Sensor For Measurement Of Temperature Research Articles

PV system frequency regulation employing a new power reserve control approach and a hybrid inertial response

The integration of photovoltaic (PV) systems into power grids has become a popular way to provide sustainable, low-cost energy. However, the lack of internal inertia in PV systems, as well as the continuous operation of PV plants at maximum power point, might pose challenges for grid stability and frequency control. The commonly employed method to participate in the frequency control is to operate the PV plant in a deloading mode at reduced power. As a result, a virtual inertial and primary frequency control can be provided. However, operation in a deloading mode may require complex algorithm and sensors for irradiation and temperature measurement. In addition, the virtual inertia reliability is dependent on power electronics, processors, and control. This paper presents two alternative techniques for dealing with frequency control. The first one combines simplicity and the absence of irradiance and temperature sensors by using a novel power reserve control (PRC) technique based on PV voltage variation. It has a two-mode cycle, with the first mode being used to calculate and reach the MPPT point and the second mode being used to provide the appropriate power reserve. The cycle continues in PRC mode until a triggering event is generated by an implanted device that captures the PV system’s voltage change. In this study, the PRC approach is applied to offer primary frequency control (PFC) and virtual inertia (VIC). The second technique addresses the lack of real rotational inertia in PV systems. In this paper, we suggest incorporating a synchronous generator into the PV plant without providing active power. Its main role is to offer an intrinsic real inertial response. In addition, a hybrid approach based on virtual and real inertial response is investigated and discussed. To model and simulate the entire system in an isolated and interconnected power grid, Matlab software is employed. Both proposed approaches are tested and validated in the presence of climate changes and large perturbations affecting the grid.

Implementasi Telegram untuk Budidaya Lumbricus Rubellus Berbasis IoT

Lumbricus Rubellus (earthworm) has various benefits: serving as livestock feed, medicine, cosmetics ingredients, and organic fertilizer from vermicompost. Earthworm cultivation is not difficult, but requires extra monitoring due to various challenges that affect their growth and development. One key factor to consider is the weather, as prolonged hot temperatures during droughts can disrupt the growth of earthworms. To address this challenge, a monitoring and control device was designed to regulate the temperature and humidity of the cultivation area automatically. Additionally, the device provides information about the age of the cultivated earthworms for predicting the harvesting period. These functions were realized by utilizing various sensors, such as the DHT11 sensor for room temperature measurement with 95.05% accuracy and the Soil Moisture sensor for soil humidity measurement with 96.3% accuracy. Furthermore, a fan and water pump were employed to automate temperature and humidity regulation. The main control unit for this system is the NodeMCU ESP8266. Telegram application was used as a platform to monitor and control this IoT-based device remotely. With this device, the process of earthworm cultivation is expected to be more accessible.

A novel surface plasmon resonance sensor sensitivity enhancement method for temperature measurement by depositing tungsten disulfide nanosheets on the silver film

Surface plasmon resonance (SPR) sensors are extensively used with refractive index and temperature sensing. A novel SPR sensor for temperature measurement is proposed in this paper. A novel two-dimensional material Tungsten disulfide is used to improve the sensitivity of this temperature sensor. Polydimethylsiloxane covers the sensing area to better sense changes in external temperature. The experimental results show that the SPR sensor can measure the temperature range of 30 °C − 100 °C with a temperature sensitivity of 2.03 nm/°C. This sensor has the merits of a simple structure, low manufacturing process cost, a broad range of detection, and high sensitivity compared to other temperature sensors. Therefore, the sensor has great potential for future applications in environmental monitoring, biomedicine, the food industry, and other production activities.

