Nondestructive Testing (NDT) and Field Services
NDTech is a consulting firm offering a wide variety of Nondestructive Testing (NDT) consulting, training, products, and field services. We maintain expertise in all major NDT inspection methods, including Ultrasonic, Radiography, Penetrant, Magnetic Particle, Eddy Current, Acoustic Emission, Thermal Analysis, and Visual Testing.
ASNT Training & Certification
NDTech is a certified Level III source for ASNT TC-1A courses in UT, RT, MT, and PT. Custom tailored courses for review, familiarization, and management overview in these areas are also available. In addition, NDTech can provide training in Eddy Current, Acoustic Emission, and Visual Inspection.
RV ULTRASOUND, managed by Bob Harris, formerly of HARISONIC LABORATORIES, specializes in providing custom ultrasonic transducers to satisfy specific industry requirements. RV Ultrasound search unit designs are based on more than 35 years of experience in developing transducers having the optimum performance for flaw detection and material evaluation as can be attested to by the many past and current satisfied users.
NDTech has designed and manufactured a number of specialized NDT products. With our engineering experience and production facilities, we can develop the tools or parts you need for your unique testing situations.
Failure of radiant tubes in a hydrodesulfurization furnace promoted the development of an ultrasonic technique for detecting the presence of polythionic acid stress corrosion cracks in the austenitic stainless steel tubes in these furnaces. The initial hand-scanning ultrasonic method was too slow for complete furnace inspection in the time available. In order to reduce the time required for inspection, a semi-automated UT tool was designed and fabricated.
The following laboratory instrumentation were used for development work and are in excellent condition. Please contact us if you are interested in any of these items, indicating the number of the product you are interested in.
Ampex model FR-1300. Portable 14 channel 1″ magnetic tape recorder. Complete with preamps, record/reproduce modules for 6 tape speeds from 60 to 1 7/8 ips in FM, Direct, or PDM methods.
Honeywell model UGR Video Graphics Recorder. Produces continuous tone images from static video sources.
Houston Instrument model 6452. X, Y, Y’, 11″ x 17″ pen recorder.
Prototype 10 channel acoustic emission main frame signal conditioning unit. Also available with: magnetic held sensors and preamplifiers.
NDTech will periodically publish a newsletter covering brief descriptions of some useful but less publicized nondestructive testing instruments, techniques, and methods.
Let’s take a trip to Physics101; today we will be discussing the benefits of eddy current or rather the practical applications of it. So what is eddy current? Eddy current is the continuous electric current that is created as a direct result of altering the magnetic field within conductors. The simple way to define it would be to imagine loops of current created due to reversing the magnetic effect within the current creating conductor. So why is there so much talk about eddy current? Well many experts believe that with more research and development, eddy current can greatly benefit human race in a number of different fields. Without further ado, let’s kick things off.
- Braking Systems
Braking systems are often mechanical in nature, and due to the mechanical nature of the braking system, it can be seen that a lot of force is applied at certain points causing an increase in the amount of strain and stress at those points. So to reduce localised stress as a result of braking, eddy current is used. Since there is no contact per say between the braking system and the eddy current, there is no stress or strain that is created. But a completely flawless system is far off dream and needs countless hours of research and millions of dollars in funding to create a system that utilises just eddy current for braking purposes. At present the best we can hope for is to have a mix of eddy current and mechanical systems working in tandem to be sturdy as well as free of localised stress.
- Identify the Fake
Eddy current has been successfully used to identify the type of metal that is being introduced into an object. This benefit has resulted in the use of eddy current in vending machines. Vending machines are used around the world and they work on the principle of utilising a coin or two to pay for the product that was on display. The biggest reason why vending machines took so longs to become a part of offices and entertainment spaces around the world is because there was a flaw in the system that allowed users to use fake coins to get what they wanted. But with the introduction of eddy current that flaw was rectified and now almost all vending machines use eddy current for that exact purpose. It is to be noted that eddy current is not only used in vending machines, but is also used in the identification of fake slugs. Weapon manufacturers are more difficult to convince when it comes to newer technology, but they easily accepted the use of eddy current to ensure that fake slugs do not leave the factories under any circumstance.
