Draft:Radiometric Profiling

Summary
Radiometric Profiling (RP) is a non-contact, rapid, real-time non-destructive testing technique that can be applied to any material. This application measures changes in a beam of gamma-ray energy as it passes through the sample being tested. The beam source is positioned on one side of the sample with the detector on the other side of the sample, measuring everything between the source and detector.

This method is unique in that it can accurately test bare and insulated material, including in-process piping, as-is. The low-level gamma-ray allows for personnel to be present while testing; there is no radiation risk or required safe work area designations.

How to Use
Radiometric Profiling is applied with the Lixi Profiler, a hand-held tool connected to a portable computer with proprietary technology for recording captured data. The subject is scanned with the arm (available in multiple sizes to accommodate different subject diameters) of the Lixi Profiler.

The operating technician can use different scanning techniques to achieve different desired outcomes. The two (2) most common techniques, slice scan and axial scan, are typically used to measure or find indications of degradation, abnormalities, liquid levels, blockages, or hidden pipe components. A slice scan is perpendicular, it reads and collects data across the axis of the subject. An axial scan is parallel, it reads and collects data along the centerline of the subject.

Calibration of the equipment to a known material standard converts the amount of radiation (light) received into a meaningful density measurement.

RP can be applied to:

 * Samples with a diameter of ½ to 24
 * Pipe with wall thicknesses of up to ¾''
 * Any material, length, run, straight line, or direction change of a structure or object including elbows, tees, reducers, and any other pipe or structural component

How it Works
Radiometric Profiling measures the attenuation of a highly collimated radiation beam, with a very small radioisotope of Gadolinium-153 as an energy source, directed at a specialized detector. It then converts gamma rays to visible light in the form of photons. The detection system measures the transmitted photons and compares the results against a calibration scale.

Material is introduced between the energy source and an energy detector. The detector measures the amount of energy passing through the material (displayed as counts) and a pre-defined calibration allows for the conversion of detector measurements into calibrated values typically expressed in units compatible with the material being tested. The more material being measured the lower the counts and the higher the calibrated value. There is an inverse relationship between detector readings and the calibrated values.

For example, if a corroded area is scanned over with the Lixi Profiler, then the scan will reflect a loss of density equivalent to the loss of steel. For example, if a pit 2.50mm deep is scanned over, the Profiler will show a reduction in the graph from 21.50 mm to 19.00mm Assuming that the insulation and product density have not changed over a short distance, the only cause for a reduction in the graph would be loss from the metal pipe.

Uses / Application
Radiometric Profiling (RP) can be applied to any material, though is most commonly used to test the mechanical integrity of industrial steel piping. Other current applications include locating and measuring defects in metal support structures, timber bridges, copper tubing, high density polyethylene (HDPE) plastic, and fiberglass reinforced plastic (FRP) piping.

RP can locate/detect the following on bare material or material under insulation:


 * Fouling and blockages due to sludge, mineral deposits, debris, or other matter
 * Welds
 * Moisture
 * Corrosion
 * Erosion
 * Position of gates in gate valves
 * Components including injection nozzles, thermocouples, etc.
 * Stuck cleaning pigs
 * Changes in pipe schedule

RP can measure the following on bare material or material under insulation:


 * Thinning material / material loss; i.e. Pipe wall loss due to Corrosion Under Insulation (CUI) or High Temperature Sulfidation Corrosion (HTSC)
 * Remaining material; i.e. remaining pipe wall thickness
 * Material change; i.e. percentage loss on pipe wall versus nominal thickness
 * Internal and external pitting
 * Moisture in insulation
 * Liquid levels in vertical and horizontal pipe

Features
Advantages
 * Highly accurate; 2% to 7% accuracy
 * Pipe with a diameter as small as ½” can be accurately tested
 * Pipe with wall thickness up to ¾” can be tested
 * Indications as small as ¼'' in diameter are easily detected
 * It does not require a radiation safety barrier. It poses no radiation exposure risk liability to company personnel, and can be legally and safely performed during normal operation.
 * No removal of insulation is necessary; the accuracy of results is not impacted by insulation
 * There is zero contact required to test the subject
 * Can test suspended and closely nested structures and piping
 * Can test straight pipe and metal structures, elbows, tees, reducers, and any other pipe or structural component
 * Will not interfere with plant instrumentation (level gages, etc.)
 * Is not impacted by interferences of other nearby metals
 * Not affected by temperature of piping
 * Tests the entire circumference of the pipe or structure (instead of just a single spot or side)
 * Averages 150+/- test locations per day
 * Real-time results