Dual-Parameter Sensor for Temperature and Strain Measurement Based on Antiresonance Effect and Few-Mode Fiber

A simple and novel hybrid interferometer based on the antiresonance (AR) effect and Mach–Zehnder interference (MZI), which enables simultaneous measurement of temperature and strain, is proposed and investigated. The sensor is made by cascading a 30 cm section of a few-mode fiber (FMF) and a 3.376 mm hollow-core fiber (HCF) through a single-mode fiber (SMF). The FMF and SMF are fused without misalignment to excite two stable modes, thereby forming a Mach–Zehnder interferometer. Concurrently, the introduction of HCF can effectively excite the AR effect, which is manifested in the transmission spectrum as two different dips at the same time caused by the difference in the two physical mechanisms, showing diverse responses to both external temperature and strain. This difference can be used to construct a cross-coefficient matrix to implement the simultaneous measurement of temperature and strain. The experimental results demonstrate that the AR effect and MZI correspond to strain sensitivities of –0.87 and –2.29 pm/µε, respectively, and temperature sensitivities of 15.68 and –13.93 pm/°C, respectively. Furthermore, the sensor is also tested for repeatability, and the results show that it has good repeatability and great potential in sensing applications.

Design of mask recognition and temperature monitoring system

This design is based on the STM32F103C8T6 mask recognition and temperature monitoring system, mainly including the mask recognition module based on the K210 chip, non-contact infrared temperature sensor module based on the ATmega328P chip, liquid crystal display module, infrared tube sensor module and buzzer module. When the infrared tube sensor senses the measured target, the system starts to supply power to ATmega328P. The infrared temperature measurement sensor module MLX90164 is used to measure the temperature of the target. At the same time, the temperature data is displayed on the LCD1602 display screen. If it exceeds the predetermined value, an alarm will be issued. When the temperature is normal, the system starts to supply power to K210, start the camera, lock the face position, identify whether the target is wearing a mask, and display the measured results through the 2.4-inch TFT screen. If the mask is worn correctly, the face frame will turn green. Through the software program, the three chips are mobilized for coordinated operation, the target body temperature is measured by using the temperature compensation algorithm, and the mask recognition is carried out by using the YoloV2 algorithm. The hardware design and software program design are improved, and finally, the material object is made. After repeated debugging of the real object, the expected effect is finally achieved. After gradual product improvement, it will be widely used in the daily monitoring of mask wearing identification and body temperature detection in the normalization of epidemic prevention and control in public places in the future.

Porous silicon-polyvinylidene fluoride-carbon dots based portable temperature sensor

Optical sensors are an attractive alternative to semiconductor-based sensors for temperature measurement in harsh environments. Based on Porous Silicon (PSi) Fabry-Perot interferometer, this work presents a novel way of sensing temperature with PSi hybrids using a polymeric nanocomposite of polyvinylidene fluoride (PVDF) and carbon dots (CDs). The operation is based on the temperature-induced changes in the refractive index of PVDF, which in turn changes the effective refractive index of the PSi hybrid. The dual temperature sensing was based on the simultaneous monitoring of the peak wavelength redshift of the Fabry-Perot interference fringes, and the measurement of the intensity of the reflectance spectrum at a specific wavelength. Both measurements showed excellent linear responses, with coefficients of determination greater than 0.99, revealing the highest sensitivity of 0.2 nm/°C for the sample with the highest content of CDs. Apart from the enhanced temperature dependence of the dielectric constant of PVDF, which improved the sensitivity of the proposed PSi/PVDF-CDs based sensors, the hybrid structure facilitates the formation of β phase up to 91.8%. The proposed silicon-based temperature sensor being very large-scale integration (VLSI) compatible, open the way towards the possible formation of free-standing PSi/PVDF-CDs films with a possible application as biocompatible micro temperature sensors.

Improved sensitivity of temperature sensor based on three-photons pumped upconversion in highly transparent Er3+ doped lead lanthanum zirconate titanate ceramics

Efficient two-photons and three-photons pumped upconversion emission were investigated in highly transparent Er3+ ions doped lead lanthanum zirconate titanate ceramics excited by using near infrared lasers centered at 980 nm, 1064 nm, and 1550 nm. Temperature dependent spectral changes of the multi-photons upconversion emission were explored, and highly sensitive temperature sensors were obtained based on the energy difference between 2H11/2 and 4S3/2. Using this temperature sensor, the temperature changes of the Er3+ ions doped lead lanthanum zirconate titanate ceramics was tested by irradiating the sample with a high-energy femtosecond laser at 1550 nm. This work is useful for developing a highly sensitive non-contact temperature measurement sensors, which provides the necessary theoretical basis for its practical application.

