What is ISO 22232‑3 about?  
ISO 22232‑3 specifies methods, tolerances, and acceptance criteria for verifying the performance of combined ultrasonic test equipment (i.e. instrument, probes, and cables connected) by the use of appropriate standard calibration blocks.
Note1: These methods are specifically intended for manual test equipment, i.e. ultrasonic instruments according to ISO 22232-1, and for manual ultrasonic non-destructive testing with single- or dual transducer probes according to ISO 22232-2. ISO 22232‑3 is also applicable for multi-channel instruments. For automated test equipment, different tests can be needed to ensure satisfactory performance.
Note2: The specified methods are intended for use by operators working under site or shop floor conditions.
Note3: These methods are not intended to prove the suitability of the equipment for particular applications.
Note4: ISO 22232‑3 excludes ultrasonic instruments for continuous waves. Note5: ISO 22232‑3 also excludes ultrasonic phased array systems, see e. g. ISO 18563-3. If a phased array instrument is used in combination with single- or dual-transducer probes, this document is applicable to this combination.
 Who is ISO 22232‑3 for? 
 ISO 22232‑3 on characterization and verification of ultrasonic test equipment is useful for: 
-  Testing equipment manufacturers 
- Testing companies 
- Companies holding tested materials 
- Quality control
- Engineers
Why should you use ISO 22232‑3?  
Ultrasonic test equipment uses high-frequency sound waves to measure the thickness or hardness of a material. Ultrasonic tests often are performed to assess corrosion on pipes, valves, and steel or aluminum constructions. An ultrasonic instrument is also used to detect flaws such as cracks and leaks.
The objective of the ultrasonic tests in ISO 22232‑3 is to provide the operator with a simple method that allows identifying deterioration in the performance of the combined equipment. These tests are only intended to monitor the continuing performance of a fixed combination of equipment that has been previously shown to operate satisfactorily.
