Sensor For Measurement Of Temperature Research Articles

Calibration of a High-Resolution Slow-Light Fiber-Bragg-Grating Sensor for Temperature Measurements of Laser-Cooled Fibers

Calibration of a High-Resolution Slow-Light Fiber-Bragg-Grating Sensor for Temperature Measurements of Laser-Cooled Fibers

Hardware Testing Methodologies for Wide Bandgap High-Power Converters

Wide bandgap (WBG) power semiconductor devices are increasingly replacing silicon IGBTs in high-power and high-voltage power electronics applications. However, there is a significant gap in the literature regarding efficient testing methodologies for high-power and high-voltage converters under constrained laboratory resources. This paper addresses this gap by presenting comprehensive, hardware-focused testing methodologies for high-power and high-voltage WBG power semiconductor-based converter bring-up before the control validation phase steps in. The proposed methods enable thorough evaluation and validation of converter hardware, including device switching characteristics, driving circuit functionality, thermal management performance, insulation integrity, and sustained operation at full power. We utilized the double pulse test (DPT) to characterize switching performance in a two-level phase leg configuration, extract circuit parasitics, and validate magnetic components. The DPT was further applied to optimize gate driving circuits, validate overcurrent protection mechanisms, and measure device on-resistance. Additionally, a multicycle test was introduced to rapidly assess steady-state converter performance and estimate efficiency. Recognizing the critical role of thermal management in high-power converters, our methodologies extend to the experimental extraction of key thermal parameters—such as junction-to-ambient thermal resistance and thermal capacitance—via a heat loss injection method. A correlation method between temperature sensor measurements and junction temperature is presented to enhance the accuracy of device temperature monitoring during tests. To ensure reliability and safety, dielectric withstand tests and partial discharge measurements were conducted at both component and converter levels under conventional 60 Hz sinusoidal and high-frequency PWM waveforms. Finally, we highlight the importance of testing converters under full voltage, current, and thermal conditions through power circulating tests with minimal power consumption, applicable to both non-isolated and isolated high-power converters. Practical examples are provided to demonstrate the effectiveness and applicability of these hardware testing methodologies.

Highly sensitive one-dimensional Dielectric-Superconductor photonic crystal structure for low temperature sensing applications

The work proposed in this paper investigates the design and simulation of low temperature refractive-index (RI) sensor using one-dimensional photonic crystal (1D-PhC) structure. The bilayer stack is created using dielectric and superconductor materials. The dielectric material is assumed to be air and the superconductor considered is YaBa2Cu3O7. Compared to superconductor material, air’s RI is hardly affected by the temperature. The parameter perceived by the suggested sensor for precise temperature measurement in the region of 10 K to 90 K is thought to be the superconductor’s RI, which is a function of temperature. To the best of our knowledge, the structural characteristics have been precisely adjusted to increase sensor efficiency to a level never before seen in published research. According to the findings, the temperature sensitivity of 1.524 nm/K and the maximum RI sensitivity of 1079.42 nm/RIU are found in the proposed structure. Applications for bio-sensing are a good fit for the suggested sensing device.

Development of a single-ended mid-infrared fiber-coupled laser absorption sensor for measurements of temperature, CO, and CO2 in harsh environments

The design and application of a single-ended mid-infrared fiber-coupled laser absorption spectroscopy sensor for acquiring measurements of temperature, CO, and CO2 via time-multiplexed wavelength-modulation spectroscopy (TM-WMS) are presented. This sensor utilizes an indium trifluoride (InF3) fiber bundle with six large multi-mode (MM) catch fibers surrounding one smaller single-mode pitch fiber and a custom optics housing to collect laser light that is back-scattered off native surfaces. The fraction of light collected by the sensor was evaluated for targets made of common materials used in combustion applications (i.e., aluminum, steel, and copper). The sensor was demonstrated with 1 kHz measurements of temperature, CO, and CO2 in steady and unsteady propane-air flames with a target standoff distance of 3 cm.

