Calibration and performance evaluation of an uncooled infrared thermographic system (original) (raw)
Related papers
Uncooled photodetectors for infrared thermography
Proceedings of the 2000 International Conference on Quantitative InfraRed Thermography, 2000
An advanced photovoltaic detector is reported, based on monolithic Hg 1-x Cd x Te heterostructure with 3-D architecture. It operates in the MWIR or LWIR range at ambient temperature or under thermoelectrical cooling. Since the device operates at zero bias mode, it does not exhibit low frequency noise. The measurements show the possibility to achieve detectivity of 1•10 9 cmHz 1/2 /W at the 8-9 µm range. Potentially, the devices can be assembled in large focal plane arrays. This will enable obtaining a NETD of less than 0.1 K for staring thermal imagers operating with f/2 optics and 50/sec. frame rate.
Uncooled long wavelength infrared photon detectors
Infrared Physics & Technology, 2004
At present, uncooled thermal detector focal plane arrays are successfully used in staring thermal imagers. However, the performance of thermal detectors is modest, they suffer from slow response and they are not very useful in applications requiring multispectral detection.
Self-Calibrating Infrared Thermometer for Low-Temperature Measurement
IEEE Transactions on Instrumentation and Measurement, 2000
This paper presents a self-calibration technique for the removal of measurement errors caused by thermal gradients in thermopile-based infrared thermometry, particularly when measuring low temperatures. Applications for this self-calibration method include low-temperature measurement in the food industry and infrared thermometers for remote temperature monitoring in cold climates. The self-calibration technique reported in this paper is shown to reduce the measurement error to within ±1 • C within 5 s of an extreme thermal shock, compared with an uncompensated thermometer that does not recover until the thermal gradient is removed. The root-mean-square temperature noise for the duration of the thermal shock test is less than 0.2 • C. This technique is the subject of a patent application and can be applied to any infrared thermometer utilizing a thermopile, regardless of the thermopile size and geometry.
Infrared Thermography for Temperature Measurement and Non-Destructive Testing
The intensity of the infrared radiation emitted by objects is mainly a function of their temperature. In infrared thermography, this feature is used for multiple purposes: as a health indicator in medical applications, as a sign of malfunction in mechanical and electrical maintenance or as an indicator of heat loss in buildings. This paper presents a review of infrared thermography especially focused on two applications: temperature measurement and non-destructive testing, two of the main fields where infrared thermography-based sensors are used. A general introduction to infrared thermography and the common procedures for temperature measurement and non-destructive testing are presented. Furthermore, developments in these fields and recent advances are reviewed.
MAPAN, 2010
The non-contact measurement of temperature by using the emitted thermal radiation has been an innovative field of measurement science and fundamental physics for more than a hundred years. It saw the first highlight in Gustav Kirchhoff's principle of a blackbody with ideal emission characteristics and culminated in Max Planck's formulation of the law of thermal radiation, the so-called Planck's law, forming the foundation of quantum physics. A boost in accuracy was the development of semiconductor detectors and the cryogenic electrical substitution radiometer in the late 1970s. Semiconductor detectors, namely photodiodes, deliver an electrical current proportional to the absorbed optical radiation. Due to the measurements of thermal radiation over a wide range of temperature and wavelength, thermodynamic temperature measurements with radiometric methods have set benchmarks to all, the electrical, dimensional and optical metrology. The paper describes the measurement of the spectral responsivity of semiconductor detectors traceable to the SI units and their application for thermodynamic temperature measurement by the absolute measurement of thermal radiation using filter radiometers with calibrated spectral irradiance responsivity.
Review Infrared Thermography for Temperature Measurement and Non-Destructive Testing
2014
The intensity of the infrared radiation emitted by objects is mainly a function of their temperature. In infrared thermography, this feature is used for multiple purposes: as a health indicator in medical applications, as a sign of malfunction in mechanical and electrical maintenance or as an indicator of heat loss in buildings. This paper presents a review of infrared thermography especially focused on two applications: temperature measurement and non-destructive testing, two of the main fields where infrared thermography-based sensors are used. A general introduction to infrared thermography and the common procedures for temperature measurement and non-destructive testing are presented. Furthermore, developments in these fields and recent advances are reviewed.
ACR II: Improved absolute cryogenic radiometer for low background infrared calibrations
Applied Optics, 2005
A second-generation absolute cryogenic radiometer (ACR II) was developed for use at the Low Background Infrared calibration facility at the National Institute of Standards and Technology. The need for spectral calibrations of very sensitive ͓D* ϭ 10 14 cm ͑Hz͒ 1͞2 W Ϫ1 ͔ infrared detectors necessitated the use of a cryogenic infrared monochromator and a more sensitive radiometer. The improved low-power performance of the ACR II compared with the older absolute cryogenic radiometer (ACR) has also made it useful as the primary standard for the calibration of cryogenic blackbody sources that are used as low-power infrared sources. The responsivity of the new radiometer's receiver is 210 K͞mW with a type A (random component) standard uncertainty of at most 7 pW when making power measurements of less than 10 nW. The original ACR has a responsivity of 29 K͞mW and has a type A standard uncertainty of approximately 100 pW when making a similar low-noise-power measurement. Other properties of the radiometers are also described and compared.
A detector combining quantum and thermal primary radiometric standards in the same artefact
We present the concept of a dual-mode primary standard cryogenic detector, utilizing a predictable quantum efficient silicon photodiode, and demonstrate the behaviour of the detector from room temperature down to 30 K. The detector absorbs visible radiation generating either heat or photocurrent, dependent on the selected mode of operation. In effect, this detector links optical power to fundamental constants through the two different routes of operation in the one artefact. Forward biasing of the photodiode is used in lieu of resistive heating to provide the electrical substitution power. The detector has a thermal time constant of 50 s and a sensitivity of 1.39 K mW −1 . Using an LED source, we measure equivalence between the two modes of operation of 1.5% at 50 K, limited principally by our knowledge of the wavelength of the emitted radiation of the source.