Diagnostic techniques for the monitoring and control of practical flames

In this article, the theoretical and experimental aspects of three active thermography approaches: pulsed thermography (PT), lock-in thermography (LT), and vibrothermography (VT), are discussed in relation to the nondestructive evaluation (NDE) of honeycomb sandwich structures. For this purpose, two standard specimens with simulated defects (delaminations, core unbonds, excessive adhesive, and crushed core) were tested, and results were processed, examined, and compared. As will be pointed out, the similarities and differences between these active approaches allow conclusions to be made about the most suitable approach for a particular application. In addition, results from NDE inspection by X-rays and c-scan ultrasounds are provided and discussed for reference.

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Comparative Study of Active Thermography Techniques for the Nondestructive Evaluation of Honeycomb Structures

Thermal imaging (TI) is an emerging, non-invasive process analytical technique suitable for the food industry. While TI was originally developed for military applications, it has recently emerged as a powerful non-destructive measurement technique in other industries. This paper provides an overview of TI theory, equipment, and image processing. Recent advances and potential applications of TI for food safety and quality assessment such as temperature validation, bruise and foreign body detection and grain quality evaluation are reviewed.

Applications of thermal imaging in food quality and safety assessment

Eddy current pulsed thermography (ECPT) is an emerging nondestructive testing and evaluation (NDT&E) technique and has been applied for a wide range of conductive materials. In this paper, a single-channel blind source separation is proposed to process the ECPT image sequences. The proposed method enables: 1) automatically extract valuable spatial and time patterns according to the whole transient response behavior without any training knowledge, 2) automatically identify defect patterns and quantify the defects, and 3) to provide guidelines of choosing the optimal contrast functions that can improve the separation results. In this paper, both mathematical and physical models are discussed and linked. The basis of the selection of separated spatial and time patterns is also presented. In addition, an artificial slot and a thermal fatigue natural crack are applied to validate the proposed method.

Automatic Defect Identification of Eddy Current Pulsed Thermography Using Single Channel Blind Source Separation

Pulsed thermography for non-destructive evaluation and damage growth monitoring of bonded repairs

http://muscle.ercim.eu/images/DocumentPDF/MP_333_A0-15-2004.pdf

Statistical analysis of IR thermographic sequences by PCA

An IR image processing approach for characterising combustion instability

Electronic noses, instruments for automatic recognition of odours, are typically composed of an array of partially selective sensors, a sampling system, a data acquisition device and a data processing system. For the purpose of evaluating the quality of olive oil, an electronic nose based on an array of conducting polymer sensors capable of discriminating olive oil aromas was developed. The selection of suitable pattern recognition techniques for a particular application can enhance the performance of electronic noses. Therefore, an advanced neural recognition algorithm for improving the measurement capability of the device was designed and implemented. This method combines multivariate statistical analysis and a hierarchical neural-network architecture based on self-organizing maps and error back-propagation. The complete system was tested using samples composed of characteristic olive oil aromatic components in refined olive oil. The results obtained have shown that this approach is effective in grouping aromas into different categories representative of their chemical structure.

M. Chimenti

Papers

Statistical analysis of IR thermographic sequences by PCA

An IR image processing approach for characterising combustion instability

A neural approach for improving the measurement capability of an electronic nose