Wideband CPW fed four port MIMO antenna based microwave sensor for deep brain temperature measurement

This study presents a wideband CPW fed four-port multi-input multi-output (MIMO) antenna-based microwave sensor for measuring deep brain temperature inside human head. The range of frequency is from 5.45 to 8.56 GHz at the resonance frequency of 7.25 GHz. Coplanar Waveguide (CPW) fed approach on a low-cost FR4 substrate is used in designing the planar antenna. The presented antenna is compact, having overall dimensions of 40 × 40 × 1.6 mm3. In the operational frequency range, the obtained diversity performance for MIMO antenna shows Envelope Correlation Coefficient (ECC) < 0.05, Diversity Gain > 9.95, total active reflection coefficient (TARC ) < −13 dB and channel capacity loss (CCL) < 0.125 bits/S/Hz. For deep brain temperature measurements, the proposed sensor provides electric field of 3.92 V m−1 and specific absorption rate (SAR) value of 0.16 W kg−1 at the 9 mm distance inside the human head Phantom. The proposed sensor is capable of measuring 0.1 °C change in temperature at 10 W of input power for 60 s when all four ports are active.

Application of Cr-N and Fe-Pd Thin Films to Tactile Sensors for Simultaneous Strain and Temperature Measurement

Application of Cr-N and Fe-Pd Thin Films to Tactile Sensors for Simultaneous Strain and Temperature Measurement

Smoothing of the Noisy Lithium-ion Battery Surface Temperature Data Based on Savitzky–Golay (SG) Filter

As the charging current and surrounding temperatures rise concurrently in an electric vehicle's (EV) battery pack, the battery temperature increases abruptly beyond safe limits. The battery is susceptible to triggering thermal runaway at higher temperatures, leading to battery damage and even an explosion. The control system depends on these measurement data from the sensors to prevent dangerous situations and maximize the performance and cycle life of batteries. However, traditional noisy temperature measurement sensors in a real application, such as thermistors and thermocouples, are extensively used. In this paper, the experimental setup, the heat pipe-based battery thermal management system (BTMS) was designed and experimented with high input power. The battery was sandwiched with heat pipes, and heated at 30, 40, 50, and 60 W. The Savitzky-Golay filter technique is applied to the noisy temperature data of the surface temperature of the lithium-ion batteries (LIBs) used to estimate the condition of the battery. According to this study, the start-up time parameter in battery thermal management can be controlled by the Savitzky-Golay filter. This will attenuate random temperature fluctuations of battery temperature noise and avoid the cooling system from being falsely triggered. The results are measured by the signal-to-noise (SNR) to demonstrate the ability of the Savitzky-Golay filter to eliminate noise

Investigation on FBG based optical sensor for pressure and temperature measurement in civil application

Investigation on FBG based optical sensor for pressure and temperature measurement in civil application

Development and Validation of a Mathematical Model for Pyroelectric Temperature Measurement Sensors for Application in Mobile Robotic Systems

A pyroelectric temperature sensor for measuring human body temperature with increased accuracy and speed for application in mobile robotic systems has been developed. This pyroelectric temperature sensor for measuring human body temperature is intended for use in various educational institutions. Its usage will allow for identifying sick or potentially ill people and providing them with preliminary advice and avoid infecting other people. This is particularly important considering the seasonality of dangerous infectious diseases and the emergence of new ones (e.g., COVID-19). It is also advisable to use this pyroelectric sensor in hospitals, where temperature measurement is very crucial for monitoring the course of various diseases. The proposed pyroelectric temperature sensor is based on a nonlinear oscillatory system, which provides high sensitivity and allows for solving the problem of increasing the accuracy of measuring the human body temperature in a non-contact way. Measurement error is ±0.1% in the operating range (32–43) °C, measurement time—1 s, and the frequency instability is 3·10−4.