Ultrasonic, vibrations of frequencies more noteworthy than the upper limit of the audible range for humans that is, more noteworthy than around 20 kilohertz. The term sonic is connected to ultrasound waves of high amplitudes. Hyper sound, at times called praetersound or microsound, is sound waves of frequencies more prominent than 1013 hertz.
At such high frequencies it is extremely troublesome for a sound wave to proliferate productively; for sure, over a recurrence of around 1.25 × 1013 hertz it is inconceivable for longitudinal waves to spread by any stretch of the imagination, even in a liquid or a solid, because the molecules of the material in which the waves are voyaging can’t pass the vibration along quickly enough.
Numerous creatures can hear sounds in the human ultrasonic recurrence run. A presumed sensitivity of roaches and rodents to frequencies in the 40 kilohertz region has prompted the fabricate of “pest controllers” that discharge noisy sounds in that recurrence range to push the pests away, yet they don’t seem to function as publicized.
Sounds in the range 20-100kHz are generally used for communication and navigation by bats, dolphins, and some different species. Significantly higher frequencies, in the range 1-20 MHz, are used for medical ultrasound. Such sounds are delivered by ultrasonic transducers. A wide assortment of medical analytic applications use both the echo time and the Doppler move of the reflected sounds to gauge the separation to internal organs and structures and the speed of movement of those structures.
Commonplace is the echocardiogram, in which a moving picture of the heart’s activity is created in video frame with false hues to demonstrate the speed and direction of blood flow and heart valve movements. Ultrasound imaging near the surface of the body is fit for resolutions not lesser than a millimeter.
The resolution diminishes with the profundity of penetration since lower frequencies must be used (the attenuation of the waves in tissue runs up with increasing recurrence.) The use of longer wavelengths suggests lower resolution since the most extreme resolution of any imaging procedure is proportional to the wavelength of the imaging wave.
An Ultrasonic sensor is a device that can measure the distance to any object by utilizing sound waves. It measures distance by conveying a sound wave at a specific frequency and tuning in for that sound wave to jump back. By recording the elapsed time between the sound wave being generated and the sound wave skipping back, it is conceivable to ascertain the distance between the sonar sensor and the question.
Since it is known that sound travels through air at around 344 m/s (1129 ft/s), you can set aside the ideal opportunity for the sound wave to return and multiply it by 344 meters (or 1129 feet) to locate the aggregate round-trip distance of the sound wave. Round-trip implies that the sound wave voyaged 2 times the distance to the object before it was detected by the sensor; it incorporates the journey from the sonar sensor to the object and the travel from the object to the Ultrasonic sensor.
Over the years, Radiography has played a very important role in the field of medicine and has allowed professionals all around the world to diagnose patients based on x-rays.
Radiography makes use of science that includes radiation in order to produce images of organs, tissues and bones that furthermore assists with the diagnosis and treatment of those conditions. These images are created by equipment that takes images deep inside the body that gets retrieved as x-rays.
The importance of these images cannot be stressed enough as it allows for medical professionals to know exactly what’s wrong with their patients. Could you imagine if someone had a tumour in their brain and the only thing a surgeon or specialist had to diagnose his patient was his/her symptoms? It would’ve been absolute chaos, to say the least, and would most certainly lead to a lot of misdiagnoses.
Radiography is thus very important and is used daily to come up with a treatment plan to treat severe cases of both tumours and cancers. The doctor that specializes in radiography is referred to as a radiologist and his/her assistant is referred to as a radiologic technologist.
The Specialty of becoming a Radiologist
A qualified radiologist has to finish their Associate’s degree in radiology, which after him/her can become either radiologists or radiologic technologists. The median salary for such an occupation concludes to between $55,870 and $77,000.
