PCTE Industrial

Do you know which technology is used to detect metallic discontinuity or detect cracks? 

Are you curious to know about the ultrasonic sensor? If yes, it is the Ultrasonic Testing technology used in several industries for various purposes. 

What is Ultrasonic Testing?

Ultrasonic testing is a non-destructive testing method that uses ultrasonic waves to detect anomalies in material. High-frequency ultrasonic wave is transmitted into the material to detect flaw. 

How does it work?

Ultrasonic testing uses piezoelectric transducer that transmit ultrasonic (sound) wave into the material and the reflected wave is received by the receiver. Time taken for the ultrasonic wave to travel into the material and reflected from the backwall is measured to determine the thickness of the material. Any discontinuities of wave in between are identified as flaws or defects. 

Transducers for wave transmission and detection

The transducer in an ultrasonic sensor that transmit ultrasonic wave is transmitter and that receive the wave is receiver.

Eight qualities of the Ultrasonic Testing

Able to determine thickness and estimate size and defects

Provide Immediate results upon testing 

High accuracy when compared to other NDT methods for determining flaws and depth

Non hazardous to personnel 

Sensitive to both surface and subsurface discontinuities 

High depth penetration to detect deeper flaw within the material 

Only one side access is required to perform testing 

Ultrasonic testing is a way to test material, to know more details about its internal state and details like thickness. It is a non-destructive testing method which the material does not get damaged or chipped when testing. The equipment used for this testing is the ultrasonic sensor. This device sends high-frequency sound waves into the material under investigation, and as the wave travels back, the time travelled is measured and deduced to its condition.

How does ultrasonic sensor work?

It has a transducer to emit high-frequency sound waves into the material under test. The frequency is much higher than the normal hearing range and can go up to 5000 kHz. These sound waves travel through layers and act only when they experience a change in medium or a defect. Upon striking a varied surface, the waves travel back to the source, an ultrasonic sensor.

The sensor records the time travelled from the sensor, to the material and return to the sensor. It also notes any change in its frequency. Experts study and analyze these reports to understand if there is a flaw in the specimen. The premium quality, feature-rich sensor also stores the records for future reference.

It is non-destructive

The ultrasonic sensor is a piece of equipment that falls under the category of non-destructive testing techniques. Unlike destructive methods, you wouldn't have to dig through the layers to measure the thickness. Moreover, there will not be any chipping of the topmost layer to identify the material or test its durability. You only have to place the sensor on the object to get the desired results.  

Perks of using the sensor

There are countless benefits of using the ultrasonic tester. Some of them are:

·       High penetration and sensitivity allow the deep detection and small flaw detection.

·       Can be used when only one side of the test material is accessible.

·       It provides reliable results to make remedial or repair decision.

·       Non-hazardous to surrounding personnel and operations.

In the end, it is fair to say that using an

ultrasonic sensor

Eddy current testing is known to be one of the many non-destructive testing methods that use the principle of electromagnetism to detect flaws in conductive materials. A special-designed coil energised using an alternating current is put in proximity to test the surface. It further generates an altering magnetic field, interacting with the test sample, producing eddy currents in the vicinity.

All the variations in the changing phases and the magnitude of such currents are then monitored with the use of receiver-coil. Sometimes, changes to the alternate current that flows in the primary excitation-coil are also measured in the process.

 Working of Eddy Current Testing

This process works on the principle of electromagnetic induction. When an alternating current passes through a conductor, the alternating magnetic field is developed around the coil. This field contracts and expands as the current falls and rises. If you bring the coil closer to another electric conductor, the fluctuating field surrounding the coil permeates the material, thereby inducing the eddy current flow in such conductor. After this, the eddy current itself develops its own magnetic field.

This second magnetic field so formed opposes the primary magnetic field, thereby affecting the current and voltage flowing throughout the coil. Any alterations in terms of the conductivity of the material are further examined throughout eddy current testing. The marked changes also affect the magnitude of eddy current, for instance, near-surface defects, differences in thickness, and others. There is always a greater flow of eddy current at the surface in high conductivity metals and a decrease in penetration in the metals like aluminum and copper.

 Benefits of Eddy Current Testing

·       Eddy current testing helps to detect surface and near-surface cracks.

·       It can also detect defects via several layers without inference from the planer defects.

·       A non-contact method during testing makes it possible to check high-temperature surfaces as well as underwater surfaces.

·       Eddy current testing provides immediate feedback to the project.

