32results about How to "Large measuring depth" patented technology

The invention discloses a welding seam measuring method based on micro field depth, comprising the following steps: placing a camera with optical amplification factor being more than 2 slantwise relative to the local surface of a welding seam, shooting the local surface of the welding seam twice under the condition of different distance between camera and the local surface of the welding seam, extracting clear bands from two shot images, respectively obtaining the coordinate of each object point which corresponds to each image point on the centre lines of two clear bands in a direction perpendicular to the welding seam to obtain two straight line segments in a world coordinate, carrying out plane fitting by using the two straight line segments to obtain the normal vector value of the local surface of the welding seam, and extracting the boundary of the local surface of the welding seam from any one of the clear bands to obtain the width and the center coordinate of the local surface of the welding seam. The welding seam measuring method can be used to stably and reliably measure the center coordinate, the width and the normal vector value of the local surface of the complex micro-fine welding seam, is easy to operate and has high detection precision.

The invention discloses a device and a method for measuring soil body displacement in a layering mode. The device for measuring soil body displacement in a layering mode comprises a casing pipe, a pre-buried rod piece and a displacement meter. The casing pipe is buried in a measured soil body, the pre-buried rod piece is movably arranged in the casing pipe in a penetrating mode, the pre-buried rod piece comprises an extension bar, the top of the extension bar is connected with a carrier rod, the bottom of the extension bar is connected with a base, a groove is formed in the top of the carrier rod, the bottom of the base stretches out from the bottom of the casing pipe to form a chassis, the chassis is arranged on a measured point, the displacement meter is fixed over the carrier rod, a centre of the displacement meter abuts against the interior of the groove, and the center symmetric line of the displacement meter and the center symmetric line of the pre-buried rod piece are located in a same straight line. The pre-buried rod piece and the casing pipe are buried in the measured soil body in advance, then the pre-buried rod piece can generate relative displacement in the casing pipe, layering displacement of stratums is conducted to the ground, and therefore displacement of the soil body with designated depth can be measured. The device for measuring soil body displacement in a layering mode is simple and reliable in structure, can be reused, and is particularly suitable for measuring displacement of the deep soil body in a test.

The invention relates to a signal transmission and measurement device for directional wells in oil drilling, which is a composite electromagnetic wave transmission and measurement device while drilling, which includes a signal relay transmitting device, a lower instrument measuring device and cables; The cross rotating short joint, the upper end of the cross rotating short joint is fixedly equipped with a launching cable head, and a launching centralizer is fixedly installed on the signal relay transmitting device. The present invention has a reasonable and compact structure, and is easy to use. The cross rotating sub-joint and the rotating sub-joint can prevent the cable of the present invention from being twisted during use. At the same time, the present invention can effectively overcome the problem of limited transmission distance of electromagnetic wave signals in the bottom layer and increase the frequency of electromagnetic waves. The measurement depth of the instrument, and the large amount of data transmitted by the cable transmission signal, the transmission speed is fast, will not affect the measurement efficiency, and in the process of signal transmission, the twisting of the cable can be effectively avoided.

The invention provides a method for carrying out ultrasonic inspection on residual stress of an aluminium alloy pre-stretching board by water immersion, belonging to the field of non-destructive inspection. The method comprises the following steps of preparing a reference block; carrying out measurement and calibration; measuring the residual stress. In the method, the water immersion method is adopted, and the temperatures in stress calibration and stress measurement processes can be ensured to be consistent by controlling the water temperature not to be changed, thus eliminating the effects of temperature difference on the ultrasonic wave speed and eliminating temperature errors; besides, an automatic scanning frame is adopted instead of manual scanning, so that the distance between a probe and the surface of a material to be measured in the measurement process can be ensured not to be changed, thus eliminating the effects of coupling condition difference on sound propagation time and eliminating the coupling errors. The method is beneficial to non-destructive evaluation of the near surface residual stress of the aluminium alloy pre-stretching board.

The invention discloses a modulation profile measurement system and method based on oblique focusing and rotational scanning. By placing the grating obliquely on the optical axis, the clear image plane becomes an oblique plane in the measurement space, and a high reflective mirror is placed behind the projection lens. The optical axis is deflected by nearly 90°, and the rotating mirror makes the fringe clear. The imaging surface completes the scanning of the entire surface of the measured object. The CCD camera captures the fringe pattern carrying the surface information of the object synchronously through the beam splitter. Using phase shift technology, the fringe The modulation degree curve of each pixel is obtained from the light intensity information, and the height of each pixel can be reconstructed by using the known system mapping parameters according to the obtained modulation degree peak number. The invention adopts rotary scanning instead of axial scanning, so that the measuring system is more flexible and compact, and the oblique placement of the grating can also significantly expand the measuring depth.