As a very important part of radiography and a medical personnel team, radiologists specialize in different types of radiology that include diagnostic radiology, radiation oncology, paediatric radiology, nuclear radiation, pain medicine, neuroradiology and vascular and interventional radiology.
Apart from studying to become a radiologist, the same degree could qualify for entering different fields such as becoming a cardiovascular technologist, nuclear medicine technologist, as well as a diagnostic medical sonographer.
Becoming a radiologic technologist is a medical professional that forms part of a medical team and falls under the field of being responsible for the capturing of diagnostic imagery, as well as performing radiation therapy treatments that follow the diagnostic imagery. A radiologic technologist is trained as experts to perform patient positioning, specialize in anatomy, follow through with equipment protocols, have knowledge on radiation safety, radiation protection, as well as patient care.
The Importance of Radiology in a Hospital
When it comes to a hospital and the internal structure of its medicinal practice and staff members, radiology is regarded as the cornerstone of any hospital in the world. The creation of high-quality images allows for professionals to understand what their being dealt with, help them learn more about the human body and medicine, as well as how to treat different cases and deliver a healthy patient for check out at the end of the day. Radiology has evolved immensely over the years and has saved the lives of many all across the globe.
Ultrasonics refers to the study of the applications of sound waves that are at a higher frequency than the range which humans can hear. Most of the humans can hear up to 20 kHz, and ultrasonic waves have a frequency which is much higher than 20 kHz. Such waves are used in many fields such as navigations, medicine, imaging, cleaning, communication, mixing etc. The following are some of such real-life applications for ultrasonic waves:
Ultrasound is used to clean substances like glass, ceramics, metals etc. It is also used to remove grease and oil from the surface of such materials. Big industries use ultrasound to clean their machines and other apparatus. It is also used to remove oil and other lubricants from aircraft and even automobiles.
Detection of cracks:
One of the best ways to figure out if your structure has cracks or not, is to use ultrasound and check for echo patterns. Ultrasound is used to detect cracks in metallic compounds, and this is mainly used during the construction of huge bridges, buildings and other structures. The ultrasound waves produce distinctive echo patters when it hits the structure, and through software analysis, you can easily find out if there is a crack in the metal structure.
Echocardiography is often known as Cardiac echo which is basically the sonogram of the heart. The procedure is used for the diagnosis of heart diseases. Echocardiography is one of the most widely used diagnostic tests by cardiologists. You get information about the size of the heart, location, pumping capacity etc.
Using ultrasound, you can also get the images of other internal body structures such as organs, muscles and joints. The images that are got from ultrasound are known as sonograms. The images are got when the ultrasound echoes off the tissue and these echoes are recorded and displayed on the screen as an image.
Sound navigation and ranging have been one of the most popular methods which are used when they go underwater. SONAR makes it easy to communicate or detect objects that are under the surface of the water. SONAR is also used for robot navigations in the air and studies are going on to use ultrasound waves for atmospheric navigation.
Echolocation is when sound waves and echoes are used to determine if there are any objects in the space. Bats use the method of Echolocation to move from one place to another as they cannot see. They send out waves, and when the waves hit an object, it returns and signals them to move in another direction. Based on the nature of the echo bats will be able to determine the size and shape of the object that is in front of them.
The beauty about human existence is our ability to adapt. Extending from Darwinian theories which established human beings as the superior species for their innate nature of adaptation and natural selection to some of the most groundbreaking discoveries regarding anything under the sun, human beings have made the most of technology in every facet possible. Technology involves the gamut of inventions which have simplified human life and to that end, it has pervaded into every sphere. Inside homes which present some of the most spectacular and fascinating examples of technology and the gadgets that come along with it. When it comes to cleaning and sweeping, archaic forms of using buckets, mops and dusting cloths have been revolutionised into the ways of the present century through ultrasonic cleaning. Not as complicated as it sounds, the process becomes simpler and makes the tedious process of cleaning as easy as pie. Ultrasonic cleaning, simply defined is the process that uses an ultrasound and a cleaning solution or water to clean different objects. Minimising the time taken to clean using rudimentary methods, this process lasts about three to six minutes, but can go up till twenty depending upon the object. It is the complete removal of dirt, grime and other substances through the means of rapid, high frequency sound waves in a tank within which objects are immersed. The non audible rapid ultrasonic waves create a scrubbing action and with the aid of the cleaning solution, the objects within the tank are rendered clean. As simple as it sounds, it can be used for cleaning a wide variety of objects, mostly ones during cleaning which we break into a sweat. Initially, these machines were used in jewellery workshops, electronic repair workshops and other establishments, but of late, they have made their presence into households and made lives much easier. From jewellery to lenses, fountain pens to coins, golf clubs to window blinds, these machines clean it all and you don’t have to bat an eye. While the process of cleaning involves a few technicalities, it becomes easier to comprehend once you’ve formed a concept of it in your mind.
