Calibration Of Thermometers Research Articles

Analysis of Temperature Stability and Accuracy on the Design of Thermometer Calibrator Based on Fuzzy Logic And On/Off Control

A thermometer is a medical device used to measure body temperature. To maintain the accuracy of the thermometer measurement results, periodic calibration is required. Calibration is an activity to determine the conventional correctness of the indicator values of measuring instruments and measuring materials by comparing them with measurement standards that can be traced to national and international standards for units of measure and/or international and certified reference materials. Based on the results of the identification of chronological problems that have been observed, a body thermometer that measures body temperature is needed so and a calibrator is needed to maintain the accuracy of the thermometer. The purpose of this study was to analyze the Temperature Stability and Accuracy of the Body Thermometer Calibrator Based on on-Off Control and Fuzzy Logic Control. The contribution of this research to this tool will use the development of a fuzzy logic control method to produce temperature stability in the Body Thermometer Calibrator (Digital). The method used in this study used fuzzy control and on-off control. The results of this study from the suitability test obtained a maximum error of 0.2% in the fuzzy control and 0.6% in the On-Off control. The average rise time difference for the two controls was 13.53 Seconds. The average settling time difference is 130.46 seconds. The results of this study can be concluded that the Fuzzy System is better than the On / Off system so the Fuzzy system is more suitable for thermometer calibration media.

Design of Wet Media Digital Thermometer Calibrator Based on ATmega328p

Temperature calibration is an activity that formed the relationship between values indicated by a measuring instrument or measuring system with the value - the value relating to the temperature scale that measured under certain conditions. A clinical thermometer is a device that doctors use to measure the temperature inside a patient's body. In the field of calibration, the suitability of medical device readings with the permissible standard values ​​(tolerance values) is very necessary so that the readings are kept accurate. The purpose of this research is to make a digital wet media thermometer calibrator based on the ATmega32p to monitor the performance of the thermometer with a temperature setting of 35 °C – 40 °C in order to maintain its accuracy. The design of this calibrator consists of a wet heater circuit using a DS18B20 temperature sensor which is processed by a minimum ATmega328p system, then will be displayed on a 2x16 LCD. This tool is made to make it easier to calibrate the thermometer so that its accuracy is maintained. Thermometer calibration is done by comparing the module with a calibrated standard measuring instrument. The measurement of the instrument against the setting temperature has the smallest error of 0% and the largest of 0.25%. Meanwhile, the measurement of the instrument against a standard thermometer (which has been calibrated) has the smallest error value of 0% and the largest of -1.17%.

Constraining the ^{30}P(p, γ)^{31}S Reaction Rate in ONe Novae via the Weak, Low-Energy, β-Delayed Proton Decay of ^{31}Cl.

The ^{30}P(p,γ)^{31}S reaction plays an important role in understanding the nucleosynthesis of A≥30 nuclides in oxygen-neon novae. The Gaseous Detector with Germanium Tagging was used to measure ^{31}Cl β-delayed proton decay through the key J^{π}=3/2^{+}, 260-keV resonance. The intensity I_{βp}^{260}=8.3_{-0.9}^{+1.2}×10^{-6} represents the weakest β-delayed, charged-particle emission ever measured below 400keV, resulting in a proton branching ratio of Γ_{p}/Γ=2.5_{-0.3}^{+0.4}×10^{-4}. By combining this measurement with shell-model calculations for Γ_{γ} and past work on other resonances, the total ^{30}P(p,γ)^{31}S rate has been determined with reduced uncertainty. The new rate has been used in hydrodynamic simulations to model the composition of nova ejecta, leading to a concrete prediction of ^{30}Si:^{28}Si excesses in presolar nova grains and the calibration of nuclear thermometers.

Microcontroller based study of diode thermometers for online demonstration of undergraduate laboratory classes in COVID-19 lockdown

At constant current (I) the forward bias potential (V) of a pn junction diode may be considered to vary linearly with temperature (t) within a temperature range. Based on this property we have constructed diode thermometer using germanium (Ge) and silicon (Si) diodes. The experimental data at constant forward current have been fitted to a straight line for calibration of the diode thermometers using the least square method. Furthermore, the fitting parameters of the straight line have also been used to determine the band gap energy of germanium and silicon and experimental values of band gap for both the semiconductor materials are found to agree well with accepted values.