·       This type of testing is effective on all the test objects that have physically complicated geometries.

·       The preparation time is quick and hassle-free.

·       This testing can measure the electrical conductivity of test objects.

Stress corrosion cracking is a galvanic corrosion caused by the combined effect of tensile stress and corrosive environmental conditions. Detection of such corrosion's is possible well before it destroys the whole structure. Hence, it is repairable before it goes beyond restoration, or before the cost to restore breaks your bank.

Causes of Stress Corrosion Cracking

There are three main reasons due to which this cracking happens.

·       Applied stress

·       Increased temperature

·       Susceptible materials like chlorides and hydrogen sulphide

All these factors are required for the corrosion to occur. However, the conditions may vary depending on the material in question.

Minimizing the Peril Factors

Many companies plan and keep a regular check on the material to ensure it is not affected by stress corrosion cracking. The examinations are a regular thing so that defects (if any) can be detected well on time, as it is sometimes not visible with the naked eye. Other things that you can do to minimise their peril factors are:

Suitable Material

In many cases, stress cracking is avoidable by using a better quality suitable material. Also, avoid any tensile stress concentration occurring on the edges. Using better material, keeping in mind the environmental conditions and other factors, can save you from a lot of trouble.

Temperature

Studies show that cracking can occur at a temperature of around 60 degrees Celsius. However, the situation gets worst above 80 degrees Celsius. You can minimise the effects by controlling operating temperatures as well as the electrochemical potential of the alloy.

Cracking Type

Be aware of the cracking or corrosion that your metal or alloy is prone to. Two types are namely: chloride-induced and H2S induced. For chloride-induced cracking, it is advisable to use metals like stainless steel with considerably high nickel content. Whereas concerning the H2S induced cracking, high nickel content works well for almost all environmental conditions.

Videoscopes have indeed been a breakthrough in the field of industrial testing equipment. Also known as a video borescope, it performs the same function as an optical borescope. This enables inspectors to look inside the industrial machine. However, a videoscopefunctions in a completely different way and is more sophisticated. A videoscope consists of a rigid or semi-rigid cable with a small medical-grade camera attached at the end. By inserting the camera inside the machine, pipe, or any industrial machine, one can get visual outputs on a screen.

Modern videoscopes come with sophisticated features like snapshots, video recording with sound, a digital image processor, and joystick controller for the 360-degree probe. The latest probes deliver high-quality video output. The users can connect them directly to tablets and smartphones. The industries where a videoscope would be of great use are:

·         Oil and gas: Among the various industries, the oil and gas companies need to maintain some of the strictest standards. Therefore, videoscope is imperative for inspection of defects in pipes, turbines pressure vessels and asset components that are difficult to reach physically.

·         Power and energy: Videoscopes find considerable application in power plants producing conventional and renewable energy alike. A single snag in a power plant can shut down the entire power generation process, which would lead to huge losses. Using a videoscope, the inspectors can look for any damaged parts like turbine bladeand get it replaced before any major potentialdisruption takes place.

·         Manufacturing: Typically, manufacturing plants use various complex machinery, which includes moving parts. To ensure that the entire system works smoothly, experts need to carry out inspections and regular maintenance using videoscopes, ensure the integrity of the parts and components.

·         Aviation: Aircrafts require frequent safety inspections between flights. Using a videoscope, inspectors can perform inspection much quicker at hard to reach area like jet engine blade.

An ultrasonic transducer is a device that transforms some form of energy into an ultrasonic wave. There are a few different types, that are ordered by the source of the energy and by the substance of the intervening medium (like air), through which the waves act or is carried.

Mechanical devices consisting of gas-driven or pneumatic transducers like whistles, liquid-driven transducers, such as hydrodynamic oscillators, vibrating blades are usually limited for low ultrasonic frequencies. They are used in air circulation, ultrasonic cleaning, the addition of fuel oil into burners. While, electromechanical transducers like piezoelectric and magnetostrictive gadgets are more versatile.

However, the most sought-after ultrasonic transducer is the piezoelectric crystal as it can be promptly used over the complete frequency range and for all output types. Piezoelectric crystals generally contain quartz, Rochelle salt, and specialized varieties of ceramic.

Also, one can select sharply outlined designs for clearly identified applications. For instance, a circle-shaped piezoelectric ultrasonic transducer gives a plane ultrasonic wave.