The process begins through the means of high frequency electrical energy that is converted by a transducer into high frequency sound waves which becomes ultrasonic energy. This energy then enters the liquid which causes small bubbles to form on the surface. These bubbles then travel rapidly inside the tank and implode on the surface of the object that is immersed within the tank. As soon as the bubbles burst against the surface, the cleaning solution then rushes in and cleans out all the nooks and crannies. This process keeps getting repeated on and on and bubbles are created and destroyed while the cleaning solution removes all the layers of dirt from the object. The scrubbing action of the water and the cleaning solution, the energy produced by the transducer and the bubbles that keep forming on the surface are the means through which cleaning happens. So when intricate and precious items get soiled and dirty, the ultrasonic cleaner comes to the rescue and does all your tedious work for you.
Radiography is one of the greatest advancements in science, especially in the field of medicine. But radiography is not restricted to the field of medicine alone as we have industrial radiography as well that is used for a lot of purposes apart from that of the medical needs, and that is why radiography came as a solution to a lot of problems and requirements that were existing in different fields. We have always had shallow knowledge when it comes to radiography, and that is why we are going to dig a little deeper and explore a lot of facts.
History of radiography:
Roentgen was the first person to theoretically and practically propound the theory of radiography. His invention of radiography came as a solution to a lot of problems that didn’t exist earlier. Almost all the people, be it a common man or a science professional, were interested in the idea and that is how it later got developed b incorporating latest scientific advancements.
Types of Radiography:
- Radiography is simply an imaging technique. It is the process of turning the image of a physical object on to a sheet of paper for further study and use. That is why radiography gained a lot of significance. Because an idea of that sort never existed earlier before Roentgen could put his head to use. This process that uses x-rays is divided into two categories, and they are, computed radiography and projectional radiography.
- The primary difference between the two lies in the type of image that comes as output. While in computed radiography the images are turned into 2D images, in projectional radiography it turns into 3D images. Both types of results have their own significance, and it depends on the field in which it is used. To our amazement, these techniques are also used in airport security checking.
- Apart from this, we should also remember that industrial radiography is also present and that is a separate subject that we have to talk about. Though we primarily classified radiography as computed and projectional based on the results that they give, we must remember that there are a lot of variations in radiography such as fluoroscopy, angiography, contrast radiography, absorptiometry and much more.
Benefits of radiography:
- One of the major places where radiography is used is in the field of medicine, and that is the reason as to why we are sticking to that.
- It gives scope for better medical management and also makes sure that patients are benefited out of it.
- It is one of the harmless methods of scanning, and it gives scope for identifying even some of the toughest diseases of the world.
Testing equipment is used to ensure the quality and the life of a product. These test tools are classified into the destructive types and the non-destructive types. The non-destructive test equipment is largely used in sectors where specimen checking is impossible and in cases where if the product is damaged the consequences are irrecoverable.
Concrete is one common area where the non-destructive testing tools are largely used. These tools can be highly useful as concrete is one of the places where tools that damage the product cannot be used to ensure its quality. So non-destructive tools are used in the process of testing the quality. However, in the process of testing, the structure and the type of concrete should be known in order to carry out the testing process perfectly. Listed below are some of the common tools that are a part of the non-destructive testing equipment.