Enhancing the Thermal Gradient of Thermometer Calibration Systems with an Assembly of Water Heat Pipes Sealed in a Cu Tube

Enhancing the Thermal Gradient of Thermometer Calibration Systems with an Assembly of Water Heat Pipes Sealed in a Cu Tube

Enhancing the Thermal Gradient of Thermometer Calibration Systems with an Assembly of Water Heat Pipes Sealed in a Cu Tube

Enhancing the Thermal Gradient of Thermometer Calibration Systems with an Assembly of Water Heat Pipes Sealed in a Cu Tube

Calibration of the dual-mode auto-calibrating resistance thermometer with few-parts-per-million uncertainty

The dual-mode auto-calibrating resistance thermometer (DART) has recently been proposed for highly accurate temperature measurement based on noise thermometry. In this paper, it is demonstrated that calibration and operation of the DART at part-per-million (ppm) level should be possible with the hardware developed. For this purpose, we have extensively tested a representative signal path comprising the basic DART components. This includes a low-noise amplifier connected to a 24-bit ADC and a metrology-grade voltage reference. A Josephson arbitrary waveform synthesizer (JAWS) generates a pseudo-noise consisting of low-distortion multitones superimposed on a low-frequency square-wave reference voltage. Using this signal, a fast and efficient calibration scheme for the signal path gain is demonstrated. The reference voltage stabilizes the gain at ppm level. We observed gain fluctuations within over a period of 19 d, a temperature coefficient of , and insignificant nonlinearity within an uncertainty band of for rms input levels between 5 µV and 80 µV. The behavior of the signal path with a 300 Ω resistor as a noise source was also investigated. From the observed stability of the voltage reference and flatness of the noise gain between 10 kHz and 225 kHz, we estimate that the presented hardware components are suitable for temperature measurements with systematic uncertainties well below .

Eastern Mediterranean climate change deduced from the Soreq Cave fluid inclusion stable isotopes and carbonate clumped isotopes record of the last 160 ka

A fundamental issue in the interpretation of speleothem calcite δ18Occ records is the correct partitioning of the effects of temperature and water δ18O variations. This study explores the paleo-environmental evolution of the Eastern Mediterranean Sea (EMS) region using Soreq Cave speleothems in the last 160 ka, a period covering glacial MIS6 to the present, through the independent determinations of temperatures via carbonate clumped isotopes (Δ47) and fluid inclusion δ18Ow, δDw and d-excess values of cave water entrapped in the speleothems. The observed general agreement between the trends in water δ18Ow composition directly measured from fluid inclusions and calculated from Δ47 temperatures and δ18Occ support the robustness of the data. Δ47 temperatures, derived using a revised thermometer calibration that includes recent modifications in 17O correction, vary from high values of 20–22 °C during interglacial periods to low values of 11–12 °C in cold glacial and stadial periods. Temperatures of 19–22 °C are observed during the time of deposition in the EMS of sapropel S5 in the last interglacial MIS5e period and sapropel S1 in the early Holocene, immediately following Terminations II and I, respectively. The Soreq Cave Δ47 temperatures generally agree with previously estimated EM sea surface temperatures, in support of the absence of a significant land-sea temperature gradient. Cave water δ18Ow values show large variations (from ∼-3 to −7.5‰), with high glacial and low interglacial values. These variations are largely explained by changes in Mediterranean Sea water composition due to glacial ice melting and freshwater input during sapropel periods, combined with the effect of rainfall amounts during interglacial periods. An analysis of relative timing shows that temperature rise precedes hydrological changes in the initial stages of Termination events. Fluid inclusion d-excess values show clear variations between values similar to the Global Meteoric Water Line during cold periods and values similar to the local Eastern Mediterranean Meteoric Water Line (EMMWL) in warm periods.

Influence of Atmosphere on Calibration of Radiation Thermometers.

