Types of Ultrasonic Calibration Block

Has it always been a concern for you to determine the type of calibration block suitable for your inspection needs? This need can sometimes be disturbing.

But then again, let’s better understand what calibration blocks in ultrasonic testing are, and then we’ll consider how many types of calibration blocks there are.

Calibration blocks are used to assess and refine the correctness of measurement equipment. These calibration blocks come in different sizes and shapes, and the type of calibration block to be deployed is dependent on the application and the shape and form of the tested object.

Let’s take it up a notch as we enlighten you more, ready when you are.

What is a Calibration Block for UT?

Calibration and reference standard blocks are ultrasonic testing applications employed daily in ultrasonic testing. And this is the process whereby the accuracy and precision of equipment deployed are tested.

A great deal of ultrasonic equipment is utilized in several applications. This is why the inspection personnel should calibrate the equipment to befit the current requirement at the point of testing. In this process, calibrating the equipment settings will be necessary, the set-up test, and the transducer to ensure flawless accuracy and correctness.

These calibration blocks are usually available in different shapes and sizes according to the test being carried out and the application to be deployed. But furthermore, many ultrasonic calibration blocks utilize drilled holes and notches, which are bigger and do not depict actual defects.

Without wasting any more time, let’s consider the types of ultrasonic calibration blocks there are.

Ultrasonic Calibration Block Types 

• UT V1 Block Calibration: The V1 UT block calibration is an ultrasonic flaw detector calibration block used in ultrasonic testing to determine the quality of welded joints. This calibration block assists in determining the resolution capacity of ultrasonic straight-beam probes and the non-testing area (by steel) for straight-beam probes.

• UT V2 Block Calibration: This is also an ultrasonic flaw detector deployed in ultrasonic testing of welded joint’s quality. It is responsible for checking the probe points of sound waves in steel. It also permits the calibrating of the defect detector scan by sound velocity when testing is operational with straight-beam probes and angle beam probes.

• 5 Step Calibration Block: This steel Calibration Block is characterized by 5 steps alongside imperial and metric measurement marks that can be used to calibrate and verify ultrasonic thickness gauges. This type of calibration block helps measure the density and the dimension of a test object

• 10 Step Calibration Block: A 10 step calibration block is a special calibration block because it measures more density and dimension. Its scale ranges from two-point zero millimeters to twenty points zero millimeters. It is either made of steel, aluminum, or stainless steel.

• ASME Ultrasonic Calibration Blocks: ASME ultrasonic calibration blocks are perfectly suitable for piping inspection. It is an Angle Beam Calibration Block that contains (4) EDM notches (axial and circumferential) on both OD (Outer Dimension) and ID (Inner Dimensions) at a depth of 8-11% of nominal wall thickness x 1/4 max wide (most notches are approximately .020 – .030 wide) x 1.000 min long. 

• IIW Type 1 Calibration Block: The simple meaning the acronym IIW stands for is the International Institute of Welding, and this type of calibration block is available for inspection purposes due to its fashioned or fabricated design. IIW Type Calibration Block can be procured on the market in dissimilar materials. IIW type of calibration blocks can comprise extra calibration features such as notches, circular groves, and scales to meet specific application requirements.

• IIW Type 2 Calibration Block: This is a revised version of the main IIW-Type 1 design, which Includes a 2.0″ radius x .250″ deep cut-out enwrapped on the 4.0″ radius for distance calibration. It also includes numbers 3, 5, and 8 via holes (3/64″, 5/64″ AND 8/64″ diameter) and distance calibration marks to the 2.0″ hole. In compliance with the International Institute of Welding and ASTM E164.

• TOFD Calibration Block: Time of flight diffraction (TOFD) is an ultrasonic testing method utilized for volumetric testing of welds. And because of its precise sizing capability, it is extensively employed for pipeline Automated Ultrasonic Testing (AUT) and pressure vessels. This technique, however, is confronted by certain limitations. Most importantly, limitations relating to coverage.

• SC Calibration Block: This type of ultrasonic calibration block is an AWS-type block deployed for shear wave sensitivity calibration inspection. It consists of two .062″ diameter holes and complies with ASTM E164 and BRR/AWS stipulated conditions and requirements.

• DSC Calibration Block: The AWS-DSC Block calculates and inspects for distance, sensitivity, beam index calibration for angle beam transducers, and refracted angle, and it complies with AWS and ASHTO conditions. It ensures the calibration of alternate and longitudinal wave span, setting alignment for the sound beam spot of incidence, spread angle, and sensitivity.

• DC Calibration Block: The DC calibration block is an AWS-type block employed to determine a test material’s shear wave distance calibration. The DC AWS Block is a metal track interspace and beam exit point calibration standard. It measures distance, sensitivity, beam index calibration for angle beam transducers, and refracted beam in similarity with the DSC calibration block.