Smart wearable flexible temperature sensor with compensation against bending and stretching effects

Flexible and stretchable temperature sensors have recently gained much attention due to their lightweight, thin profile, and ability to adapt to curved or irregular surfaces. Resistive temperature detectors (RTD) are one of the most commonly used sensors for temperature measurement. However, the major challenge with developing RTDs on flexible substrate is that the resistance not only changes with temperature, it also varies with mechanical deformation of the substrate, which can lead to significant errors in temperature measurement. In this paper we propose a novel flexible temperature sensor that can compensate for the deformation-induced resistance variation and measure temperature with minimum errors. The sensor is composed of two RTDs fabricated back-to-back on a polydimethylsiloxane (PDMS) substrate via stencil printing. The dual RTD configuration provides compensation against mechanical deformation caused by bending and stretching. When the sensor is bent on a curved surface, the resistances of the two RTDs change differentially due to tension on one RTD and compression on the other. As a result, the sum of resistance of both RTDs, RSum, remains a constant. Similarly, the subtraction of resistance of the two RTDs, RSub, can be used to compensate for the linear resistance change in sensor stretching. With the compensation methods in place, the sensor can be used for temperature measurement with enhanced accuracy. In addition, the sensor is connected to a Bluetooth-integrated microcontroller which is programmed to determine whether the sensor is undergoing bending or stretching. The compensation methodology can provide reliable measurement for a maximum radius of 40 mm when the sensor is bent or a maximum strain of 3% when it is stretched. The compensation method enhances the competence of flexible temperature sensors and increases their potential for applications in wearable electronics.

An optimum design of high sensitivity PMMA-coated FBG sensor for temperature measurement

Fiber Bragg grating (FBG) with silica material has limitations in measuring mechanical quantities such as strain and temperature, this happens because silica fibers are easy to break at higher transverse or axial strains. This deficiency can be overcome in several ways, one of which is by coating the silica FBG with a coating material made of metal or polymer. In this research, the FBG sensor has been designed by poly methyl methacrylate (PMMA)-coated FBG and silica. The finite element method (FEM) is used to analyze the electric field distribution on the surface of PMMA coated FBG with a coating thickness of 20 µm. Furthermore, the sensitivity of each coated FBG as a temperature sensor was measured in the range of 25 ℃ to 85 ℃ using coupled mode theory (CMT). From the design and analysis of coated FBG, it was found that FBG coated with PMMA material had the highest sensitivity of 395.73pm/℃. However, the FBG sensor coated with silica material has a sensitivity of 13.73 pm/℃. the shift obtained is also linear along with the temperature of 25 ℃ to 85 ℃.

RANCANG BANGUN ALAT KEHADIRAN OTOMATIS MENGGUNAKAN QRCODE DILENGKAPI DENGAN PENGUKUR SUHU BADAN DAN CUCI TANGAN

At the beginning of 2020 the world was shocked by the outbreak of the corona virus which infected almost all countries in the world. WHO since January 2020 has declared the world to be in a global emergency related to the Covid-19 virus. As a preventive measure, every public facility and shop must have hand washing equipment, check body temperature before entering the room so that people who have a high temperature must go to the doctor, this also applies to schools to prevent new clusters in the educational environment. In this journal, the presence of a QRCODE-based automatic tool using the MLX90614 temperature sensor to measure body temperature is connected to the Arduino UNO microcontroller and displayed on the LCD in the form of temperature sensor measurement data and OLED displays QRCODE data scanned using the presence application. The Sensor Module MLX90614 has an IR sensitive thermopile detector chip and a signal conditioning ASIC integrated in the sensor packing model TO-39. The signal conditioning in the form of a low noise amplifier, 17-bit ADC and a powerful DSP unit achieves the accuracy and high resolution of the thermometer. The attendance application is made forAndroid smartphones, students can scan the QRCODE to make attendance through an application on an Android smartphone, so using the QRCODE can speed up and simplify receiving information obtained on the smartphone application. Testing of the prototype tool was carried out at Pupuan One Roof Public Middle School 6, a trial was carried out with several students, the lowest measurement difference was 0.2 °C and the highest was 0.5 °C with a measurement distance of 5 cm from the sensor surface. The prototype can be used for attendance from checking temperature, washing hands and making attendance from a smartphone then the data is submitted and stored in the Firebase database.