Current process of calibrating radiation thermometers, including thermal imagers, relies on measurement comparison with the temperature of a black body at a set distance. Over time, errors have been detected in calibrations of some radiation thermometers, which were correlated with moisture levels. In this study, effects of atmospheric air on thermal transmission were evaluated by the means of simulations using best available resources of the corresponding datasets. Sources of spectral transmissivity of air were listed, and transmissivity data was obtained from the HITRAN molecular absorption database. Transmissivity data of molecular species was compiled for usual atmospheric composition, including naturally occurring isotopologs. Final influence of spectral transmissivity was evaluated for spectral sensitivities of radiation thermometers in use, and total transmissivity and expected errors were presented for variable humidity and measured temperature. Results reveal that spectral range of measurements greatly influences susceptibility of instruments to atmospheric interference. In particular, great influence on measurements is evident for the high-temperature radiation pyrometer in the spectral range of 2–2.7 µm, which is in use in our laboratory as a traceable reference for high-temperature calibrations. Regarding the calibration process, a requirement arose for matching the humidity parameters during the temperature reference transfer to the lower tiers in the chain of traceability. Narrowing of the permitted range of humidity during the calibration, monitoring, and listing of atmospheric parameters in calibration certificates is necessary, for at least this thermometer and possibly for other thermometers as well.

Accurate Clinical Tympanic Thermometer Measurement System at NMISA

Infrared ear thermometers allow users to measure body temperature quickly and non-invasively by inserting a probe into the patient’s ear canal. The effectiveness of tympanic ear thermometers is dependent on how accurate their measurement is. This prompts the demand for accurate and reliable calibration of ear thermometers. Developing capability and providing traceability to the health care facilities in South Africa have become crucial, as there is no calibration laboratory that provides such a service. A standard ear-thermometer black-body source system that is traceable to ITS-90 temperature has been constructed and assembled at the NMISA temperature laboratory. The ITS-90-traceable measurement system developed has a measuring capability of 40 mK (k=2) to 70 mK (k=2) in the temperature range of 35.5 °C to 41.5 °C. At the human body temperature of 37 °C an uncertainty of 45 mK (k=2) is achieved.

Design, construction and traceable calibration of a phosphor-based fibre-optic thermometer from 0 °C to 650 °C

Measurement traceability, in which there is a documented chain of calibration links from a measurement back to a primary realisation of a unit, is vital for achieving the smallest uncertainty in metrology. A sensor that can provide a traceable link in harsh environments may be advantageous even if its uncertainty is larger than that of typical calibrated devices. A phosphor-based thermometer that has optical rather than electrical connections has been built and then calibrated in terms of the International Temperature Scale of 1990. Its standard uncertainty ranges from 0.5 °C at 0 °C to 2 °C at 650 °C. While this uncertainty cannot match what is possible with thermocouples or resistance thermometers, the optical basis of the sensor means it can be used in situations where electrical connections are precluded.

Miniature iron-carbon eutectic point crucible for the calibration of thermometers

The article presents the design, construction and evaluation of a miniature graphite iron-carbon eutectic point crucible for the calibration of thermometers. These are either contact such as thermocouples or non-contact such as infrared thermometers. The double wall of the crucible protects its structure in case of cracks in graphite that can appear due to thermal expansion or eutectic adhesion. Such design proved robust – even after almost 100 melting realizations, the crucible does not show significant signs of damage. Performance of the crucible was confirmed with several realized plateaus at three different furnace setpoints. Results of these measurements agree with previously published findings. The measured melting point temperature was 1153.81 °C and the achieved expanded calibration uncertainty of a type R thermocouple was 0.2 °C.

A Unified Clumped Isotope Thermometer Calibration (0.5–1,100°C) Using Carbonate‐Based Standardization

AbstractThe potential for carbonate clumped isotope thermometry to independently constrain both the formation temperature of carbonate minerals and fluid oxygen isotope composition allows insight into long‐standing questions in the Earth sciences, but remaining discrepancies between calibration schemes hamper interpretation of temperature measurements. To address discrepancies between calibrations, we designed and analyzed a sample suite (41 total samples) with broad applicability across the geosciences, with an exceptionally wide range of formation temperatures, precipitation methods, and mineralogies. We see no statistically significant offset between sample types, although the comparison of calcite and dolomite remains inconclusive. When data are reduced identically, the regression defined by this study is nearly identical to that defined by four previous calibration studies that used carbonate‐based standardization; we combine these data to present a composite carbonate‐standardized regression equation. Agreement across a wide range of temperature and sample types demonstrates a unified, broadly applicable clumped isotope thermometer calibration.