Concrete Strength testers:
The first tool on the list is, in fact, the most important one as well. This non-destructive tool helps in finding out the strength of the concrete, and it can be done at varying degrees with the help of advanced tools that are available in an extensive range.
Ultrasonic concrete tester:
Ultrasonic devices are also a part of the non-destructive test equipment. These instruments either generate stress waves or sound waves that are used to determine the quality of the other materials that are used as a part of the concrete with destroying the basic structure.
Two things have to be kept in mind as far as concrete basements or flooring is concerned. Concrete has steel bars within them, and not all concretes are corrosion resistant. So as these corrosion testers ensure both the quality of the steel bars within concrete and also the corrosion resistance of the concrete.
Rebar locators are exclusively used to measure the quality of the reinforcing bars present within the concrete. Once the construction begins to take shape, it might be difficult to ascertain the quality of the steel bar within. Rebar locators make the job easy and testify the quality of the steel bars inside the concrete.
Moisture and Flow testers:
A lot of construction materials are involved in the process of concrete. The quality and the moisture content of every single component involved will play a role in the standard of the concrete. So these moisture testers ensure the quality of the materials used as a part of the concrete thereby determining the final quality of the building.
Ultrasonic Pulse velocity meter:
Just like the concrete testing tool that was used in the beginning process, pulse velocity meter is used after the construction of the building is wound up. This instrument also employs ultrasonic waves to test the quality, uniformity, porosity and the placement of the concrete in the building. This will ensure the safety and the life of the building.
To know how thermal analysis works it is important that we understand what thermal analysis is and where it is used. Thermal Analysis influences that part of science that deals with materials. There are almost 11 known types of thermal analysis. Depending on the situation and the material that is about to undergo the test these thermal analyses are classified. In the process of thermal analysis, the administer makes an effort to find how a material reacts at different temperatures. In simple terms change in material in correspondence with the change in temperature. This is the simple science behind the thermal analysis.
History and Scope of Thermal Analysis:
- It is quite interesting to note that thermal analysis came into existence during the BC days. This is because most of the changes that natural sciences dealt with were with regard to fire. So they regarded fire as the basic matter that propelled change within two physical quantities.
- Keeping the above point in mind, the sciences that followed also employed fire as the considered it as the general analyzer of matter. However, they kept redefining the word fire with words like heat and temperature.
- Thermal Analysis is primarily used in the pharmaceutical industry. So it has to be either a chemist or a pharmacist who will possibly be handling the thermal analysis procedures.
- Usage of thermal analysis is widely used in the chemical industry. This is because the change in the reaction between two materials can be monitored quickly be a chemist only with the fluctuation in temperature.
- Almost all the studies carried out in the purview of thermal analysis can be classified into three major heads. They are Mass, Temperature or other parameters such as dimensions, etc. Depending what head the materials fall into, the method of thermal analysis is chosen.
- There is also a concept called Simultaneous Thermal Analysis where the method enables the application of two processes such as a thermal analysis and a differential scanning calorimetry on the same material, at the same time and also in the same instrument.
- The common application of thermal analysis is found in pharmaceutical materials, polymer, metal, food and printed circuit boards
Now that you have gotten a basic idea of what is thermal analysis, let us see how the process works:
Process of thermal analysis:
- Thermal Analysis begins with finding the right method that has to be applied to the material that is undergoing the test.
- Once the suitable method is found, the next thing is to apply the same onto the materials. A set of tools and instruments are required to carry out the process. Once you have the things set, you can get to the process of thermal analysis.
- At varying degrees of heat, the material is tested, and the corresponding changes are recorded along with the results. The point at which the material is found to give the required result is what we find through the thermal analysis.
Radiography is a technique that used the electromagnetic radiation to view the internal structure of an object. This is what happens with radiography. Radiography comes along with an X-ray generator. These X-rays are responsible for creating the electromagnetic radiation that pierces the body and scans whatever is inside. The images that are generated in radiography are all two-dimensional images. They are not elevated or superimposed. This is where the role of CT scanning technique enters. CT which expands as Computed tomography, brings in a set of these two-dimensional images processes it and then turns it into a three-dimensional image.