PMF based Sagnac interferometric sensor for simultaneous measurement of strain, temperature, and torsion

We propose a Sagnac interferometric sensor for simultaneous strain, temperature, and torsion measurement based on a polarization-maintaining fiber (PMF). The Sagnac sensor consists of a single-mode fiber (SMF), PMF and SMF spliced sequentially to form an SMF-PMF-SMF structure. The designed Sagnac interferometric sensor exhibits different wavelength shifts for strain, temperature and torsion measurements. Therefore, we observed three selected dips in the interferogram and measured strain, temperature and torsion simultaneously by their wavelength shifts. The maximum sensitivity of the sensor to strain, temperature, and torsion were experimentally measured to be 28.9 pm/µε. (10-12 m), −1.7504 nm/°C, and −1.0964 nm/(rad/m), and the measurement ranges were 0∼720 με, 25 °C–39 °C, and −7.679 rad/m∼4.887 rad/m (−110°–70°), respectively. In the subsequent experiments, we also verified the feasibility of the sensor for simultaneous measurements, and the errors of the results obtained were less than 10%. And we have successfully increased the temperature measurement range to 25°C∼85°C by cascading FBG in the original structure. The designed sensor has the advantages of easy fabrication, high sensitivity, and bi-directional torsional measurement, which have a wide range of applications in the fields of structural health detection, industrial control, and aircraft attitude recognition.

Concatenated Bragg grating fiber-optic sensors for simultaneous measurement of curvature, temperature, and axial pressure

Abstract. This paper presents the development and evaluation of four sensors based on multiple fiber Bragg grating (FBG) constellations embedded in a silicon dioxide single-mode fiber (SMF) for simultaneous measurement of pressure, temperature, and bending curvature. We applied dimension and material variations – including core, cladding, and coating dimensions; coating material; and the number and arrangement of the FBGs – to optimize the reflected signal response and increase information density. A bootstrap-aggregated ensemble of decision trees was used to evaluate the sensor signal. The results show that adjusting the cladding-to-coating ratio led to significant improvements in pressure and bending prediction performance. Additionally, two combined FBGs were fabricated to form a fiber Bragg grating Fabry–Pérot interferometer, which enabled the detection of curvature with a root-mean-square error (RMSE) of 0.0034 L mm−1 (R2=1), axial pressure with an RMSE of 0.0564 bar (R2=0.99), and temperature with an RMSE of 0.0265 °C (R2=1). At the time of writing, there is no commercially available instrument that can perform these measurements simultaneously.

Study on the photoluminescence performance and thermal sensitivity of (Y,Gd)2O3:Tb3+,Dy3+,Tm3+ phosphors

Using ammonia as a precipitation agent, (Y,Gd)2O3:Tb3+x,Dy3+y,Tm3+z phosphors were synthesized by the co-precipitation method. In order to improve the luminescence performance of the luminescent center Tb3+, Tb3+-Dy3+ co-doping and Tb3+-Dy3+-Tm3+ tri-doping were successively carried out, and the optimal component formulations were determined by the controlled variable method (x = 0.03, y = 0.005, z = 0.001). XRD results showed that the sample has a cubic phase Y2O3 structure with good crystalline properties. SEM results revealed that the samples have a unique micro morphology of small ball aggregation. The effects of doping concentration of Dy3+ and Tm3+ on the luminescence properties of Tb3+ were systematically investigated. The energy transfer mechanism among the three ions of Tb3+-Dy3+-Tm3+ was demonstrated by photoluminescence spectroscopy, and the main interaction modes between ions were elucidated. In addition, the matrix lattice environment can change the thermal stability properties of phosphors. In this paper, the temperature characteristics of Y2O3:Tb3+,Dy3+,Tm3+ phosphors are expected to be changed by microtuning the Y2O3 matrix lattice with the introduction of Gd3+. The fluorescence intensity ratio (FIR) and thermal sensitivity indicated that Gd3+ has good temperature sensitivity, and its introduction can effectively improve the temperature sensing performance of the phosphors, which has a wide range of applications in optical temperature measurement sensors.