Real-time monitoring and prediction method of commercial building fire temperature field based on distributed optical fiber sensor temperature measurement system

In order to accomplish the task of real-time monitoring and prediction of fire temperature in commercial buildings, this study proposes a sensor arrangement method based on sensor and fire field characteristics to better reflect the fire temperature changes of building space, and conducts high temperature sensor measurement experiments based on this method. Then the study carries out fire dynamics simulations to establish a temperature change dataset containing fire and sensor temperature changes. The study establishes several prediction models using different algorithms based on the dataset, and the models built by artificial neutral network (ANN) and long short-term memory (LSTM) respectively have the best performance. The results show that the percentage error between the output temperature of the ANN mapping model and the actual temperature of the fire key plane is 1.94%. The percentage error between the output temperature of the LSTM temperature prediction model and the actual temperature is 1.03%, which satisfies the demand for early warning of the fire temperature hazard. This study also validates the generalization of the two models for fire temperature prediction in different spatial areas, and the method can provide a good solution for real-time monitoring and early warning of fire temperature in commercial buildings.

A compact LWIR borescope sensor for 2D engine component surface temperature measurement

A compact long-wavelength infrared (LWIR) borescope imaging sensor operating in the wavelength range of 8–14 μm is designed and developed for non-contact two-dimensional (2D) surface temperature measurements in gas-turbine engines. The LWIR detection minimizes optical interferences from hot combustion gases and soot (emission within UV–mid IR region). Using simulations, the system is optimized for improving the signal collection efficiency and minimize image aberrations. The LWIR borescope probe is shielded by the custom-build compact water-cooled probe housing (outer diamter (OD) 19 mm, inner diameter (ID) 10 mm), which can sustain flame temperature up to 2400 K at a pressure of 50 bar. It facilitates long-term optical diagnostics inside the actual high-pressure combustion facilities where extreme thermal acoustic perturbation and intense heat fluxes are encountered. The design, construction, and characterization of the LWIR borescope sensor are discussed in detail. We present the 2D surface temperature measurements of a V-gutter bluff-body with simple nitrogen gas cooling in a laboratory testbed. The results indicate the sensor’s ability to accurately measure surface temperature with low background noise and to track transient cooling effect. The water-cooled probe housing was tested to verify the effectiveness of fast heat dissipation in high-temperature combustion environment to avoid unwanted thermal signals from the LWIR probe window. The developed LWIR sensor suite has promising applications in surface temperature measurements of engine components. The findings of this study may aid propulsion system engineers and researchers in designing thermal management systems and optimizing operation.

Highly sensitive sensor for simultaneous underwater measurement of salinity and temperature based on highly birefringent asymmetric photonic crystal fiber

This paper describes a novel compact fiber sensor with high sensitivity for the simultaneous measurement of underwater salinity and temperature by simulation. The structure is based on a highly birefringent, asymmetric, full-circular hole photonic crystal fiber (HB-A-FCH PCF), which achieves the birefringence value of 2.83 × 10-3 at the wavelength of 2.2 µm. In addition, with ethanol-filled specific air holes, the temperature sensitivity of HB-A-FCH PCF is remarkably improved. Therefore, considering the high birefringence property, we simulate a Michelson interferometer-based sensor setup with air holes as fluid microchannels and simultaneously measure salinity and temperature through the spectral responses of the x- and y-polarization state. Theoretical analysis shows the sensor can achieve the salinity and temperature sensitivity up to 5.1472 nm/% and −0.8987 nm/°C in x-polarized fundamental mode, respectively, whereas the salinity and temperature sensitivity up to 4.5386 nm/% and −0.8000 nm/°C in y-polarized fundamental mode, respectively.

