The temperature measurement of intermediate level nuclear waste containers is vital to monitor their long term condition. Thermal imaging has a number of advantages for this application compared to single spot radiation thermometers and as such it was selected to monitor intermediate level waste containers. In order to achieve a low measurement uncertainty a robust temperature calibration is required, and it is important to have a good level of confidence in the emissivity of the surface being measured. The infra-red emissivity of the container materials was therefore measured and corrected for. The third consideration is the impact of gamma radiation on the thermal imager and how any radiation damage will affect the measured temperature. The implementation of a calibrated instrument and emissivity correction was validated using temperature controlled, 1:10 scale model 3 m 3 box containers within a climatic chamber. The surface temperature of the scale containers was determined to an uncertainty of ± 6.5 °C ( k = 2.1) for the container walls, ± 3.5 °C ( k = 2.1) for the container lid and ± 1.5 °C ( k = 2.1) for the container vents. The radiation testing of multiple thermal imagers indicated no calibration drift due to radiation exposure and provided the maximum achievable lifetime in terms of total radiation dose, with this being 598 ± 35 Sv (k=2). The techniques used to operate within a gamma environment and determine the temperature of the 1:10 scale 3 m 3 box containers were therefore successful.

Abstract This study demonstrates the Electro-Thermal Mechanical Testing (ETMT) system's capability to analyze the thermo-mechanical behavior of Inconel 718 (IN718) at a heating rate of 5 °C/s, achieving temperatures up to 950 °C. The temperature profile peaks at the sample's center and is approximately 25 °C at the extremes. Upon reaching 950 °C, the sample was aged for 30 hours before being rapidly quenched. This process froze the microstructure, preserving the phase transformations that occurred at various temperatures across the temperature parabolic gradient, which resulted in a complex gradient microstructure, providing a comprehensive map of phase transformations in IN718. The integration of thermal measurement, COMSOL modeling, scanning electron microscopy enabled a thorough characterization of the microstructural evolution in IN718, linking observed phases to the specific temperatures which provided a rapid screening of the effect of using different heating treatment routes.

In this laboratory-based study, a plate was designed, manufactured and then characterised thermally and dimensionally using a thermal imager. This plate comprised a range of known scratch, dent, thinning and pitting artefacts as mimics of possible surface anomalies, as well as an arrangement of higher emissivity targets. The thermal and dimensional characterisation of this plate facilitated surface temperature determination. This was verified through thermal models and successful defect identification of the scratch and pitting artefacts at temperatures from 30 °C to 170 °C. These laboratory measurements demonstrated the feasibility of deploying in-situ thermal imaging to the thermal and dimensional characterisation of special nuclear material containers. Surface temperature determination demonstrated uncertainties from 1.0 °C to 6.8 °C (k=2). The principle challenges inhibiting successful deployment are a lack of suitable emissivity data and a robust defect identification algorithm suited to both static and transient datasets.

Many established nuclear power producing countries are currently decommissioning first and increasingly second-generation power producing plants and fuel processing facilities. This has led to a growing inventory of different containers and packages containing radioactive waste and other nuclear materials, as well as storage of spent fuel. Here we describe research to establish in-situ yet remote health monitoring techniques based on novel temperature measurement methods for different containers and racks used to hold different nuclear waste forms, special nuclear materials and spent fuel.

Aim To assess the usefulness of monthly thermography and standard foot care to reduce diabetic foot ulcer recurrence. Methods People with diabetes (n = 110), neuropathy and history of >= 1 foot ulcer participated in a single-blind multicentre clinical trial. Feet were imaged with a novel thermal imaging device (Diabetic Foot Ulcer Prevention System). Participants were randomized to intervention (active thermography + standard foot care) or control (blinded thermography + standard foot care) and were followed up monthly until ulcer recurrence or for 12 months. Foot thermograms of participants from the intervention group were assessed for hot spots (areas with temperature >= 2.2 degrees C higher than the corresponding contralateral site) and acted upon as per local standards. Results After 12 months, 62% of participants were ulcer-free in the intervention group and 56% in the control group. The odds ratios of ulcer recurrence (intervention vs control) were 0.82 (95% CI 0.38, 1.8; P = 0.62) and 0.55 (95% CI 0.21, 1.4; P = 0.22) in univariate and multivariate logistic regression analyses, respectively. The hazard ratios for the time to ulcer recurrence (intervention vs control) were 0.84 (95% CI 0.45, 1.6; P = 0.58) and 0.67 (95% CI 0.34, 1.3; P = 0.24) in univariate and multivariate Cox regression analyses, respectively. Conclusions Monthly intervention with thermal imaging did not result in a significant reduction in ulcer recurrence rate or increased ulcer-free survival in this cohort at high risk of foot ulcers. This trial has, however, informed the design of a refined study with longer follow-up and group stratification, further aiming to assess the efficacy of thermography to reduce ulcer recurrence.

