seeking to improve experiential learning within limited resources.

To adapt to the development of flexible electronic technology and intelligent wearable devices, the demand for verifying flexible thin film thermocouples is becoming increasingly prominent. The physical meteorological deposition method is a commonly used key technology for flexible coating. The use of the physical meteorological deposition method to prepare flexible thin film thermocouples has the characteristics of low cost, high efficiency, and high reliability. By introducing the principle of physical meteorological deposition method for preparing flexible thin film thermocouples and conducting verification experiments, the maximum temperature deviation of the prepared flexible thermocouple thin film is ± 0.3 °C, which can meet the temperature measurement needs of daily flexible temperature measurement thin films.

This article studies the technology and method of using thin film thermocouples to measure the temperature of dimethyl silicone oil. Firstly, the importance of temperature monitoring in the manufacturing industry and the advantages of thin film thermocouples in high-precision temperature measurement were outlined. Subsequently, the temperature measurement mechanism of thin film thermocouples was elaborated, which converts temperature signals into potential signals for measurement based on the thermoelectric effect. In order to verify the performance of thin film thermocouples, this paper designed and built an experimental platform using four types of thin film thermocouples: J-type, K-type, E-type, and T-type. Dimethyl silicone oil was used as the heat transfer medium, heated by an alcohol lamp, and temperature and voltage data were recorded using an infrared thermometer and multimeter. The experimental results showed that all four types of thin film thermocouples exhibited good linear relationships during the heating and cooling processes, and their respective Seebeck coefficients were calculated, which were close to the national standard values, verifying the accuracy and reliability of the experimental platform. This study provides strong technical support for the performance evaluation and practical application of thin film thermocouples.

Advanced nuclear reactor systems require new technologies for heat transfer and system monitoring to achieve autonomous operations and improved performance. Additive manufacturing offers the design flexibility to allow in situ sensor embedment to realize new manufacturing techniques that can improve the smart manufacturing, real-time monitoring, and performance of these systems. This study focuses on experiments investigating the feasibility of in situ sensor embedment using directed energy deposition (DED). We embedded type K thermocouples into 316L stainless steel (SS) samples using two different configurations (e.g., exposed and embedded tips) and two designs, one with the sensor placed directly onto the substrate (e.g., flush to substrate) and the second using an additive manufacturing base. Embedded sensor samples are analyzed via in situ measurements and high-temperature performance validation tests at 350 and 900 ºC. Temperature performance results at both temperatures show good agreement with manufacturer specifications, proving that these sensors could still capture accurate temperature readings after experiencing the high-heat laser processing during DED fabrication. Additional optimization experiments were performed on the exposed tip configuration using a surrogate thermocouple to improve tolerances and the embedment process. These experiments lead to improved tolerances, lower porosity, smaller gaps between the sensor and base, and better junction contact for the sensor. Further optimization of this embedment strategy will improve the structural stability and tolerances within the component. This embedment strategy demonstrates a proof of feasibility for DED embedment with commercial sheathed thermocouples. Further investigations into fabrication strategies should be conducted to fully realize smart manufacturing and an advanced real-time monitoring system.

Efficient thermal management is critical for the performance, safety, and longevity of lithium-ion batteries, particularly in new energy vehicles. This paper presents the development and application of a NiCr/NiSi thin-film thermocouple fabricated via magnetron sputtering on a polyimide substrate, aiming to provide high-precision, fast-response internal temperature measurements for lithium-ion battery systems. The thermocouple demonstrates a Seebeck coefficient of approximately 40.95 μV/°C and a repeatability error of only 0.45%, making it highly suitable for capturing transient thermal events. The main innovation of this work lies in the comprehensive integration of simulation and experimental validation to optimize the thermocouple’s performance for lithium-ion battery applications. This includes static calibration, external short-circuit, and puncture tests, which collectively confirm the thermocouple’s reliability and accuracy. Additionally, the study explores the impact of ambient temperature variations on internal battery temperatures, revealing a nearly linear increase in internal temperature with rising ambient conditions. The findings offer valuable insights for improving battery thermal management systems, establishing early warning thresholds for thermal runaway, and enhancing the overall safety of lithium-ion battery applications.