检定超声波探伤仪用的脉冲信号延时器

检定超声波探伤仪用的脉冲信号延时器王军义（中国河西化工机械公司计量站，呼和浩特０１００７６）根据ＪＪＧ（航天）５３─８８《Ａ型脉冲反射式超声波探伤仪》计量检定规程，在检定Ａ型脉冲反射式超声波探伤仪（以下简称探伤仪）时，需要一台辅助仪器“脉冲信号延时器...     

超声波探头回波频率测试方法

0引言超声波探伤仪主要用于检验锻件、铸件、厚钢板、薄板、线材、管材、焊缝、条棒等金属材料的内部缺陷和有关金属材料件的厚度测定。超声波探头一般由压电晶片、外壳、电缆线和接头等部分组成。探头作为超声波振动和电振荡之间的电声转换器,是相当于超声波探伤仪的感觉器官的重要部分。超声波探伤中,     

超声波检测焊缝缺陷深度的不确定度评定

采用GUM法对超声波检测焊缝缺陷深度的测量不确定度来源进行了分析,并对检测过程中的测量不确定度进行了评定。结果表明:超声波检测焊缝缺陷深度的不确定度来源主要有超声波探伤仪水平线性误差、斜探头性能以及试块规格;为了得到精确的测量结果,测试前应对超声波探伤仪水平线性误差进行检查并确保其在合适范围内,然后选用合适的探头及试块。     

超声波探伤仪检修的几点体会

超声波探伤是造船工业必不可少的工序,船体焊接质量关系到整个船只的质量.我厂每年都要承接许多船舶的建造任务,工作现场的恶劣环境和意想不到的情况都可能对使用中的超声波探伤仪造成伤害和损坏。为了能保证高速高质量完成建船任务，我们必须及时将那些损坏的探伤仪修好。这是一项量大且繁琐的工作。通过近几年对上百台探伤仪的检定与修理，笔者摸索出一些维修经验。     

超声波探伤仪检定方法探讨

本文以实例分析了超声波探伤仪衰减器衰减量误差检定存在的问题，并提出了合理的判定方法。本文还介绍了超声波探伤仪最大使用灵敏度的一种实用检定方法。     

超声波探伤仪的检定

本文主要谈超声波探伤仪为什么要进行周期检定，并结合工作实际介绍其检定方法，程序和经验。     

虚拟超声波探伤仪USB2.0高速数据传输平台设计

为满足虚拟超声波探伤仪高速数据传输要求,设计一种基于虚拟技术的USB2.0高速数据传输平台,实现了最高可达16MByte/s的数据传输速率。探伤系统采用上下位机的形式,上位机采用兼容PC平台,Windows XP操作系统,选择Cypress公司提供的WDM通用驱动程序,并通过其编程接口获取探伤数据,应用层软件采用VC6.0开发;下位机采用TI公司TMS320C6000系列DSP,负责数据采集、传输。由于USB 2.0高速接口的传输速度可达到480Mbit/s,能够满足虚拟超声波探伤系统对高速数据传输的要求,而且采用USB2.0接口使得虚拟探伤子系统成为一个与PC相对独立的整体,使用方便,有助于减小外界的干扰。且USB2.0接口即插即用,也方便在笔记本电脑上使用。所完成的系统结构简洁、性能优异,可满足虚拟超声波探伤仪的实际需求。     

旋转磁场探伤仪检测方法的研究

为加强对无损检测仪器的监督和管理,国家陆续出台了《X-ray探伤仪》检定规程、《超声波探伤仪》检定规程,但是现有计量检定规程中还没有关于     

ZJ-2超声探伤仪检定装置垂直线性不确定度评定

本文主要对ZJ-2超声波探伤仪检定装置垂直线性不确定度的评定分析。     

超声波探伤仪的现场应用

<正>一、超声波探伤可靠性的实现超声波探伤仪的可靠性和稳定性非常重要。开展超声波探伤仪的检定工作时,依据JJG746-2004《超声探伤仪检定规程》,对超声波探伤仪的主要性能:垂直线性、水平线性、衰减误差、动态范围以及最大使用灵敏度等进行检定。另外对比试块材料与受检件的成分,组织声学特性应一致或相似。对比试块材料的内部纯净度利用入射角为0°的直射超声波,在规定的工作频率和灵敏度下进行扫查,不得有大于或等于比受     

Remote diagnostics of soft solids using nonlinear acoustic methods

A prototype of a new flaw detector for remote noncontact diagnostics of soft solids is proposed. The operating principle of the flaw detector is based on the features of the nonlinear interaction of two ultrasonic waves in the test material with defects. Ultrasonic waves in the test material are excited remotely by ultrasonic beams focused in air. It is demonstrated experimentally that with the help of the proposed flaw detector, subsurface defects with dimensions much smaller than the wavelength of the probing ultrasound can be remotely detected and localized.     

CTS-26型超声探伤仪典型故障的分析与排除

在简要介绍CTS-26型超声探伤仪工作原理及组成的基础上。对其几种典型故障作了具体的分析和处理。     

Time of flight diffraction imaging for double-probe technique

Due to rapid progress in microelectronics and computer technologies, the system evolving from analog to digital, and a programmable and flexible synthetic aperture focusing technique (SAFT) for the single-probe pulse-echo imaging technique of ultrasonic nondestructive testing (NDT) becomes feasible. The double-probe reflection technique usually is used to detect the nonhorizontal flaws in the ultrasonic NDT. Because there is an offset between the transmitter and receiver, the position and size of the flaw cannot be directly read from the image. Therefore, a digital signal processing (DSP) imaging method is proposed to process the ultrasonic image obtained by double-probe reflection technique. In the imaging, the signal is redistributed on an ellipsoid with the transmitter and receiver positions as focuses, and the traveltime sum for the echo from the ellipsoid to the focuses as the traveltime of signal. After redistributing all the signals, the useful signals can be constructively added in some point in which the reflected point is; otherwise, the signals will be destructively added. Therefore, the image resolution of the flaw can be improved and the position and size of the flaw can be estimated directly from the processed image. Based on the experimental results, the steep flaw (45°) cannot be detected by the pulse echo technique but can be detected by the double-probe method, and the double-probe B-scan image of 30° tilted crack is clearer than the pulse echo B-scan image     

Frequency-Wavenumber Migration of Ultrasonic Data

In ultrasonic nondestructive evaluation (NDE), the depth of the image is usually calculated by multiplying the traveling time of the echoes with the velocity of the medium. If the flaw is not a horizontal plane, the flaw images may be distorted and mislocated. Although the lateral resolution and sizing accuracy of the flaw image can be improved using the digital signal processing methods, e.g., the utilization of the blocking filter or deconvolution filter, these methods do a little favor about the distortion and mislocation problems. The migration, an image-processing method used widely in reflection seismology, is introduced to process the ultrasonic data in this study. Since the signals are coherent and the noises are random, the flaw image can be transformed from its apparent position to the true position using the migration method and the resolution of the image may be improved. Not only the real positions of the oblique cracks can be found upon applying the frequency-wavenumber (F-K) migration to process ultrasonic data, but, in addition, the dimensions of the flaws can be estimated more accurately. Results presented in this study show that the migration method can be applied successfully to the ultrasonic data processing and can improve the quality of ultrasonic image in both size and location of the flaws.     

磁轭式磁粉探伤机提升力测量装置的研制

磁粉探伤是一种重要的无损检测方法,在生产实际中得到了广泛应用。磁粉探伤机的性能指标稳定并满足工作要求,是保证其检测结果准确可靠的前提,磁粉探伤机最关键的性能指标就是其磁轭的磁化能力,目前国内常用的磁化能力校验方法是提升力测试法。本文根据磁轭式磁粉探伤机提升力的定义,利用智能传感器和高速数据采集技术,研制出了一种磁粉探伤机提升力测量装置,本装置操作简便,结果直观,不用再使用笨重的提升力测量试块,大大提高了校验效率,取得了良好的社会效益和经济效益。     

Porous Piezoelectric Ceramics: Materials for Ultrasonic Flaw Detection and Medical Diagnostics

The key features of the piezoelectric materials for ultrasonic transducers are considered. A procedure is described for the fabrication of porous piezoelectric ceramics. It is shown that, owing to their high piezoelectric performance and ease of fabrication, porous ceramics may compete with lead niobate and piezoelectric composites in the fields of medical diagnostics and ultrasonic flaw detection.     

An ultrasonic time-of-flight equivalent flaw sizing method

One of the challenging tasks in the field of ultrasonic NDE is to obtain quantitative flaw size, shape, and orientation information. In an equivalent flaw sizing approach, flaws in a material are reconstructed in terms of a best-fit simple shape such as an ellipsoid or ellipse. In this work, a new time-of-flight equivalent (TOFE) flaw sizing method is developed for obtaining best-fit equivalent flaws from a relatively small number of timing measurements at different transducer orientations. The performance of the method is demonstrated on synthetic numerical data and with experiments, including examples of sizing in anisotropic composite materials and in welds.     

A unified constrained inversion model for ultrasonic flaw sizing

Equivalent flaw sizing using ultrasonic waves is an approach whereby shape and orientation information of a defect are obtained in terms of a best-fit simple geometry that is able to represent the major aspects of the flaw. Separate examples of this approach have previously been developed for volumetric flaws and cracks using the Born and Kirchhoff approximations, respectively. Here, these separate algorithms are unified into a single algorithm capable of sizing both volumetric flaws and cracks. Some examples of the performance of this unified algorithm on both synthetic and experimental data are also given.     

The role of flaw size and fiber distribution on tensile ductility of PVA-ECC

Polyvinyl Alcohol-Engineered Cementitious Composites (PVA-ECC) designed based on micromechanics exhibit high tensile ductility (above 1%) and limited crack widths (below 100 μm). The tensile performance of ECC is dependent on the fiber and flaw size distributions. These parameters are known to be influenced by the matrix flowability and mix processing; however, a comprehensive quantitative analysis framework linking fiber and flaw size distributions to the tensile performance of PVA-ECC is needed to supplement theoretical understanding of the relationship between micromechanical parameters and composite macro-properties. In the present work, fiber distribution (dispersion and orientation) of two different ECCs in terms of matrix flowability was investigated using fluorescence microscopy and advanced digital image analysis. The maximum flaw size distribution along the specimens was also analyzed by cross-sectional image analysis. The influences of fiber and flaw size distributions on the composite behavior of PVA-ECCs were experimentally established.     

Y型过滤器超声探伤研究

Y型过滤器焊缝布置复杂,探伤实现困难。本文利用HS600数字式超声波探伤仪分别实现了各焊缝的超声波检测,方法简单可行。