• In isotropic and homogeneous materials, elastic constants including Young’s modulus, Poisson’s ratio, shear modulus and bulk modulus can be nondestructively measured by measuring the longitudinal and shear wave velocities of the material. The most common technique used for measuring the elastic constants is the pulse-echo ultrasonic testing. Considering typical measurement uncertainties, an uncertainty of 1% or better can be achieved at PAUT for these measurements.

• Evaluation of the quality of adhesive bonding is an important issue in many industries who incorporate adhesive joints in their products. Different types of defect may appear in adhesive joints and various NDT techniques are available to detect them. The most common defects in an adhesive bonding are complete disbond, void, porosity, poor cohesive strength of the adhesive layer, and poor adhesive-adherend interfacial properties.
• Proper analysis of ultrasonic signals is important is important in testing adhesive bonds in order to avoid misinterpretation. Due to the nature of the pulse-echo ultrasonic tests and due to the need for minimum reflection of waves from the adhesive interface for a “good” bonding, high frequency transducers are usually used in order to maximize the absorption of energy by the adhesive.
• PAUT is well experienced in ultrasonic testing of adhesive joints. In this regards, we have provided services to many industries.

• Ultrasonic nondestructive testing has many industrial applications, such as flaw detection, measurement of acoustic properties, and thickness measurement. Before starting any ultrasonic measurement process, a “calibration” process needs to be done by using a standard reference block. A large variety of standard blocks are used in ultrasonic testing, the most common of which are IIW or V1 block, miniature of V2 block, step block, etc. To assure the reliability of the measurement/testing process, it is necessary that standard or special blocks be used.
• PAUT can carry out the design, manufacture, and delivery of any standard or special calibration block.

• The accurate in-situ measurement of part dimensions during fabrication is of much interest to the manufacturing industry. In thickness measurements, pulse-echo ultrasonic testing technique permits quick and reliable measurement of thickness without requiring access to both sides of a part. Accuracies as high as ±0.01 mm are achievable in many applications. Most engineering materials can be measured ultrasonically, including metals, plastics and glass, as well as liquid levels. Ultrasonic thickness measurement systems can be used for on-line or in-process measurements, such as extruded plastics, rolled metals.
• A wide variety of transducers with various acoustic characteristics are available at PAUT to meet the needs of industrial applications. Typically, lower frequencies are used to optimize penetration when measuring thick, highly attenuating materials, while higher frequencies are recommended to optimize resolution in thinner, non-attenuating materials.

• An important advantage of acoustic techniques over other methods is their ability to measure material properties without harming them. Longitudinal waves can propagate in gases, liquids, and solids but transverse (shear) waves can only propagate in solids. The measurement of ultrasonic wave velocities depends upon sending a wave (pulse) into the material of known thickness and measuring the time-of-flight (ToF) of the reflected echo.
• The procedure for measuring longitudinal and transverse wave velocities is based on a comparison of the test material with a reference sample whose velocities are known. This process has been fully developed at PAUT and measurements of wave velocity can be carried out with very high accuracy.

• Our training services provide the trainees with knowledge about: the basic principles of various NDT methods, discontinuities in different product forms, importance of NDT, limitations of NDT methods, NDT applications, NDT standards and codes.
• PAUT offers training courses in phased array technology. We are currently one of the very few training companies in the I.R. Iran offering such advanced ultrasonic training courses.

The surface hardness of industrial parts which are subject to high wear is usually treated by surface hardening processes. For hardened surfaces, it is desirable to know both the surface hardness and the depth of the hardened layer. PAUT has developed ultrasonic testing techniques to nondestructively measure the depth of the hardened surface layer. The technique is based on the detection of the transition between different polycrystalline structures due to their variation in backscattering characteristics. Increase of the grain size increases the backscattering of ultrasonic waves.

• Numerical methods of modeling wave propagation and ultrasonic inspection, are very useful in studying the influence of different parameters on complex geometries and media. Numerical methods such as finite element method may be used to simulate the propagation of ultrasonic waves in welds and any other specimens.
• The main purpose of this service at PAUT is to find appropriate ways for simulation of the wave propagation in a specimen subjected to ultrasonic nondestructive testing. Finite element or finite difference methods enable us to get adequate representation of this process.