GE DXR250V, DXR250P, DXR250RT, DXR250, DXR500L Operating Manual

18th World Conference on Nondestructive Testing, 16-20 April 2012, Durban, South Africa

Field Radiography with Advanced Digital Detector Arrays

(DDAs): Improving Safety & Speed

Shana M. TELESZ 1, Juan Mario GOMEZ

1

GE Inspection Technologies; 50 Industrial Park

1559; [e-mail]; [e-mail]

Rd,

Lewistown, PA 17044-9312 US; Phone: [phone]

Abstract
Over recent months, large strides have been made in application development and utilization of Digital
Detector Arrays (DDAs) in field radiography environments. The use of DDAs in aerospace aircraft assembly
and many oil and gas applications from upstream insulated pipes to midstream flow lines and downstream
valves inspe ction have proven to significantly red uce exposure times ver sus film and computed radiography
techniques. This substantial reduction in exposure time not only increases productivity, but also improves
safety by decreasing the time the radiation source has to be exposed as well as in some cases allows for a
decrease in source strengt h.

The astonishing reductions in exposure times are enabled by the core design concepts of DDA technology,
original developed for medical applications. Many of the same design principals to protect doctors and patients
from radiation exposure by optimizing not only image quality but ensuring the all x-rays are captured and
utilized efficiently to create the image. By leveraging the core technology from the medical industry with some
industrial specific modifications, the DDA has proven to be a viable and advantageo us inspec tion tool for field
applications.

Keywords: Digital Detector Array (DDA), oil and gas, aerospace.

1

1. Introduction

Over recent months large strides have been made in application development and utilization of
Digital Detector Arrays (DDAs) in field radiography environments. The use of DDAs for this
applications show benefits of significantly reduced exposure times versus traditional film and
computed radiography techniques. These results are enabled by the technology investment and
focus of the medical image quality to achieve image quality, but with respect to dose. Unlike
cabinet based radiography, where dose is less important as humans are shielded from the x-ray
exposure; field and medical applications must take this into greater consideration. This was a
major factor in DDA design and choices for photodiodes, scintillator and display electronics.

2. Applicati ons and Enabling Technolog y

2.1 Application Development and Utilization

Applications development efforts over recent months have led to the wide acceptance and use of
DDAs for field inspection, an application previously limited to film and computed radiograph y
techniques. These application development efforts have included and proven successful
implementation in a wide range of field applications from both the oil and gas and aerospace
industries. In both industries, significant reductions in exposure times have been realized by

utilizing DDAs for radiographic inspection versus traditional film and computed radiography
techniques. The reduction in exposure time not only enables productivity through shorter shot
times, instant availability of images for review and analysis; but also improves overall safety to
radiation workers and other employees by decreasing radiation source deployment or on-time
and in some cases allows for a decrease in energy or source strength.

2.1.1 Application Example
There are many examples where DDAs have shown significant benefits over film or
computed radiography. One of these examples is in the oil and gas downstream inspection
of valves. The same inspection plan was completed utilizing both computed radiography
and a DDA. The image quality results were similar or improved utilizing the DDA, but the
exposure time results were remarkably reduced.

Figure 1: Two application examples showing comparing DDA and CR exposure times

2.2 History of DDA Innovation

The medical industry began developing DDA technology over 25 years ago, spending
millions of dollars in the initial 10-year development cycle. Since initial introduction,
technology investment has continued, focusing on two critical areas: image quality for
visualization of relevant features and dose reduction for improved doctor, healthcare
worker, and patient safety. The focus on optimization of image quality with respect to
dose is one of the key aspects leading to the successful implementation into industrial field
applications, where radiation safety is a critical consideration versus environments where
shielding and radiation protection cabinets can be utilized.

2.3 DDA Design Considerations