Dual-FBG and F-P Cavity Compound Optical Fiber Sensor for Simultaneous Measurement of Bending, Temperature and Strain

A dual-FBG and F-P cavity compound optical fiber sensor based on a multi-core fiber (MCF) is proposed. A hollow core fiber (HCF) was fused between a single-mode fiber (SMF) and a MCF to form the F-P cavity. Two FBGs with different reflective wavelength were prepared on a side core (SC) and the central core (CC) of MCF respectively. An asymmetric 45° reflector was fabricated at the end of the MCF to make the optical path of the dual-FBG and the F-P cavity in series. The combination of the F-P cavity and the FBG on the CC can measure temperature and axial strain, simultaneously, while both of them are insensitive to bending. The FBG on the SC is sensitive to bending and can be used for curvature measurement, and the temperature and axial strain compensation can be achieved by the combination of the F-P cavity and FBG on the CC. Therefore, the curvature, axial strain and temperature can be measured simultaneously by the compound sensor on a single optical fiber.

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.

Simultaneous measurement of trace dimethyl methyl phosphate and temperature using all fiber Michaelson interferometer cascaded FBG.

All fiber Michaelson interferometer cascaded fiber Bragg grating (FBG) sensor for simultaneous measurement of trace dimethyl methyl phosphate and temperature is proposed. One end of the four-core fiber (FCF) is spliced with a multimode fiber (MMF), the other end is flattened and evaporated with silver film to enhance reflection, and the Michelson interference structure is formed. The grating is engraved in the single-mode fiber (SMF) core and spliced with MMF, then the Michelson interference cascaded FBG, FBG-MMF-FCF sensor is obtained. The sensing film, MnCo2O4 is coated on the surface of FCF, and the structure, elemental composition and morphology of MnCo2O4 were analyzed by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy. The sensitivity and the detection limit of DMMP are 86.44 dB/ppm and 0.1767 ppb, respectively. The response/recovery time is about 14/10 s. the temperature sensitivity can be compensated and calculated as 0.069 nm/°C. The sensor has good selectivity and stability, and has a good application prospect in high sensitivity detection of trace DMMP vapor.

Abstract WP113: Feasibility Of Non-invasive Brain Temperature Measurement In Acute Ischemic Stroke: A Comparison Study Of MR Thermometry Vs. Zero-Heat-Flux Sensors

Introduction: Brain-selective hypothermia is a promising neuroprotectant in acute ischemic stroke. However, a non-invasive bedside method to monitor brain temperature during cooling is lacking. We tested the feasibility and accuracy of measuring brain temperature non-invasively using sensors designed to monitor core body temperature. Methods: In this prospective single-center study, 20 patients with large or medium vessel occlusion strokes were enrolled. Patients underwent a 3T MR spectroscopy imaging (MRSI, the reference standard) and zero heat flux (ZHF) core temperature sensor measurements (3M TM Bair Hugger TM ) within 12-72 hours from admission. Two ZHF sensors were placed on each side of the forehead on the side of stroke and contralateral side and the temperatures were checked before and after MRSI. A 2x2x2 cm voxel was centered on the infarct and matching contralateral location using diffusion weighted imaging. Brain temperature on MRSI was calculated using the relative chemical shifts of water and N-acetyl aspartate. Temperature measurements of the ZHF sensors were compared to MRSI measurements. Results: The brain temperature of stroke and contralateral sides were similar using MRSI or using ZHF sensors when each modality was compared to itself by hemisphere (all p>0.05). However, there was a significant difference for the ipsilateral side: median (SD) temperatures using MRSI was 36.0°C (1.8) vs 36.8°C (0.5) for sensor measurement. Bland-Altman plots showed that 95% of the observations fell within upper and lower limits of agreement of -2.1 to +3.7°C while 61% of observations fell within an agreement limit of +/- 1°C. There was an indication of an overall higher temperature measurements using the ZHF sensors compared to MRSI (Figure 1). Conclusions: More studies are needed to validate the use of ZHF thermometry in ischemic stroke including studies implementing hypothermia. Figure 1. Boxplot of stroke side MRSI compared to zero-heat-flux sensors.

