Digital Detector Array 

DDA Digital Detector Array – is an electronic device that converts ionising radiation into a discrete array of analogue signals, which are subsequently digitised and transferred to a computer for display as a digital image corresponding to the radiation energy pattern imparted upon the device. It offers an alternative to the use of radiographic film and involves one less process step than CR (see ‘What the Hec?!’ CR & DR, November 2011) in that it does not produce an intermediate image that is subsequently digitised. With careful selection of parameters and calibration, DDAs can produce an image that is comparable or even better than that produced by film. As it is a digital image it can be manipulated with software to assist the operator in the analysis.

DDAs can range in speed from many minutes per image to many images per second. They are sensitive to dust, humidity and temperature and so have not found widespread use in the field. However, they are suited to fixed facility operations where they are generally used in air-conditioned cabinets.

For more information on DDAs see:
ASTM E2736 – 10. Standard guide for digital detector array radiology
ASTM E2698 – 10. Standard practice for radiological examination using digital detector arrays

What the hec?! articles are not intended to be the definitive account on the topic or acronym in question. Readers’ comments and contributions are welcomed. Email: ndtnews@bindt.org