JPS59180317A - Ultrasonic thickness measuring probe - Google Patents

Abstract

PURPOSE:To allow a probe to abut on a body to be measured easily and to reduce a measurement error by inserting a magnet into the outside ring of the probe. CONSTITUTION:The external ring body 12 covers the probe 1 and the magnet 8 is incorporated therein to stick to carbon steel piping by magnetic force when contacting the external surface of the piping. The magnet 8 is surrounded with an extremely light body of resin which is a nonmagnetic body and the magnet is exposed in the surface only where it contacts the piping; and an extremely small step is formed between the terminal surface of the probe 1 and the surface of the magnet 8. When the probe 1 is brought into contact with the piping 7 to be measured, the grip 9 of the probe 3 is operated at an unreachable narrow place to bring the magnet into contact with a necessary measurement place easily, and the probe 1 oscillates, so the contacting direction is made independent of the direction of the grip 9. The contacting surface is attracted to the contacting terminal of the probe 1 by the magnetic force and the magnetic force intensity of the magnet is adjusted to make the contacting force constant.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention applies ultrasonic waves to the outer surface of the pipes and heat exchangers of a power generation plant by multiplying the wall thickness of the pipes and the wall thickness of the body to generate ultrasonic pulses. When measuring wall thickness with a probe that measures by reflection, when it comes into contact with the outer surface of the object to be measured, if the probe consonant is not applied perpendicular to the thickness direction, an error will occur due to the ultrasonic pulse reflection. To provide a probe r suitable for reducing foot measurement error r by easily applying the probe perpendicularly to the surface of an object.

[Prior art]

In the circular piping of a nuclear power plant, a corrosion phenomenon occurs on the inner surface of carbon steel piping due to factors such as temperature, humidity, and flow properties of the fluid, and the wall thickness decreases due to circular bending. . In some cases, pinholes or cracks penetrating in the inspection direction may develop, and the fluid in the circular part may even leak out. Therefore, ultrasonic waves are transmitted from the outside surface of the piping to confirm the health of the pipe during periodic plant inspections. We used a wall thickness measuring instrument to measure the wall thickness of the roof, and based on the data obtained, we evaluated its wall thinning and lifespan (service life).

The pure water used in nuclear reactors has a neutral pH compared to the water quality in boilers at other thermal power plants, so it is difficult to form an oxide film on the inner surface of the pipes, which is why this thinning phenomenon occurs relatively. It is being said. The present invention utilizes the ultrasonic measurement method used to measure wall thickness, which measures wall thickness by directly contacting the object and reflecting ultrasonic pulses. This relates to the structure of the probe used for measurement. With conventional probes, the measurer manually presses the probe against the outside surface of the pipe so that the contact surface of the probe is perpendicular to the outside surface of the pipe to measure wall thickness. Where is the ground plane of the child evenly distributed on the pipe surface? Is it a digital numeral that is displayed after you look at it? reading. A probe at this time?
The pressing pressure may vary depending on the angle of the workbench, or depending on how hard you hold the probe in your hand, it may result in a one-sided push, resulting in irregularities in the measurement data. After placing the child in an object, I let the child move slightly around the object, and when I felt that there was no movement, I collected the data. A commonly used probe is 10.0 mm in diameter x 10.0 mm in width. The story of the book of legitimacy before and after Om - f: The structure that generates ultrasonic sound inside and the one pulse that transmits to the object is inside t.
i, it has been done. Therefore, it is sized so that a worker can easily hold it with one hand, and has a connecting cable of about 1 NL between it and the digital clothing equipment.

Generally, the piping inside the factory is run close to the ceiling or wall, so the measuring feet are assembled and work is carried out nearby, but depending on the location, the person making the measurements has finally arrived. There are many places where measurements are taken in narrow spaces such as small spaces, or places where the entire circumference of the pipe is not flush with the front.゛In some cases, especially at nuclear power plants, it may be necessary to measure pipes where radiation levels are very close to each other. In this way, when measuring the wall thickness of a pipe under various salinity conditions, the uniformity of the pressure of the probe and the state of uneven contact may vary depending on the posture and position of the measuring worker at the time, as mentioned above. A measurement error of approximately 1 degree must be expected in the resulting data.

The measured alignment α and the surface of the body of the heat exchanger are measured using the probe t.
Before application, remove moisturizer and remove any adhesion of clothing with a rag or the like to make sure there are no inclusions between the contact surface of the probe and V). In the case of piping, the measurement depends on the type of data required, but the measurement is at the intersection point of the 50-pin grid! J
Is the thinning situation determined or partially detailed? In this grid to know? It can also be measured by dividing it into small pieces and using a LOnan pinch.

The ground terminal of the probe has a diameter of about 10 mTn per page.

[Purpose of the invention]

As mentioned above, the probes that have been popular in the past are pressed against each other by the feeling of the measuring worker's hands, so there are subtle differences in the strength of the pressing force and the uniformity of the heat υ on the terminal surface. A difference will arise. In places where you can barely reach the target, you may not be able to rely on the sensation of your hands.
The aim is to improve the probe in order to reduce the amount of damage as much as possible.

[Summary of the invention]

The outline of the present invention is that in an ultrasonic probe for wall thickness measurement, the transmitter itself has the same configuration and structure as the conventional one, but an outer ring surrounds the probe ring around the outer periphery of the probe. Inside the outer ring, a magnet is placed uniformly around the entire circumference to generate lines of magnetic force against the ground surface of the probe, that is, the measuring proboscis of the memo. Also, the probe 'L with this magnetic force is connected
This is because the connection port of the cable has a structure that allows angle rotation, allowing the worker to ground the object without handling it with his/her hands.