• RC Calibration Block: The AWS Resolution Calibration Block is employed to assess angle beam transducers’ resolution capacities. It consists of three sets of 0.0625″ diameter through-holes for 45°, 60°, and 70°, and made with complete compliance with AWS Welding Highway and Railway Bridges provisions D2.0 and Structural Welding Code ANSI/AWS D1.1.

UT Calibration Block for Piping

You should outline and identify several considerations when selecting a piping calibration block. From all the types of ultrasonic testing calibration blocks identified above, the most appropriate UT calibration block for piping is the ASME ultrasonic calibration block. You may ask why, but it is clear to everyone that this type of block is manufactured explicitly for this purpose alone.

The ASME ultrasonic calibration block is the perfect type of calibration bock to be deployed when inspecting a pipe because it is an angle beam calibration block that consists of four electro-discharge machining (EDM) notches (axial and circumferential) on both the Inner Dimension (ID), and on the Outer Dimension (OD) likewise.

It is necessary to deploy the precise fit for the right perimeter and thickness. It is also illogical to carry about all the diameters and thickness of pipe size calibration blocks. It would be a lot to carry around every time there’s an inspection.

UT Calibration Block for Aircraft Parts

The testing of aircraft parts is also paramount as they are responsible for transporting life and cargo from place to place. Therefore, the calibration blocks deployed at different stages for different parts may vary due to the many details involved in making an aircraft.

Consequently, in identifying what ultrasonic testing calibration block would be appropriate for aircraft parts, considering the types examined above, the IIW type calibration block or the miniature angle beam (ROMPAS Calibration Block) is the most likely calibration block to be administered to aircraft parts testing. 

The IIW type blocks are of two types with a mini-block type as well, and some of its functions are to calibrate devices for angle beam and regular incident inspections. It is also used to set metal distance and sensitivity, ascertain sound exit point and refracted angle for angle beam transducers, and estimate typical beam inspection depth resolution.

UT Calibration Block for Railway System

Several testing techniques are also to be considered when it comes to ultrasonic testing for railway systems. Ultrasonic flaw detection systems are an option, but two main calibration blocks that perform similar functions are considered with calibration blocks.

The V1 ultrasonic testing calibration block is an ultrasonic flaw detector calibration block applied in ultrasonic testing to determine the quality of welded joints. This calibration block aids or supports ascertaining the resolution capability of ultrasonic straight-beam probes and the non-testing area (by steel) for straight-beam probes.

And secondly, another calibration block that performs similar duties is the V2 block calibration. This is also an ultrasonic flaw detector deployed in ultrasonic testing of the welded joint to determine the quality of such welded joints. It is liable for checking the probe spots of sound waves in steel. It also permits the calibration of the defect detector scan by sound velocity when testing is operational with straight-beam probes and angle beam probes.

UT Calibration for Automotive Casting

If you have been closely observing, you will notice that different calibration blocks have been selected for different ultrasonic testing methods for all the categories of the various fields of testing that have been highlighted in this outline. Finally, we’ll look at ultrasonic testing calibration blocks for automotive casting.

For this testing category, the most suitable ultrasonic calibration block to deploy is the step and tapered calibration wedges, as steps characterize this type of calibration block and imperial and metric measurement marks used to calibrate and verify ultrasonic thickness gauges. This type of calibration block helps measure a test object’s density and dimension and is most applicable for detecting casting defects.

Steps and tapered calibration blocks come in a diversity of sizes and designs. Step blocks are usually produced in four or five-step variations. Still, when custom blocks are requested, they can be manufactured in as many specified steps determined by the required standard for inspection. Tapered blocks have a constant taper over the preferred density.

➤ Related Article: Calibration Methods and Calibration Blocks in Ultrasonic Testing

Conclusion

A quick recap identifies that calibration blocks are used to assess and refine measurement equipment’s correctness, and these calibration blocks come in various sizes and shapes. The type of calibration block to be deployed depends on the application and the shape and form of the test object.

Furthermore, calibration block types are numerous, and the different types available are for different testing forms. A few mentioned include Distance/Sensitivity Calibration, IIW Type Calibration Block, Resolution Calibration, etc. 

The different industries that rely on these calibration blocks for their different inspection aims were also identified. And a few of the mentioned industries also includes calibration blocks for aircraft parts, calibration blocks for the railway system, and lastly, calibration blocks for automotive casting.

And this is where we draw the curtains now, and we hope we have been of great help in your search for knowledge on the ‘Types of Ultrasonic Testing Calibration Blocks. In addition, here’s the top ultrasonic calibration block manufacturers for you to choose from if you plan to purchase.