Live Data Monitoring in Industry

Abstract: In contemporary industrial environments, real-time monitoring of critical parameters is vital for ensuring safety, efficiency, and compliance with regulations. This thesis details the development and implementation of an advanced live data monitoring system designed to track temperature, humidity, fire presence, and oxygen levels. Key components of the system include a DHT sensor for temperature and humidity measurement, a fire sensor for fire detection, an oxygen sensor for monitoring atmospheric oxygen, and a buzzer for immediate auditory fire alerts. Central to the system is the ESP8266 WiFi module, which facilitates the wireless transmission of sensor data to ThingSpeak, a cloud-based data collection and visualization platform. This setup allows for continuous, remote monitoring of environmental conditions, providing critical insights and alerts to industrial operators. The project delves into the hardware configuration, sensor calibration, data acquisition processes, and wireless communication protocols essential for effective real-time monitoring. It also addresses the challenges of integrating multiple sensors and ensuring reliable data transmission in an industrial setting. The results demonstrate the system's capability to provide accurate, timely data, enhancing safety protocols and operational efficiency. By utilizing IoT technology, the proposed system offers a scalable solution for industrial environments aiming to implement advanced monitoring and alert systems. This work contributes to the field of industrial automation by illustrating a practical application of IoT in improving monitoring and safety measures, highlighting both the technical achievements and practical implications of the implemented system.

Development of a Low-Cost and Portable Device for Monitoring Heart Rate, Blood Oxygen Saturation, and Body Temperature in Infants Incubator

The risk of newborn infant mortality is commonly associated with hypothermia. Hypothermia is a health disorder and a leading cause of death in newborns, caused by an imbalance in the baby's body temperature. Hypothermia occurs due to a decrease in body temperature resulting from various conditions, especially high oxygen requirements and a decrease in room temperature. The purpose of this study is to monitor the health status of newborns. Monitoring the body temperature and oxygen saturation levels in newborns can help detect abnormalities in infants at an early stage. Oxygen saturation is considered a vital sign that is important in supplying oxygen to the body. This research is expected to assist patients using a baby cuve in providing care for newborns with hypothermia symptoms. The Baby Cuve utilizes the DS18B20 sensor for temperature measurement and the MAX3102 sensor for heart rate and oxygen saturation. The data is then processed using the ESP32 microcontroller, and the results are displayed on an LCD screen. The comparative tools used in this study are the standard thermometer and pulse oximeter. The results of this research indicate that the smallest measurement error value is found in the Spmeasurement of respondent 10, which is 0.1%. The largest measurement error value is found in the Spmeasurement of respondent 2, which is 5.6% based on the obtained data. However, the measurement results are still within the tolerance limit of ±10%.

S-shaped tellurite optical fiber surface plasmon resonance sensor for temperature and refractive index measurement

In this paper, an all-fiber S-shaped structure optical fiber surface plasmon resonance (SPR) sensor is proposed for temperature and refractive index measurement. The sensor is made of a single-mode tellurite optical fiber (TOF), and the middle part of the single-mode TOF is heated by a ceramic heating rod to form an S-shaped sensing region, and a 50 nm gold film is deposited in the S-shape sensing area to excite SPR. Based on the excellent properties of tellurite optical fiber, the prepared optical fiber sensor can be used for high sensitivity temperature and refractive index detection. The highest refractive index sensitivity is up to 1068.59 nm/RIU in the range of 1.333–1.380, and the temperature sensitivity is up to −0.713 nm/°C in the range of 30–150 °C. The proposed sensor is simple to fabricate, low-cost, and compact, and can be widely used in biochemical analysis, complex environmental temperature monitoring and other fields.

Integrating Interference and Resonance Effects in Microfiber Sensors for Simultaneous Pressure and Temperature Measurement

Integrating Interference and Resonance Effects in Microfiber Sensors for Simultaneous Pressure and Temperature Measurement

Femtosecond laser etching C-type fiber optic vernier sensor for seawater temperature and salinity measurements

