Interpretation of the principle of the ultrasonic straight probe

The probe is an important part of the ultrasonic flaw detector, which can realize the mutual conversion between the electric signal and the acoustic signal;

It can also control the propagation direction of the ultrasonic wave and the degree of energy concentration. When changing the incident angle of the probe or changing the scattering angle of the ultrasonic wave;

The main energy of the sound wave can be injected into the medium from different angles or the directivity of the sound wave can be changed to improve the resolution.

According to the different types of ultrasonic waves, probes can be divided into longitudinal wave probes (also called straight probes, flat probes), shear wave probes (also called oblique probes , oblique angle probes ) and surface wave probes. There are several types of probes;

Depending on the method of detectionection of faults, there are probes for detecting contact faults and probes for detecting water faults.

In addition, the sound beam of some ultrasonic flaw detection probes is gathered into a point or line, called a focusing probe;

Some ultrasonic flaw detection probes have an incident angle. It can be modified, called a variable angle probe;

There are also probes specifically designed for certain flaw detection needs. faults, called special probes.

Straight probes are made of sockets, shells, protective films, piezoelectric pads, sound-absorbing materials, etc. Straight probe longitudinal wave testing usually detects steel plates, forgings and other raw materials or materials after normalizing.

The functions of the right probe components are as follows:

(1) The transmission/reception of ultrasonic waves is completed by piezoelectric chips;

(2) The protective film is made of high hardness corundum sheet, wear-resistant;

(3) Aluminum alloy shell, surface sandblasting/passive treatment;

(4) The sound-absorbing material is used to absorb the noise on the back of the chip;

(5) The socket is an interface of electrical signal, which is connected to the instrument via the probe line.

The method of scanning forgings when using straight probe longitudinal wave detection is as follows:

(1 ) Scanning range: the entire surface of the forging should be scanned continuously and completely.

(2) Sweep speed: The speed of movement of the probe must not exceed 150 mm/s.

(3) Scan coverage must be greater than 15% of the diameterof the probe.

(4) When the detection thickness of the forging is more than 400mm, it should be detected from the two opposite ends.

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