Employment in research

Cavitation (the cycle of development of air bubbles) is one field where ultrasonics has had a monumental and meaningful influence. An ultrasonic wave can be utilized cautiously to regulate cavitation, thereby making ultrasound a helpful apparatus in the examination of this cycle.

Widespread sonar (sound navigation and ranging) usage in maritime activities and innovative applications

The wide-ranging employment of sonar in marine science is well-known. What is not known to many people are facts like employment of ultrasonic ranging devices in highly-developed fishing vessels to aid fishing.

Likewise, ultrasonic echolocation has been put into service in traffic control applications and in determining the number of things on an assembly line.

In addition, there is ultrasonic ranging, the underlying principle for eye and vision concepts for robots which has various significant therapeutic applications.

One more application of the ultrasonic methodology is in a formal investigation of structures in atomic reactors.

Ultrasonic thickness gaging is referred to as a non-destructive testing technique used in measuring the thickness of a material. An ultrasonic thickness gauge is fast, reliable, and versatile that only requires one side of the sample to measure its overall thickness.

 The first-ever ultrasonic thickness gauge was introduced in the year 1940s. This device is small and portable, and one can optimize it for a wide variety of test applications. The ultrasonic thickness gauge has undergone many changes in terms of its construction, technology, and ease of application.

 What could be measured using an ultrasonic thickness gauge?

Any common engineering material could be measured ultrasonically. This instrument could be set up for materials such as plastics, metals, composites, ceramics, fiberglass, and glass. In some cases, liquid levels and biological samples could also be measured using this instrument. Measuring the thickness using this device doesn't include destruction, cutting, or even sectioning of a material. The use of ultrasonic thickness gauge is very hassle-free and non-destructive. It is essential to mention that one cannot measure the thickness of the substances or materials such as foam, wood, paper, and concrete using an ultrasonic thickness gauge.

 Different types of ultrasonic thickness gauges:

One would come across two different types of ultrasonic thickness gauge, namely, corrosion gauge and a precision gauge. The former is all about measuring the wall thickness of the materials and substances such as pressure vessels, metal pipes, tanks, structural parts, etc., that are usually prone to internal corrosion and couldn't be seen from the outside. Precision gauges could be termed as single element transducers and are generally recommended for all the remaining applications such as the measurement of smooth metals and materials like composites, fiberglass, plastic, ceramics, rubber, etc. Compared to the former, precision gauges are more prevalent in their use, owing to their versatility.

Ultrasonic thickness gaging is referred to as a non-destructive testing technique used in measuring the thickness of a material. An ultrasonic thickness gauge is fast, reliable, and versatile that only requires one side of the sample to measure its overall thickness.

 The first-ever ultrasonic thickness gauge was introduced in the year 1940s. This device is small and portable, and one can optimize it for a wide variety of test applications. The ultrasonic thickness gauge has undergone many changes in terms of its construction, technology, and ease of application.

 What could be measured using an ultrasonic thickness gauge?

Any common engineering material could be measured ultrasonically. This instrument could be set up for materials such as plastics, metals, composites, ceramics, fiberglass, and glass. In some cases, liquid levels and biological samples could also be measured using this instrument. Measuring the thickness using this device doesn't include destruction, cutting, or even sectioning of a material. The use of ultrasonic thickness gauge is very hassle-free and non-destructive. It is essential to mention that one cannot measure the thickness of the substances or materials such as foam, wood, paper, and concrete using an ultrasonic thickness gauge.

 Different types of ultrasonic thickness gauges:

One would come across two different types of ultrasonic thickness gauge, namely, corrosion gauge and a precision gauge. The former is all about measuring the wall thickness of the materials and substances such as pressure vessels, metal pipes, tanks, structural parts, etc., that are usually prone to internal corrosion and couldn't be seen from the outside. Precision gauges could be termed as single element transducers and are generally recommended for all the remaining applications such as the measurement of smooth metals and materials like composites, fiberglass, plastic, ceramics, rubber, etc. Compared to the former, precision gauges are more prevalent in their use, owing to their versatility.

Inductive eddy current tends to play an essential role in conduction non-contact experiments for measuring the distance, vibration and position of objects. The results of these experiments remain unaffected by the target's final characteristics, or environmental contaminants. This means your results will be several times more accurate.

There are few protocols you can follow to increase the accuracy of these results further.

1.   Always be sure about the circuit type. For example, user uses Colpitts circuits where the sensor coil interacts with the target and generates results with the oscillator amplitude and frequency varying. There is balanced bridge circuit that relies on impedance. Choose the right circuit for your tests.

