完善资料让更多小伙伴认识你,还能领取20积分哦, 立即完善>
你好。
我拥有一台DSO-X 2002A 2通道70MHz 2 GSa / s示波器,我正试图通过发射器/接收器P波换能器在岩石核心内的某些边界的反射上进行双向传播。 问题是我只看到示波器显示屏上的脉冲。 我检查了电缆是否连接在正确的端口,经过了所有可能的配置(Itried改变波的频率,幅度,增益,阻尼,高通和低通滤波器等等,它仍然没有给我 一个值得分析的信号)。 我的岩石核心长度为6.5厘米,p波速度略高于4000米/秒,其中第一个也是最重要的边界是在第一个1厘米之后,尽管应该给出最高阻抗的边界是边界 它的核心和铝板下面(6.5厘米),我在信号中看不到。 prtscr.jpg是脉冲发生器的规格; sig_inter.png是没有核心连接到传感器的信号; dig_read_inter.png是核心连接到传感器的信号。 任何人都可以帮我弄清楚为什么我无法看到边界反射的正确信号? 干杯! sig_inter.png22.0 KBprtscr.jpg112.6 KB 以上来自于谷歌翻译 以下为原文 Hello. I possess a DSO-X 2002A 2 channel 70MHz 2 GSa/s oscilloscope and I'm trying to two way travel time's on reflections in some boundaries within a core of rock through a transmitter/receiver P-wave transducer. The problem is that I only see the impulse on the oscilloscope's display. I've checked the cables are connected in the right port's, went through all of the configurations possible (Itried to change the wave's frequency, amplitude, gain, damping, high and low pass filters and so on and it still isn't giving me a signal worth analyzing). My core of rock has 6,5cm lenght, p-wave velocity is a tiny bit higher than 4000m/s and the first and most importante boundary within it is just after the first 1cm although the boundary that should give the highest impedance is the boundary of the core and the aluminum plate it has underneath (at 6,5cm) which I don't see either in the signal. prtscr.jpg is the specs for the pulser; sig_inter.png is the signal without the core attached to the transducer; dig_read_inter.png is the signal with the core attached to the transducer. Can anyone help me figure out why I haven't been able to see a proper signal with the boundaries reflections? Cheers! 附件
|
|
相关推荐
8个回答
|
|
听起来你正在做的是TDR或TDT测量。
在4000米/秒时,1厘米将约为2.5微秒。 1厘米反射的往返时间约为5usec。 6.5厘米反射的往返行程约为32次。 你有一个30+ usec的标记,所以这可能是远反射。 5 usec的大型游览可能是近距离的。 这是所有猜测,因为我不知道我在两张图片中看到的是什么。 这实际上不是示波器问题。 您需要与换能器人员交谈,并可能获得已知结果的已知样本进行比较。 像任何TDR / TDT问题一样,有各种各样的回声可以回来,这是将信号(重要反射)与“噪声”(其他一切)分开的问题。 免责声明:为了获得更可靠的响应,您应该考虑致电当地的安捷伦技术呼叫中心。 安捷伦论坛在“可用”的基础上进行监控,并不一定是解决技术问题的最快方式。 以上来自于谷歌翻译 以下为原文 Sounds like what you are doing is a TDR or TDT measurement. At 4000m/s, 1 cm would be about 2.5 usec. Round trip time for a 1 cm reflection would be about 5usec. Round trip for a 6.5 cm reflection would be about 32 usec. You have a marker at 30+ usec, so that may be the far reflection. There's a large excursion at 5 usec that may be the near one. This is all speculation, since I have no clue as to what I'm looking at in either picture. This is really not an oscilloscope problem. You need to talk to the transducer people and maybe get a known sample with known results to compare to. Like any TDR/TDT problem, there are all sorts of echos that can come back, and it's a matter of separating the signal (important reflection) from the 'noise' (everything else). Al Disclaimer: For more reliable response, you should consider calling your local Agilent Technical Call Center. The Agilent Forums are monitored on an "as available" basis, and aren't necessarily the fastest way to get technical questions answered. |
|
|
|
感谢您及时回复algoss。 TDR或TDT是什么意思? 你的数学似乎是正确的,这也是我得到的。 我看到了一些微妙的标记,但它们的强度不足以被识别为反射。 有没有办法放大信号,以便这些标记只使用配置更明显,更清晰? 另外,因为我更感兴趣的反射是在5微秒,这是接近脉冲的方式,可能与脉冲信号错误...有没有办法用这个设备将噪音与信号分开我是 有兴趣? 另一个问题可能是核心短路,这可能使反射接近脉冲信号。 如果我得到更长的核心,可能更容易选择标记,这不正确吗? 在我看来,你没有正确理解我在这里做什么。 让我试着解释一下你能不能更好地了解发生了什么:我将一个5MHz的P波换能器连接到一个长度为6.5厘米,直径为1英寸的圆柱或岩石上。 我试图从岩石圆柱内的一些不连续点(边界)读取回声,这些不连续点与圆柱体的底部和顶部平行(因此我们应该得到一个很好的反射,尽管边界的化学成分和岩石的其余部分 圆柱体非常相似,这意味着阻抗不会像我们想的那么高,因此我们不会像我们希望获得适当的信号响应一样强烈反射)。 你所谈到的30微秒的标记是从岩石圆柱(核心)到下面的铝板的通道(不同的化学成分=不同的速度=高阻抗=良好的反射)。 这就是为什么我们在30微秒时比在5微秒时获得更好的反射,与5微秒反射与脉冲信号“绑定”或“混合”的事实相结合。干杯! 