What are the Common Types of Ultrasonic Calibration Blocks?

Ultrasonic Calibration Blocks

What are Ultrasonic Calibration Blocks?

A calibration block is a benchmarking device used to verify the correctness of the error level in flaw-detection equipment. A calibration block is a must-have tool for quality testers who are continuously checking the accuracy of defect detectors. Calibration checks are frequently performed on a daily, weekly, monthly, and yearly basis. The reason for this is because flaw-detecting devices acquire faults over time. Because of the increasing frequency of operation, a defect detector might amass a large amount of error in a short period of time, and an inspector must be aware of this.

What are the Common Types of Ultrasonic Calibration Blocks?

There are various types of ultrasonic calibration blocks categorized based on different standards including AWS (American Welding Society), IIW (International Institute of Welding), and ASTM (American Society for Testing and Materials) Distance/Area-Amplitude blocks. Here are some of the most popular ultrasonic calibration blocks.

  • IIW block – This type of ultrasonic calibration block is used for calibrating flaw detectors in specific uses especially during welding inspections to ascertain its quality. Also, they are very effective for determining the ultrasonic X-value and ultrasonic oscillation by first defining the index points all within an error accuracy of ± 0.5 mm. Furthermore, V1 ultrasonic calibration blocks help in choosing resolution capacity and non-testing zones for straight beams and the horizontal sweep for ultrasonic testers and flaw detectors.
  • V-2 block– An ultrasonic calibration block V2 fundamentally calibrates flaw detectors using sound velocity while using straight beam or angle beam probes. The V2 ultrasonic calibration Block is used to calibrate fault detection equipment, particularly those used in welding examination and quality evaluation. Naturally, it has longitudinal wave velocities of 5890 and 5950 m/s for a block material frequency of 5MHz and a temperature range of 15 to 25 degrees Celsius. It also features a shear wave velocity of 3240 and 3270 m/s for a 5MHz block material frequency and a temperature range of 15 to 25 degrees Celsius. It also allows for the measurement of the probe angle of sound waves in steel.
  • 5-Step block– When employing Ultrasonic Thickness Gauges or Flaw Detectors, the 5-Step Calibration Block is utilized for thickness and linearity calibration.  While it can be made from several materials, one of the most popular materials used for the 5-step ultrasonic calibration block is steel. The steps often increase at 2.5mm intervals to guarantee the proper calibration of equipment.
  • 10-step – The 10-Step ultrasonic calibration block is a special step block for calibrating thickness and linearity. It ranges from 2.0mm to 20.0mm in steps of 2.0mm and is also available in 2.5mm to 25.00mm. Like the 5-step ultrasonic calibration block it can be made with different materials including carbon steel, aluminum, stainless steel etc.


The importance of ultrasonic calibration blocks cannot be overemphasized as they ensure that flaw detectors retain a high level of precision in measurement and accurate readings. However, knowing the different types of ultrasonic calibration blocks available is also essential in choosing the most suitable calibration block for your use.

NDT-KITS is a leading Chinese Calibration Block Manufacturer of various types of calibration blocks with a strong commitment to quality and value delivery. With many years of industry experience and a team of highly qualified and experienced individuals, NDT-KITS can help you achieve your calibration objectives at very competitive prices. NDT-KITS track record of successful deliveries and satisfied customers both locally and internationally says it all. 

Disclaimer: This article contains sponsored marketing content. It is intended for promotional purposes and should not be considered as an endorsement or recommendation by our website. Readers are encouraged to conduct their own research and exercise their own judgment before making any decisions based on the information provided in this article.


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