Disadvantages


 * Above a combined thickness of 30mm wall it becomes difficult to detect smaller defects and due to excess noise.
 * As the thickness of the steel increases (above 25 mm) the radiation attenuation variability increases and therefore affects the sensitivity of the system.
 * Requires trained and skilled technician to operate
 * Limited to testing subjects under 24” in diameter

Equipment
The Lixi Profiler, a hand-held portable device, utilizes the physics of Radiometric Profiling. The Profiler has proven to be an excellent tool for detecting CUI, High Temperature Sulfidation Corrosion (HTSC), moisture in insulation, liquid levels in piping, verifying if gate valves are fully open, and more.

The Lixi Profiler is configured for conventional or rope access use, light weight, and battery operated for complete portability. The tool is assembled, calibrated, and ready to use within minutes by a trained and skilled technician. The low-level gamma radiation source is approved for on-person air travel.



A Lixi Profiler system includes :


 * Detector Module: Detector handle 15 lbs., (2) Detector assembly cable, Detector extension assembly cable
 * Rugged Purpose Built Computer: 11” x 8” x 1.5”, 2.5 lbs. Aluminum case, 5.5” x 4” Daylight readable screen, (2) Computer cables, UniConnect module, USB keyboard
 * TG-41 Source Holder Device: Source holder padlock with (2) keys, Source holder allen wrench, Gd-153 (up to 1.3 Ci) sealed source, UN2911 Excepted Pkg.
 * Battery Brick: 8” x 5” x 3”, 6 lbs., 190 Wh of power for a long day of use, Battery charger & AC power cord, (2) Battery brick cables
 * C-arms and assembly: 18 inch C-arm (2) allen screws; 13 inch C-arm (2) allen screws, 6 inch C-arm with (2) allen screws, C-arm allen wrench
 * Rugged Carrying/Shipping Case: 2 Keys, 26” x 19” x 16”, 65 lbs. with contents

History
Lixi, Inc. was incorporated April 18, 1978 as an Illinois corporation to manufacture, sell, distribute and service the LixiScope. The name LIXI is actually an acronym for Low Intensity X-ray Imaging. The LixiScope and its technology are based in U.S. Patent 4,142,101 which was assigned to the National Aeronautics and Space Administration (NASA) as a result of their initial investment in research and development activities to bring the LixiScope to market. NASA grants Lixi Research Limited Partnership a partially exclusive license for the isotope version of the LixiScope on November 29, 1982.

Lixi, Inc. receives approval from the U.S. Nuclear Regulatory Commission (NRC) in 1985 to distribute the LixiScope to licensed users in the industrial and medical markets. The U.S. Food and Drug Administration grants Lixi, Inc. permission to market the LixiScope for medical use. Lixi's industrial x-ray tube version is registered with the FDA in accordance with the Code of Federal Regulations.

The company establishes a domestic medical and industrial domestic network and operates internationally through distributors and original equipment manufacturers. Lixi’s customers include AT&T, RCA, Texas Instruments, Hughes, Xerox, General Motors, General Electric, Motorola, TRW, Intel, Ford and General Dynamics.

In February of 1986, Lixi, Inc. loans five instruments to the FDA to investigate the Tylenol (bottle tampering) poisonings.

August 1986, Lixi, Inc. introduces its Microfocus x-ray system for the surface mount device inspection market. Lixi, Inc. also begins to provide peripheral equipment and accessories due to customer demand for complete turnkey systems.

In 1989, the Swedish Mt. Everest Expedition Team brings the LixiScope on its expedition to render proper medical care previously unavailable in remote areas.

In 1996, the American Petroleum Institute (API), through the Petroleum Environmental Research Forum (PERF), funded a project via a grant to Lixi. The intent was to develop a device that was very portable and hand-held, with technology that could identify the presence of corrosion under insulation in real time. This project was completed with the production of the Lixi Profiler in 1998.

Lixi's real-time x-ray systems, which have been used in the United States and abroad for quality assurance inspection of small components and the mechanical integrity of piping and structures are rated superior to similar instruments made by other manufacturers.

Additional Reading
Gadolinium-153