In this work, we demonstrate a dual C-type fiber optic vernier sensor based on femtosecond laser etching for measuring seawater temperature and salinity. The C-type fibers are etched using femtosecond laser microfabrication technology on hollow-core fibers (HCF), including temperature and salinity cavities. The seawater can fully flow into the salinity cavity as a sensing medium, and the polydimethylsiloxane (PDMS) is filled into the temperature cavity as a sensitizing medium. Combined with the vernier effect, dual parameter high sensitivity simultaneous measurement is achieved. Through simulation and experimental testing, the sensor can achieve high sensitivity measurement of seawater salinity and temperature, with sensitivities of −2.69 nm/‰ and −4.54 nm/℃, respectively. In the stability tests of salinity and temperature, the maximum interference wavelength shifts are 0.52 nm and 0.64 nm, respectively. In the repeated measurement experiment, the maximum deviation of sensitivity for salinity cavity and temperature cavity measurements are 0.03 nm/‰ and 0.18 nm/℃, respectively, indicating that the structure has good measurement stability and repeatability. This sensor has the advantages of strong stability, good repeatability, and low cost, which can be used as a new type of sensor to achieve high-sensitivity detection of seawater parameters.

Research and Design of A Multifunctional Heart Rate Detection System

Addressing the limitations of conventional heart rate detectors, which solely monitor heart rate without providing alerts during critical incidents, a multifunctional heart rate detection system has been developed. This system incorporates a GD32 as the main controller and utilizes a pulse sensor for heart rate monitoring, an MLX90614 infrared temperature sensor for body temperature measurements, an MPU6050 acceleration sensor for motion posture detection, and a SIM868 module for GPS positioning and server communication. This comprehensive setup allows for real-time monitoring of the wearer's heart rate and body temperature, assessment of fall incidents based on motion posture data, and regular uploading of health data to a server. Additionally, the system is equipped with a one-touch emergency call feature. In the event of abnormal heart rate readings or a fall, it triggers an alarm, acquires GPS coordinates, and automatically dials an emergency contact number. After thorough testing and verification, the system has demonstrated full functionality with heart rate data accuracy within the expected error range, offering a reliable safety mechanism for patients while on the move.

Simultaneous bending and temperature measurement based on a superimposed fiber grating sensor

A compact and novel superimposed fiber grating (SI-FG) sensor for simultaneous measurement of temperature and bending based on UV-induced FBG cascaded with a multimode fiber (MMF) embedded ultra-long period fiber grating (MMF-EULPFG) has been proposed and experimentally validated. The MMF-EULPFG acts as a temperature and bending sensing unit and was fabricated by periodically splicing a non-UV-non-photosensitive MMF and a UV-photosensitive single-mode fiber (SMF) which is so called cleaving-splicing method. Due to the periodic refractive index modulation, the 6-period SMF-MMF structure based MMF-EULPFG with a total length of 2.7 mm forms transmission spectra with a −17 dB dip. The proposed SI-FG sensor exhibits high bending and temperature sensitivities of 17.096 nm/m−1 and −0.238 nm/℃, respectively. The UV-induced FBG is fabricated in the initial segment of UV-sensitive fibers within EULPFG by UV exposure method. The dip of FBG transmission spectra also shows response to bending and temperature. By utilizing a matrix obtained from the experimental results, simultaneous measurement of temperature and bending can be achieved. Due to its compact structure and high sensitivity, the proposed novel SI-FG sensor can be used as a competitive all-fiber sensor for structural health monitoring and 3D-shape sensing.Index Terms: Optical fiber sensor, long period fiber grating, superimposed fiber grating, simultaneous measure.

Tilted Bragg grating in a glycerol-infiltrated specialty optical fiber for temperature and strain measurements.

In this Letter, we propose an in-line tilted fiber Bragg grating sensor for temperature and strain measurements. The grating is inscribed in a specialty optical fiber using tightly focused femtosecond laser pulses and the line-by-line direct writing method. Beside the central core in which the grating is produced, a hollow channel filled with glycerol aqueous solution significantly improves the sensitivity of the fiber cladding modes due to its high thermo-optic coefficient. We show that the temperature sensitivity of the core mode is 9.8 pm/°C, while the one of the cladding modes is strongly altered and can reach -24.3 pm/°C, in the investigated range of 20-40°C. For the strain measurement, sensitivities of the core mode and the cladding modes are similar (∼0.60 pm/με) between 0 and 2400 με. The significative difference of temperature sensitivity between the two modes facilitates the discrimination of the dual parameters in simultaneous measurements.