Improvement of Student Attendance System for Recording Student Surface Body Temperature Based on Internet of Things

Student attendance is a system used for tracking student activity in school. Many methods are used to develop student attendance systems, such as Quick Response (QR) Code systems, Radio Frequency Identification (RFID) systems, fingerprint systems, and so on. The COVID-19 pandemic has driven technological development, especially in the student attendance system. Measuring human surface body temperature has become a protocol that must be done before entering school. Student attendance systems need to expand the function not only for attendance but also for monitoring student surface body temperature. This research aims to improve student attendance systems by adding surface body temperature measurements and recording during student presence. Recording data can be done by using the internet of things. Student presence data will be sent to school databases throughout the internet. This system uses RFID technology for student presence and a non-contact thermal sensor for temperature measurement. According to data research, non-contact thermal sensors provide a temperature reading with an average error of 1.69%, a minimum error value of 0.96%, and a maximum error value of 2.57% with a range error value of 0.35°C – 0.95°C. RFID test shows that the optimum distance for the system to read an RFID card is 0 – 2cm. The System also successfully sent presence data to the student school database through the internet. This study concludes that developed systems can track student attendance by recording the student’s surface body temperature while in presence. Further work will be focused on managing data networks if this system is used with many users in the school.

Probe type TFBG-excited SPR fiber sensor for simultaneous measurement of multiple ocean parameters assisted by CFBG.

The tilted fiber Bragg grating(TFBG), chirped fiber Bragg grating(CFBG), Vernier effect and metal surface plasmon resonance(SPR) effect are effectively combined to form a probe type fiber sensor for simultaneous measurement of seawater salinity, temperature and depth(STD). The SPR effect excited by the TFBG is achieved by covering a gold layer around the TFBG, which is used to measure the refractive index (RI) of seawater. The core mode of TFBG is used to detect the change of seawater temperature and the measurement of TFBG reflection spectrum is realized by inscribing a CFBG after the TFBG, which makes the sensor have a probe type design and more beneficial to practical applications. The fusion of quartz micro-spheres on the end face of the sensing fiber and the parallel connection of an Fabry Perot(F-P) interference cavity enables the use of Vernier effect to detect the depth of the ocean. Femtosecond laser line-by-line method is used to the inscribing of TFBG, which allows the grating parameters to be changed flexibly depending on the desired spectrum. The experimental results show that the temperature sensitivity is 10.82pm/°C, the salinity sensitivity is 0.122nm/g/Kg, the depth sensitivity is 116.85 pm/m and the depth can be tested to 1000 m or even deeper.

Temperature Measurements by Wavelength Modulation Diode Laser Absorption Spectroscopy with Logarithmic Conversion and 1f Signal Detection

A new version of a sensor for temperature measurements in the case of strong laser intensity fluctuation was developed. It was based on tunable diode laser absorption spectroscopy (TDLAS) with wavelength modulation, logarithmic conversion of the absorption signal, and detection of the first harmonic of the modulation frequency. The efficiency of the technique was demonstrated under experimental conditions with excess multiplicative noise. Temperature was evaluated from the ratio of integrated absorbance of two lines of the water molecule with different lower energy levels. Two algorithms of data processing were tested, simultaneous fitting of two spectral ranges with selected absorption lines and independent fitting of two absorption lines profiles. The correctness of the gas temperature evaluation was verified by simultaneous measurements with a commercial thermocouple. An error in temperature evaluation of less than 40 at 1000 K was achieved even when processing a single scan of the diode lasers.