Nongalvanic Calibration and Operation of a Quantum Dot Thermometer

A cryogenic quantum dot thermometer is calibrated and operated using only a single non-galvanic gate connection. The thermometer is probed with radio-frequency reflectometry and calibrated by fitting a physical model to the phase of the reflected radio-frequency signal taken at temperatures across a small range. Thermometry of the source and drain reservoirs of the dot is then performed by fitting the calibrated physical model to new phase data. The thermometer can operate at the transition between thermally broadened and lifetime broadened regimes, and outside the temperatures used in calibration. Electron thermometry was performed at temperatures between $3.0\,\mathrm{K}$ and $1.0\,\mathrm{K}$, in both a $1\,\mathrm{K}$ cryostat and a dilution refrigerator. The experimental setup allows fast electron temperature readout with a sensitivity of $4.0\pm0.3 \, \mathrm{mK}/\sqrt{\mathrm{Hz}}$, at Kelvin temperatures. The non-galvanic calibration process gives a readout of physical parameters, such as the quantum dot lever arm. The demodulator used for reflectometry readout is readily available and very affordable.

Thermal Finite Element Simulation of Dry Block Calibrator Based on Multi-fixed-Point Cells

On-site thermometer calibration by the temperature scale transfer technique based on fixed points can effectively improve the calibration level of thermometers in large-diameter hot water pipes. Calibrations of contact thermometers in large-diameter hot water pipes are often carried out using dry block calibrators. Axial temperature gradients and the drift of reference thermometers are the main sources of error for the use of the traditional dry block calibrators. To overcome these disadvantages, a new dry block calibrator with small multi-fixed-point cells was designed in this work to improve the homogeneity of the inner temperature field and calibrate the reference thermometers in situ. The calibrator was based on small multi-fixed points including the melting point of Hg (234.28 K), the melting point of Ga (302.91 K), the melting point of H2O (273.15 K) and was developed for use in the temperature range from − 50 °C up to 100 °C. The calibrator was designed using thermal Finite Element simulations carried out with COMSOL Multiphysics and has an ectopic multi-fixed-point structure. The melting process of the multi-fixed points was simulated using the effective heat capacity method, and the fraction of the liquid phase for the fixed-point material was obtained at different phase-transition radius values and temperature plateaus of multiple fixed-points cells were obtained at different dT values. The simulation explored the influence of different heating temperatures on the temperature plateaus of multiple fixed-points cells, and the functional relationship between the heating temperature and the temperature plateaus of multiple fixed-points cells was obtained, calculating the error between temperature plateaus and thermometer at different heating power, providing a technical basis for the subsequent prototype experiments and the validation of the prototype design through experimental measurements in future work.

Metal-carbon eutectic high temperature fixed points for in-situ calibration of radiation thermometers

The diffusivimeter of LNE has been modified by improving the inductive furnace used to heat the tested specimens in order to extend the operating temperature range up to 3000 �C. The temperature of specimen is one of the tricky parameters to be measured to ensure the relevance of the thermal diffusivity measurement and the associated uncertainty. At high temperature, radiation thermometers are used to determine the temperature of the specimens at which the thermal diffusivity measurements are performed. In addition to the periodic calibration of the radiation thermometers performed outside the experimental facility with black body sources, LNE proposes an in-situ verification method based on miniature high temperature fixed-point cells filled with metal-carbon eutectic alloys in order to detect and correct potential drift of the radiation thermometers between two out-of-process calibration operations. The proposed method enables high repeatable and reproducible temperature measurements on eutectic fixed-points (Pd-C, Pt-C and Ir-C) distributed in the range from 1500 �C to 2300 �C.

High-bandwidth, variable-resistance differential noise thermometry.

We have developed Johnson noise thermometry applicable to mesoscopic devices with variable source impedance with high bandwidth for fast data acquisition. By implementing differential noise measurement and two-stage impedance matching, we demonstrate noise measurement in the frequency range of 120 MHz-250MHz with a wide sample resistance range of 30 Ω-100kΩ tuned by gate voltages and temperature. We employed high-frequency, single-ended low noise amplifiers maintained at a constant cryogenic temperature in order to maintain the desired low noise temperature. We have achieved thermometer calibration with temperature precision up to 650 μK measuring a 200 mK temperature modulation on a 10K background with 30s of averaging. Using this differential noise thermometry technique, we measured thermal conductivity on a bilayer graphene sample spanning the metallic and semiconducting regimes in a wide resistance range, and we compared it to the electrical conductivity.

