What is probe delay in ultrasonic testing?

The rising flank corresponds to the time at which the electrical signal is on the crystal and starts the sound pulse. However, before it is fed to the surface of the test object it must travel through the protection layer of the probe (probe delay).

What is delay line ultrasonic?

The ultrasonic delay line is a thin layer of piezoelectric material used to produce a short, precise delay in an electrical signal. The electrical signal creates a mechanical vibration in the piezoelectric crystal that passes through the crystal and is converted back to an electrical signal.…

What is a delay line transducer?

Delay line transducers are single element broadband contact transducers designed specifically to incorporate a short piece of plastic or epoxy material in front of the transducer element. Delay lines can be contoured to match the surface geometry of a part and can also be used in high temperature applications.

What does a delay line do?

The delay line is an elementary functional unit which models acoustic propagation delay. It is a fundamental building block of both delay-effects processors and digital-waveguide synthesis models. The function of a delay line is to introduce a time delay between its input and output, as shown in Fig.

What are the advantages of delay line transducers?

Advantages: Heavily damped transducer combined with the use of a delay line provides excellent near surface resolution Higher transducer frequency improves resolution Improves the ability to measure thin materials or find small flaws while using the direct contact method Contouring available to fit curved parts

What is a delay line in an ultrasound?

Delay Line – A material (liquid or solid) placed in front of a transducer to cause a time delay between the initial pulse and the front surface reflection. Transducer – An electroacoustic or magnetoacoustic device containing an element for converting electrical energy into acoustical energy and vice versa. See search unit.

How big is a Olympus delay line transducer?

Loading… These high frequency, focused delay line transducers are compatible with any ultrasonic instrument capable of displaying a return echo at depths as low as .010 inches in steel. The typical range is approximately from .010 inches to 0.250 inches in steel.

Which is the Zero reference on the delay line?

The echo from the end of the delay line, or from the front surface of the test piece in immersion setups, is used as the zero reference for depth or distance measurements. (This echo is often referred to as the interface echo.)