Ground penetrating radar is used to detect unseen objects in the ground, concrete structures, and other non-metallic materials. It works very similar to a fish finder. It is used by emitting a pulse of radio waves into the test material, and it records the echoes as a picture similar to the one above. GPR is used in many areas such as construction, roadways, archaeology, mining, and more.
Construction companies often request GPR services. Before digging an area for building foundations, they need to know what is underground. GPR is able to identify if there are utility wires and pipes they need to avoid. Construction companies also test during construction for quality control purposes. They want to make sure everything is done correctly. If structural rebar was placed in a concrete structure, they will use GPR to see if the rebar was placed correctly. Another area where construction companies use GPR is to identify electrical wiring and pipes in walls and floors of buildings which they are adding on to.
GPR is increasingly being used to test roads for thickness, voids, and cracks beneath the surface. Voids and cracks in roadways usually lead to potholes, which nobody likes. Through the use of GPR, workers are able to identify what areas of road need repaired before there is a pothole.
Archeology would be very expensive if the only way they were able to identify historical areas was through digging into the ground. GPR maps the subsurface, and archeologists are able to identify areas of interest without digging. GPR is used to identify artifacts, historical building remains, unmarked graves, and historical sites.
GPR can be used to address numerous challenges associated with mining. Structural mapping, and tunneling and safety hazards can be identified through the use of GPR. Miners benefit from the ability to see into the ground; they can avoid loose rock collapsing and structural safety hazards.
A few days ago, I went into the field for the first time to see what a typical day was like for an NDT technician. I learned about safety, testing methods, and how we interact with the clients.
The place I went to was a compressor station. The first thing I had to do was put on the proper clothing and gear. I had steel toe boots, flame resistant coveralls, safety glasses, and the best was my pink hardhat. My coworker pointed out the windsock to me. If anything bad were to happen on the compressor station we would want to be upwind from it, and the windsock points to which direction the wind is blowing.
While we were there we performed two different testing methods, phased array and magnetic particle testing. When using phased array, we first put a lubricant on the weld so the phased array machine would move around easily. On the screen it is all light blue, but when there is an indication it is dark blue. Larger indications show on the screen as reds, yellows, and oranges, but we did not find any large indications that day. When black lines show up on the screen, it means we are moving the phased array machine too quickly. It did not take much time at all to test a weld with phased array, and the workers were able to continue their work right next to us. My coworker explained the advantages of using phased array over radiography. With radiography, we would have had to section off a large area, and the workers would not be able to continue their work in the area. It would also take longer to set everything up, about 20 minutes for each weld. Radiography also puts all workers at risk in the area by using radiation to test the welds. The use of phased array allows our client to save time, eliminate shut down costs, and avoid radiation hazards.
The second testing method we used was magnetic particle testing. It is used to find surface indications of the weld. The welds we tested were corner welds in tight places; we would not be able to use the phased array on these welds. With magnetic particle testing we have a two prong device which must be four inches apart. One prong goes on each side of the weld, and we put fine metal shaving dust on the weld. The dust is magnetized by the probes and will find its way into cracks or indications on the weld. This testing method was also quick and workers were still able to continue their work alongside us.
When were were done testing we went into the office to do paperwork for our client. We documented everything we found during testing and reported that no welds were rejected- they were all good. We printed out all documentation to give to the client and put it on a disk for their records. Speaking with the client reminded me of how I would interact with customers when I worked at a bowling alley. We do anything to make sure they are satisfied, and we do our best to work with them.
At the end of the day, I was very tired. I have more respect for the people who do work like that every day. I would take the opportunity to go out into the field again in the future because there is always more to learn. I plan to take what I learned to help me better market the company.
A drone is also known as an unmanned aerial vehicle. They are like high tech remote controlled helicopters which we attach cameras to. AER uses drones to increase safety and minimize our client's costs.
How do drones help us test? Some objects that we test are in hard to reach areas. Technicians have has to crawl in pipes or up tall ladders, which is a safety hazard to our workers. With the use of drones technicians can fly it into a pipe or up a tall building in construction to test and to identify areas that need further examination. Drones minimize the amount of time that technicians are in hazardous situations.
When we need to test in hard to reach areas, we sometimes need to set up tall ladders and scaffolding. The client whom we are testing for would need to stop the work going on in that area in order for us to set everything up and test. The client would be losing revenues by stopping production. AER is able to avoid the costs of lost production by utilizing drones to test the hard to reach areas.
Technology allows AER to increase our worker's safety and decrease our client's work stoppages. How do you use new technology to your benefit?
Hello! My name is Melanie Boop, and I am the Communication Specialist at AER.