Composition-Thermometric Properties Correlations in Homodinuclear Eu3+ Luminescent Complexes.

A family of homodinuclear Ln3+ (Ln3+ = Gd3+, Eu3+) luminescent complexes with the general formula [Ln2(β-diketonato)6(N-oxide)y] has been developed to study the effect of the β-diketonato and N-oxide ligands on their thermometric properties. The investigated complexes are [Ln2(tta)6(pyrzMO)2] (Ln = Eu (1·C7H8), Gd (5)), [Ln2(dbm)6(pyrzMO)2] (Ln = Eu (2), Gd (6)), [Ln2(bta)6(pyrzMO)2] (Ln = Eu (3), Gd (7)), [Ln2(hfac)6(pyrzMO)3] (Ln = Eu (4), Gd (8)) (pyrzMO = pyrazine N-oxide, Htta = thenoyltrifluoroacetone, Hdbm = dibenzoylmethane, Hbta = benzoyltrifluoroacetone, Hhfac = hexafluoroacetylacetone, C7H8 = toluene), and their 4,4′-bipyridine N-oxide (bipyMO) analogues. Europium complexes emit a bright red light under UV radiation at room temperature, whose intensity displays a strong temperature (T) dependence between 223 and 373 K. This remarkable variation is exploited to develop a series of luminescent thermometers by using the integrated intensity of the 5D0 → 7F2 europium transition as the thermometric parameter (Δ). The effect of different β-diketonato and N-oxide ligands is investigated with particular regard to the shape of thermometer calibration (Δ vs T) and relative thermal sensitivity curves: i.e.. the change in Δ per degree of temperature variation usually indicated as Sr (% K–1). The thermometric properties are determined by the presence of two nonradiative deactivation channels, back energy transfer (BEnT) from Eu3+ to the ligand triplet levels and ligand to metal charge transfer (LMCT). In the complexes bearing tta and dbm ligands, whose triplet energy is ca. 20000 cm–1, both deactivation channels are active in the same temperature range, and both contribute to determine the thermometric properties. Conversely, with bta and hfac ligands the response of the europium luminescence to temperature variation is ruled by LMCT channels since the high triplet energy (>21400 cm–1) makes BEnT ineffective in the investigated temperature range.

Development and calibration of reduced-size plate thermometer for measuring incident heat flux

This study proposes a new reduced-size plate thermometer with a modified shape and improved insulation performance in order to resolve problems commonly found when using conventional plate thermometers to measure incident heat flux in fire environments, for example, a low spatial resolution caused by the large plate area and a non-uniform temperature distribution on the plate. The main results of this study showed that the new plate thermometer exhibits high spatial temperature uniformity, and that the plate thermometer can be reduced in size to 30 mm. Moreover, it was found that the relative error of the incident heat flux of the plate thermometer was substantially reduced compared to that of a heat flux meter using a conduction correction factor expressed as a third-order polynomial function of heat flux, rather than using an average empirical constant calculated from measurement over a wide range of heat fluxes. Finally, it was confirmed that the incident heat flux measured by the new reduced-size plate thermometer in a heptane pool fire was in good agreement with the heat flux meter measurements during the rapid-fire growth, fully developed and decay phases of a fire.

Interpolating Equation of Precision Platinum Resistance Thermometers in the Temperature Range between -80°C and 300 °C

This paper compares two interpolation equations for the calibration of precision platinum resistance thermometers (PPRTs) in the temperature range between -80°C and 300°C. They are the deviation function specified in the International Temperature Scale of 1990 (ITS-90), and the quadratic Callendar–van Dusen (CVD) equation. It was found that when the calibration range was between -80°C and 300 °C, ITS-90 deviation function resulted in a measurement error-of-fit of ±23mK, and the CVD equation resulted in ±24mK. In the temperature range of (-80∼0)°C, ITS-90 deviation function showed distinctly better performance than the CVD equation. When the temperature range was between 0°C and 100°C, the difference among the two equations was insignificant. In the temperature range of (100∼300)°C, the measurement error-of-fit of ITS-90 deviation function increased with temperature, and the maximum error-of fit under the CVD equation appeared at 200°C. If the temperature range is wider, the ITS-90 deviation function had better calibration effect. While the CVD equation worked better in a narrow temperature range.