Now having spoken about the basic things about radiography, here is one confusion that prevails in the heads of most of the people. The confusion is as to, what is the difference between a radiologist and a radiographer. So let’s find out the difference between a radiographer and a radiologist.
A radiographer is a person who has knowledge of accessing the instruments along with radiography. They take care of patients and assist them in treatments that are associated with radiography. This is the job of a radiographer. Radiographers are doctors. They are simply medical technicians who are involved in the process of radiography. Radiographers play a role in different medical teams as in CT scan, Radiotherapy treatment, patient care, X-ray, and MRI. They can assist in the process of radiography and can carry out the whole, but they cannot interpret the results and suggest medication.
In contrary to the above, a radiologist is a doctor who has specialized skills in the field of radiography. A radiologist knows when and where radiography has to take place and the patient who is required to go through such treatment, while a radiographer can only tell you how to do it. Once the process of radiography is done, the radiologist can look at the result and interpret the status of the patient and suggest medication. This is the role of the radiologist in the process of radiography. Without the radiologist, the process would stay incomplete.
Now we clearly know the difference between a radiographer and a radiologist. So it is pretty much vivid that both the professional are imperative for radiography. While one is sound with the machine and other is sound in the medical perspective making their roles significant.
In the recent times, the scope for both the radiographer and the radiologist has largely increased. There are certain degrees that a person has to complete in order to qualify himself as a radiographer. A lot of institutes today cater these courses that help a lot of upcoming aspirants in this profession.
Ultrasonic waves are those waves that have a range that is more than the upper limit of the audibility range of a normal human being. Which means the sound that is generated by the ultrasonic waves is not audible for the human ears. The word ‘ultrasonic’ is more often associated with hardware and engineering industry. But in reality, they play a significant role in the medical field as well.
Ultrasonic in industries:
- As far as the usage of the ultrasonic waves in the industrial sector is concerned, it plays a major role in the testing sector. It is one of the most common methods used in the non-destructive testing equipment.
- In case if you didn’t know about these testing methods, testing the quality of a product can be classified into destructive testing methods and non-destructive testing methods. Since we are restricting ourselves to the non-destructive testing methods, we will see what this non-destructive method is. In the process of assuring the quality of a product the manufacturers employ testing methods, and if these testing methods come out with results with affecting the product or damaging them, then they are known are non-destructive testing methods. So non-destructive testing has to do with Ultrasonic waves? Ultrasonic waves are also utilized by the industries to test the quality of the product and this testing falls under the non-destructive category.
- They analyze the product and give out the results without tampering the product. That is the reason why ultrasonic waves are associated with the non-destructive testing equipment. Most of the tools and equipment that are designed for the non-destructive testing purpose have the influence ultrasonic waves in them.
- This ultrasonic method is employed in areas where the inspection is critical, making it an important part of the industries.
- In industries that involve a lot of complex engineering as in the case of an aircraft, if damaged can be easily spotted and rectified with the help of ultrasonic waves. Prospectively dangerous situations can also be avoided as these methods in most cases are non-destructive and do not explore or exploit the other associated parts unless directed to do so. This makes rectification much easier than before. So this means, ultrasonic waves do not just stop with ensuring quality but also assists in rectifying the errors if any spotted.
- Apart from non-destructive testing, ultrasonic waves are used in drilling, welding, soldering, cutting and machinery, cleaning and sonar. So the usage of ultrasonic waves is pretty much versatile than we can imagine.
The process in which these waves work is simple. The medium that uses the waves s what that matters. It is simply the transmission of rays, and the rays reflect through the medium that they are sent through. They precisely act on the spot where checking or rectification is required, without damaging the system and the transmission gets back to the source from where it was earlier generated. This is the process involved in the industrial ultrasonic transmission.
NDTech maintains expertise in all major inspection methods including: