您现在的位置:上海澜睿机电科技有限公司 > 技术论文> 涡流检测ET

Another inconvenience that arises during the eddy current testing of heat exchanger tubes is that although phase analysis(measuring defect depth based on the angle on the screen)is usually the best measure of a defect’s depth,it is not perfect.


The two eddy current screens shown in the diagram are a bit cluttered because you can see the dent and five defects of an ASME calibration tube that we’ve used for examples in previous articles.The green horizontal signal is,of course,the dent signal.Then,rotated clockwise from this at about 45 degrees,are the through wall hole,followed by the 80,60,40,and 20 percent O.D.pits,all of similar amplitude.Then,superimposed on these is an additional defect larger in amplitude.Just what might this be?


In the ect MAD 8D Eddy Current Software,a new feature has been turned on.This is the ect AutoMAD Analysis Mode,in which the software measures the defect depth of all the defects it encounters in a tube,and then displays a list of up to the 10 deepest defects.This list appears where the Mixer Menu used to be;therefore,appears under the word“Mixer”.The deepest defect encountered is listed as 99 per cent on the I.D.This is,of course,the through hole.(The one per cent error is actually excellent and not to be expected in the field environment.This example was created in a carefully controlled laboratory environment.)Listed below this through wall hole you can pick out the other five outside defects;specifically,the 80,60,40,and 20 per cent O.D.defects,all ranging in amplitude from 1.0 volts to 1.8 volts.(Note that below the 20 per cent O.D.defect is listed a nine per cent I.D.defect.This is,in fact,a 10 per cent I.D.groove,which is not shown on the screen.)

在ECT MAD80D软件里,增设了一个新的功能特点.图中为ECT AutoMAD分析模式,该模式下,软件可以测量所有碰到的缺陷的深度,然后可以显示10个最深缺陷的清单。当Mixer Menu在启用状态下时,便显示在单词Mixer下面。最深的缺陷以99%显示,当然实际上它已经是通孔缺陷(1%的误差实际上已经非常好了,在现场检测时很难达到这个结果的,本案例是在精心控制的实验室环境下得到的)。在清单中接下来便是5个缺陷显示,尤其是80%,60%,40%,20%的缺陷,幅度均在1.0到1.8V之间。


Now back to this new,larger defect that appears on the screen,which is marked by the cursors.(Square at the top and a cross at the bottom.)The signal is larger in amplitude;therefore,it is logical to assume that the defect is of greater volume.The angle of this defect is rotated counter clockwise from the 20 per cent O.D.pit;therefore,it would be logical to assume that this is an O.D.pit deeper than the 20 per cent in the calibration tube,but shallower than the 40 per cent,but larger in diameter in order to make up a larger volume.In fact,the data analysis shows this defect as being 36 per cent through the wall on the outside with a magnitude of 2.9 volts.Unfortunately,this is not what the defect is.


This signal actually originates from a concentric O.D.groove 3 mm long but only 10 per cent through the wall from the outside!


Apparently and unfortunately if a defect were to grow larger in volume while retaining the same defect depth,its resulting eddy current signal would rotate counterclockwise and the signal would grow in amplitude.In this case,by directly applying phase analysis using a calibration table based on the ASME O.D.pits,this 10 per cent O.D.defect is incorrectly measured as 36 per cent O.D.


The same is true if the defect was a 100 per cent through wall hole.If you drill holes of different diameters in a calibration tube and measure the eddy current response,you will notice that the larger the diameter of the hole,the more the hole rotates counter clockwise.


This problem becomes even worse for defects on the inside of the tube wall.One reason that this problem is greater on the inside(assuming that these tubes are being inspected from the inside)is that the most important part of the defect is the part in the deepest part of the flaw.This part is farthest from the probe;therefore,the probe has the least sensitivity to it.The eddy current signal is more due to the shallower portion of the defect closer to the probe.The result is that very large diameter pits on the I.D.can easily be interpreted as being much less deep than they actually are.


So,what can be done about it?The most common advice you will hear in eddy current testing is to make the defects in your calibration tube as close to the size and shape of the defects you are trying to measure as possible.As a result,you may need more than one calibration table to correlate phase to defect depth if you have more than one defect type in a tube.Actually,the ect MAD 8D Software has multiple tables,which can be selected by the user depending upon the type of damage that is being measured.

那么,有什么可以做得呢?通常的建议是做一个尺寸和形状跟预期结果都相近的试块。结果是,你可能需要更多的校准表格来关联缺陷深度,你还得建立一个以上的管材的缺陷类型。这里,我们ECT MAD 8D软件内置了多个表格,在检测过程中,你可以根据预期检测的缺陷类型来选择相应的表格。

An example of how this may occur could be a water cooled condenser.This type of tube may have multiple,small diameter pits caused by corrosion,but the occasional very large diameter pit caused by erosion where an object had been stuck in the tube.Based on noting the amplitude difference,the Inspector analyzes with the appropriate calibration table and accurately measures the defect depth.


ECT 48 Specifications参数

ECT 48 Main Features特点

Differential, Absolute, and Send/Receive
with industry standard 4-Pin MS Connector

The ect 48 Eddy Current System, designed for inspecting ferro and non-ferromagnetic heat exchanger tubes,has up to four simultaneous injection frequency channels and two mixers.
ECT 48个涡流系统,用于检测铁和non-ferromagnetic热交换器管,有四个同时注入频率通道和两个搅拌机。


  • Simultaneous Injection (SI)
  • Simultaneous Sampling (SS)
  • Up to 12,000 Hz sample rate, each channel, allows up to 10 feet per second probe speed at over 100 samples/inch.
  • 12000 Hz采样率,每个通道,允许10英尺每秒探测速度超过100样本/英寸。
  • Automatic data analysis.
  • 自动数据分析
  • Save and recall unlimited test setups.
  • 测试结果无限制保留和重复使用
  • Defect signals are highlighted in real time during recording or playback.
  • 记录和回放时,缺陷信号实时突出标示
  • Four independently selected simultaneous frequencies.
  • 4个独立选择的同步频率
  • Digital Signal Processing (DSP) HP & LP filtering provides lower noise.
  • 数字信号处理(高通和低通过滤提供低噪音水平)
  • Independent horizontal and vertical display scaling.
  • Signal phase and amplitude measurement functions.
  • 独立的水平和垂直显示, 信号相位,幅值测量功能
  • Defect depth measurement functions.
  • 缺陷深度测量功能
  • Standard printer interface.
  • 标准打印接口
  • Single keystroke data acquisition.
  • 单键数据获取
  • Single keystroke data playback with analysis.
  • 单键数据回放和分析
  • Optional ect 48 Data Analysis Software.
  • 可选ECT48 数据分析软件
  • Optional ect Frequency Transforms* use eddy current signals in the frequency domain, making it easy to distinguish between magnetic inclusions, roll stops, and serious defects.
  • 可选频率转换器,用涡流信号在频率范围内,使其容易区分磁性夹杂,滚轮停印和严重的缺陷
  • Optional ect Data Storage Software stores and recalls eddy current signals on disk.
  • Optional ect Report Software reads the defect listprovided by
    the ect 48 Data Analysis Software and provides tube sheet maps
    color-coded based on defect depth.
  • 16 16-Bit Analog-to-Digital Conversion so all channels are sampled in
    the same microsecond.

ECT 48 Accessories附件

  • Power Cord
  • Manual


  • Carbon Steel Filter Amplifier for simultaneous Remote Field and
    Near FieldTM inspecting of ferrous tubes
  • ect 48 Data Analysis Software
  • ect 48 Frequency Transform Software*
  • ect Report Software
  • Built-in DVD writer
  • Transit Case
  • Separate Data Analysis System
  • Available in Micro Dock configuration
  • 1。碳钢过滤器同时远程领域和放大器附近FieldTM亚铁管的检查
    2。ECT 48数据分析软件
    3 ECT 48 *频率转换软件
    4 ECT48 报告软件

ect 48 Ordering Information
The ect 48 Micro Dock Eddy Current System has many more features than can be described on this brochure.
ECT 48微涡流系统有许多更多的功能比可以描述在这个手册。


RANGE范围:40 Hz to 5 MHz Stability稳定性 + 100 PPM

TRANSFER CHARACTERISTICS转换特性, 4 Frequencies, One Probe4个频率,一个探头

SENSITIVITY灵敏度:135 Volts/Ohm min. at 30 kHz at max. gain setting

GAIN增益:90 db at maximum gain setting最大增益条件下90分贝

DRIFT飘移:Less than 0.1 Volts per hour at 60db gain with probe

NOISE噪音: Less than 30 mV P-P at nominal gain正常增益条件下小于30mV

LP Filter: 5 to 1,000 Hz

HP DSP FILTER: 0.1 to 14 Hz

LP DSP FILTER: 12 to 1,440 Hz

BALANCE平衡: High speed successive approx. electronic balance高速连续电子平衡

MULTIPLEX MODE多通道模式: 32 Channels

STORAGE DISPLAY MODES WITH 1280 x 1024 SCREEN 储存显示模式带1280x1024显示屏

12 XY Impedance Planes and 2 Strip Charts
12个XY独立平面和两个Strip Charts


GAIN增益: 999 Linear Steps线性

PHASE相位: 360 Degrees

FREQUENCY频率: 20 Hz – 5 MHz in 1 Hz Steps

VOLTS/DIVISION电压: Separate Horiz. & Vert.水平和垂直 .06, .13, .25, .5, 1, 2, 4, 8, 16 V/Div

BALANCE平衡: Each channel independent or all simultaneously每个通道独立或者所有通道同时

POSITION定位: + Full Screen, Horizontal and Vertical全屏,水平和垂直


INPUT PHASE输入相位: 360 Degrees

OUTPUT PHASE输出相位: 360 Degrees

HORIZ. WEIGHT水平重量: 0 – 999%

VERT. WEIGHT垂直重量: 0 – 999%

VOLTS/DIVISION电压: Separate Horiz. & Vert水平和垂直. .06, .13, .25, .5, 1, 2, 4, 8, 16 V/Div

POSITION定位: + Full Screen, Horizontal and Vertical全屏,水平和竖直

CANCEL取消: Automatic自动


SAMPLE RATE取样速率: 100 Hz to 12 kHz, All Channels Simultaneously


Meets or exceeds ASME Section V & XI requirements


VOLTAGE电压: 90-130 and 185-270 Vac auto selected

FREQUENCY频率: 50-60 Hz

POWER功率: 100 Watt Max

关于我们 新闻动态 荣誉证书 人才招聘

上海澜睿机电科技有限公司 版权所有 严禁复制 2016
网站备案号:沪ICP备16033523 上海网络营销|营销型网站上频