2.   Many times, people make mistake of keeping another metal near the target to be measured. This will affect the test outcomes. Always ensure that there are no metallic objects present near the target.

3.   Eddy current method is truly reliable; however, environmental conditions or changes can influence the final measurements. This means, the data in a polluted place, with more oxides in the air will be different from the results in a cleaner location.

4.   Temperature is also an influencing factor. This is a lesser-known detail about eddy current measurements. Taking readings without proper calibration and adjustments in the environment will cause errors. The best temperature for taking readings would be room-temperature. If the temperature changes, user need to calibrate.

5.   Having two more sensors close to each other will affect the electromagnetic fields. This interference affects the accuracy of the readings. This is known as cross-talk.

6.   Not paying close attention to the mounting can make a big difference in the results. The mounting fixture is extremely important. Keeping too many conductive materials around the mounting fixture will reduce the performance of your system.

The use of handheld hardness testers is done when the sample that needs to be tested cannot be brought out of the site and requires on-site testing. If the sample size is too big, you should be ideally looking at using portable hardness testers. Some of the tested materials include aluminium alloys and profiles, sheets, tubes, and copper and brass products.

To carry out a portable hardness test, unlike the conventional testing methods, the test piece is not required to be brought to the tester. On the contrary, it is the opposite that happens. The popular methods use either the Vickers-diamond tip or the rebound method.  

One of the other commonly used method to test the hardness of a test piece is abrasion testing. In this case, the tester consists of a rotating disk that moves against the test piece. The rate at which the sample starts to wear becomes a measure of its hardness.  

There are three types of abrasions – flat, edge and flex. Abrasion or wear rates need to be known in industrial applications to enhance the service life of certain parts of machinery. Abrasion testing is often done to ensure that the wear rate of the various parts is normal and to check if there is any abnormality that needs to be rectified. A portable hardness test is a reliable method of understanding the wear rate in materials and is hence quite widely used in different industries.

The hardness of a material is usually associated with the resistance to wear and tear or abrasion of the material. Therefore, in many industrial applications, a portable hardness test is carried out through the abrasion and erosion testing methods. Though the method is slower than the indentation tests, the resistance to abrasion still becomes a measure of how hard the material is.

The use of handheld hardness testers is done when the sample that needs to be tested cannot be brought out of the site and requires on-site testing. If the sample size is too big, you should be ideally looking at using portable hardness testers. Some of the tested materials include aluminium alloys and profiles, sheets, tubes, and copper and brass products. 

To carry out a portable hardness test, unlike the conventional testing methods, the test piece is not required to be brought to the tester. On the contrary, it is the opposite that happens. The popular methods use either the Vickers-diamond tip or the rebound method.  

One of the other commonly used method to test the hardness of a test piece is abrasion testing. In this case, the tester consists of a rotating disk that moves against the test piece. The rate at which the sample starts to wear becomes a measure of its hardness.  

There are three types of abrasions – flat, edge and flex. Abrasion or wear rates need to be known in industrial applications to enhance the service life of certain parts of machinery. Abrasion testing is often done to ensure that the wear rate of the various parts is normal and to check if there is any abnormality that needs to be rectified. A portable hardness test is a reliable method of understanding the wear rate in materials and is hence quite widely used in different industries. 

The hardness of a material is usually associated with the resistance to wear and tear or abrasion of the material. Therefore, in many industrial applications, a portable hardness test is carried out through the abrasion and erosion testing methods. Though the method is slower than the indentation tests, the resistance to abrasion still becomes a measure of how hard the material is. 

Ultrasonic Sensor

PCTE Industrial provides ultrasonic testing equipment which includes ultrasonic sensor and ultrasonic transducer. Visit website or contact them today, to get more information.

Videoscope

PCTE Industrial’s range of videoscopes includes IdealBorescope B, IdealBorescope G, IdealBorescope O. Call them at 08 9322 4020.

UV Lamp

PCTE Industrial offers UV lamp, UV light torch for sale. They are specialist in offering non-destructive testing equipment. Visit website or call them at 08 9322 4020.

Eddy Current Testing

PCTE Industrial’ eddy current testing equipment includes systems for eddy current, standard probes and speciality probes. Visit website or contact at 08 9322 4020.

Hardness Testing

PCTE Industrial’s hardness testing equipment range covers Equotip 550 Leeb, Equotip 550 UCI, Equotip 550 Rockwell and more. Contact them, for more details.