Intermediate level nuclear waste must be stored until it is safe for permanent disposal. Temperature monitoring of waste packages is important to the nuclear decommissioning industry to support management of each package. Phosphor thermometry and thermal imaging have been used to monitor the temperature of intermediate level waste containers within the expected range of environmental storage conditions at the Sellafield Ltd site: temperatures from 10 C to 25 C and relative humidities from 60 feasibility of determining internal temperature from external surface temperature measurement in the required range of environmental conditions has been demonstrated.

Intermediate level waste containers are used for the storage of an assortment of radioactive waste. This waste is heat-generating and needs monitoring and so this work was undertaken to determine whether the mean internal container temperature can be inferred from the temperature of the vent. By using two independent thermometry techniques, phosphor thermometry and thermal imaging, the internal temperature was demonstrated to be proportional to the vent temperature as measured by both methods. The correlation is linear and given suitable characterisation could provide robust indication of the internal bulk temperature.

Thermal imaging is a useful modality for identifying preulcerative lesions (“hot spots”) in diabetic foot patients. Despite its recognised potential, at present, there is no readily available instrument for routine podiatric assessment of patients at risk. To address this need, a novel thermal imaging system was recently developed. This paper reports the reliability of this device for temperature assessment of healthy feet.

In this paper a description is given of the development, characterisation and first results of a thermal imaging device aimed at significantly reducing the incidence of diabetic foot ulceration (DFU). These devices will be used in three clinical centres and in two preliminary clinical trials. The first will be on healthy volunteers to set a robust baseline for the overall research aims and the second on  >100 patients at high risk of DFU. In the second phase of the project the objective is to demonstrate significant reduction in the incidence of DFU through a comparison of the results of standard care of high risk feet with standard care plus thermal imaging.

The number of thermal imagers being used for absolute temperature measurement in industry has increased dramatically in the past few years. Due to this it is vital that we have a greater understanding of the performance and limitations of thermal imagers for manufacturing, design and calibration purposes, in particular for applications where they are being used for quantitative temperature measurements. A metrological assessment of six thermal imagers was carried out over their full temperature range using the National Physical Laboratory (NPL) high performance standard blackbody reference sources to identify their accuracy and repeatability. The size-of-source effect, temperature drift due to warm up, image non-uniformity, effects of ambient temperature changes and distance effects were also investigated. Results show that temperature errors for five out of the six imagers fell outside of the manufacturers’ stated uncertainty at a distance of 1.0 m from the blackbody reference source. Additionally, a number of the imagers showed poor performance with regard to image non-uniformity, drift, size of source and distance effects. This has implications when the imagers are used for in situations where accurate temperature measurements or temperature differences are required.

Medical thermography has become ever more accessible to hospitals, medical research, and clinical centers with the new generation of thermal cameras, which are easier to use and lower in cost. Some diagnostic techniques using thermal cameras are now regarded as standardized, such as the cold challenge test for Raynaud’s phenomenon. The future for medical thermography appears to be improved accuracy, standardization, and establishment as a mainstream medical imaging methodology. Medical thermography standardization, quantitative measurements, image comparison, and multi-center research trials all require thermal cameras to provide a demonstrably traceable, accurate, and reliable temperature output. To this end, the National Physical Laboratory (NPL) has developed a multi-fixed-point source that serves as an in-image calibration system, thereby providing a reliable means for radiometric image validation. An in-field-of-view fixed-point validation system for thermal imaging has successfully been developed, tested, and validated at NPL and has undergone field trials at three clinical centers in the UK. The sources use the phase change plateaux of gallium–zinc eutectic, gallium, and ethylene carbonate. The fixed-point sources have an estimated cavity emissivity of greater than 0.998, a plateau longevity of nominally 3 h at ambient conditions, a stability of 0.1°C, or better, over that period, a repeatability of 0.1°C or better, and an estimated temperature uncertainty of  ±0.4°C (k = 2). In this article, the source specifications and design as well as testing, validation, and field trial results are described in detail.

Patient temperature is a fundamental physiological measurement used primarily for observation and diagnosis, for example during surgery, intensive care, recuperation, or treatment. A variety of thermometers are used clinically and these can be separated into two categories, either contact (oral thermometers, rectal thermometers and temporal strips), or non-contact (ear thermometers, temporal thermometers and thermal imagers). To have the maximum confidence in the clinical performance of the temperature measurement instrument it is strongly desirable that the device be traceably calibrated to the International Temperature Scale of 1990 (ITS-90). Lack of traceable calibrations accredited to ISO17025 can lead to unreliability in temperature measurement and in some cases can have a deleterious effect on patient care. The National Physical Laboratory (NPL) maintains and disseminates the ITS-90 for contact and non-contact thermometry in the UK. The importance of accredited traceable calibrations and an outline of contact and non-contact thermometry standards are given here.