If the magnet is used to absorb and leak from an object, the VrC terminal surface will be pressed against the surface. Although stainless steel pipes are also used for plant piping, the majority of pipes are carbon steel pipes, which are magnetic. Rust-free steel pipes have no problems with corrosion or thinning.

[LOL M example of invention]

An embodiment of the invention? Shown in Figure 2. The probe 1 is an ultrasonic probe body, which has exactly the same configuration and structure as a conventional probe. Is the external body 12 the subject of the present invention? It is what you do.

As shown in the figure, this outer ring body 12 is designed to surround the outer circumference of the probe l, and the inside thereof is '/? - (d (6 stones 8 are built in. This magnet 8 can be either a permanent magnet or a magnet, but when it is horizontally installed or grounded on the outer surface of a vertical pipe, it is magnetically attracted to the carbon steel structure. The outside of the magnet 8 is surrounded by an extremely lightweight material such as non-magnetic resin, wood, or aluminum so that the magnet is exposed to the surface only when it is grounded to an object. The terminal surface of the probe and the surface of the magnet are designed to create a minute difference in level.This is because if the outer surface of the object to be measured is curved (elbow, cheese, etc.) or has a curved surface, This is to prevent it from interfering with the grounding of the terminal surface.Outer ring body 12
Is the divided ii a magnet? If the magnet 8 is assembled in a sandwiched structure, it will be easy to replace or adjust the magnet 8 by adjusting the strength of the magnetic force or the level difference between the outer surface and the magnet surface. Measured object piping 71 (
Ni's probe? When grounding, in a narrow place where the operator cannot reach, the probe can be placed at the desired measurement point by using the handle 9). Since the grounding is easy and the probe can swing, the direction of grounding is also in the direction of the handle 9.
1. It can be operated without any trouble. The ground terminal of the probe is uniformly attracted to the surrounding area by the magnetic force, and the ground pressure can be made constant by increasing the magnetic force strength of the magnet. If the magnet 8 is a grinding magnet, it will be easier to move the probe from a remote location.

Outer ring body 12? As a method of defeating the probe 3, a screw-in method sound is used. Screws on the contact circumferential surfaces of the tabs and the outer ring 12 and the probe 3? In order to make it possible to cut and slide it off, there are some considerations such as the strength of the magnetic force of the magnet 8 that is attached surrounded by the outer ring 12, and the difference in level between the terminal surface and the magnet surface. It becomes easy to replace and adjust the magnet 8.

The magnet 8 is surrounded by an outer ring 12 made of a non-magnetic material, and by leaving the field magnet on the side in contact with the object to be measured exposed to the surface, iron powder etc. in the surrounding dust can be removed. This solves problems such as sticking to magnets and causing errors in accurate measurements.

The terminal surface of probe 1 and the surface of the magnet are designed to have a minute difference in level, but in addition to the above-mentioned effect (l), this also creates a rough surface on the outer edge of the object to be measured. If there are scratches,
If there is no step difference between the terminal surface and the magnet surface, the terminal surface will be at about 1 level with respect to the measurement surface, resulting in problems such as not being able to receive reflected pulses or not being able to collect accurate numbers. However, by creating a step between the terminal surface and the magnet surface, this problem can be solved. It can be solved.

An example of wall thickness measurement work performed by remote control using the handle '/c is shown in FIG. The probe 3 and the handle 9 can be rotated in only one direction via the arm 10 and the bottle 11.
By inserting the handle 9 into the arm 10, the handle 9 can be replaced.What is the length of the handle 9? Since it can be freely adjusted 7, it becomes possible to perform remote control via the handle 9 to measure the wall thickness of piping located in narrow spaces near walls or at high places.

By adding seven flexible materials to the cable 5, it is possible to follow the rotation of the arm 1o.

In addition, in remote measurement using the handle 9r, it is necessary to use a force exceeding the magnetic force to disintegrate the probe after measurement, or it is necessary to use a magnet 8 to remove the probe. The tentacles can be moved more easily.

[Efficacy of invention. Fruit]

The effect of the present invention is that vertical and uniform grounding suitable for the purpose of measuring the wall thickness of the object to be measured can be reliably established by inserting the main stone r into the outer outer part of the probe.

Also, due to the attractiveness of this magnet, it may cause damage to workers' hands. Thickness measurement must be possible even if the probe is detached from the probe.

Therefore, it is difficult for workers to directly access piping located near walls, in narrow spaces where workers can barely reach their hands, or where radioactivity is high. ! I! Is this probe VC handle suitable for measurement work in areas that you don't want or are difficult to access? It is also possible to measure wall thickness in areas that are difficult to reach by hanging the device.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional ultrasonic wall thickness measuring probe, FIG. 2 is a cross-sectional view of a probe according to the present invention, FIG. 3 is a bottom view of a probe according to the present invention, and FIG. FIG. 4 is an explanatory diagram of an example of remotely operated pitch thickness measurement in a narrow space according to the present invention. 1... Probe, 2... Vibrator, 3... Probe, 4
... Receiving and sending 1g body, 5... Cable, 6... Cover, 7... Assisted object] Fixed object, 8... Magnet, 9... Handle, lo... Arm, ii...・Bin, 12...Outer ring, 13...Digital display device, 1st area bZ area 1st entrance

Claims (1)

[Claims] 1. An ultrasonic wall thickness measuring probe used for measuring the wall thickness of piping, which is surrounded by a cylindrical magnet and has a structure. A sonic wall thickness measurement probe. 2. An ultrasonic wall thickness measurement probe as claimed in claim 1, wherein the probe supporting the probe has a structure in which a handle capable of rotation i=J is provided.