以上来自于谷歌翻译 以下为原文 Thank you for your prompt reply algoss. What do you mean by TDR or TDT? Your maths seem correct, that's what I got as well. And I see some subtle markers but they're not strong enough to be identified as reflections. Is there a way to amplify the signal in order to these markers be more visible and more clear using just the configurations? Also because the reflection that I'm more interested in is at 5microseconds which is way to close to the impulse and can be mistaken with the impulse signal... Is there a way with this equipment to separate the noise from the signal I'm interested in? Another problem may be the core being to short, which can make the reflections to close to the impulse signal. If I get a longer core, it may be easier to pick the markers, isn't this correct? It seems to me that you didn't understand properly what I'm doing here. Let me try to explain do you can have a better understanding of what going on: I'm attaching a 5MHz P-wave transducer to a cylinder or rock with 6,5 cm lenght and 1 inch diameter. I'm trying to read the echos from some discontinuities (boundaries) within the rock cylinder which are parallel to the base and top of the cylinder (so we should get a nice reflection altough the chemical composition of the boundaries and the rest of the rock cylinder are very similar which means that the impedance won't be as high as we would like so we won't have a reflection as strong as we would like to get a proper signal response). The marker at 30microseconds that you talked about is the passage from the rock sylinder (core) to the aluminum plate beneath (different chemical compositions=different velocities=high impedance=good reflection). This is why we get a better reflection at 30microseconds than at 5microseconds, allied with the fact that the 5microseconds reflection is 'binded' or 'mixed' with the impulse signal.. Cheers! |
|
|
|
我猜到你在做什么,我完全正确。 您应该阅读TDR:http://en.wikipedia.org/wiki/Time-domain_reflectometry本文在电子领域中讨论它,但相同的技术适用于机械领域。 创建入射波并且测量设备观察来自该入射波的反射。 您甚至使用相同的术语,即不连续性,阻抗。 您看到的问题与电气领域中出现的问题完全相同。 如果不连续性太靠近发射机,它将与发射的脉冲混淆。 如果传输的脉冲的波长太低,则各种不连续性将在显示器中融合在一起。 圆柱体两侧的粗糙度也会引起反射,这会在测量中显示为噪声。 你应该真的,真的,读取TDR和TDT。 声音显然以4E3米/秒的速度在岩石中传播。 它在空气中以~3E2米/秒的速度行进。 光在太空中以3e8米/秒的速度传播。 电路板上的走线以~1.5e8 m / sec的速度行进。 除了速度之外,它们都是一样的。 在我进行测量的PC板上,迹线的宽度和厚度可以改变。 表面粗糙度很重要。 到底层地平面的距离可以改变。 所有这些都会导致您看到的效果完全相同。 如果您感兴趣的是前5个usec,那么您应该将Time / div更改为1usec / div左右,从而放大重要信号。 其余的是关于测量技术,你应该与其他人进行相同的机械测量。 免责声明:为了获得更可靠的响应,您应该考虑致电当地的安捷伦技术呼叫中心。 安捷伦论坛在“可用”的基础上进行监控,并不一定是解决技术问题的最快方式。 以上来自于谷歌翻译 以下为原文 I guessed at what you were doing, and I was exactly right. You should read up on TDR: http://en.wikipedia.org/wiki/Time-domain_reflectometry This article discusses it in the electrical domain, but the same techniques apply in the mechanical domain. An incident wave is created and the measurement equipment looks at the reflections from that incident wave. You are even using the same terminology, i.e. discontinuities, impedance. The problems that you are seeing are exactly the same as what is seen in the electrical domain. If the discontinuity is too close to the transmitter, it will be confused with the transmitted impulse. If the wavelength of the transmitted impulse is too low, various discontinuities will meld together in the display. The roughness of the sides of the cylinder will also cause reflections, which will appear as noise in your measurements. You should really, REALLY, read up on TDR and TDT. Sound apparently travels at 4E3 m/sec in rock. It travels at ~3E2 m/sec in air. Light travels at 3e8 m/sec in space. Electrical impulses travel at ~1.5e8 m/sec in traces on PC boards. Other than the speeds, it's all the same. On a PC board, which is where I make my measurements, the width and thickness of the traces can change. The surface roughness is important. The distance to the underlying ground plane can change. All of these cause exactly the same effects you are seeing. If all you are interested in is the first 5 usec, or so, you should change your Time/div to 1usec/div or so, thus zooming in on the signal of importance. The rest is about measurement techniques, and you should talk to other people making these same kind of mechanical measurements. Al Disclaimer: For more reliable response, you should consider calling your local Agilent Technical Call Center. The Agilent Forums are monitored on an "as available" basis, and aren't necessarily the fastest way to get technical questions answered. |
|
|
|
|
|
|
|
nvywyerwer 发表于 2019-2-19 13:33 为我的无知道歉,但是你的意思是时间/格? 什么是div? 你知道我在哪里可以改变dso-x 2002a中的那个规格吗? 干杯。 以上来自于谷歌翻译 以下为原文 apologies for my ignorance but wat do you mean by time/div ? what's div? Do you know where I can change that spec in dso-x 2002a? cheers. |
|
|
|
您需要花些时间来了解您的测量仪器,特别是示波器。 时间/格指定范围的水平比例,特别是屏幕上每个垂直分区之间的时间。 在屏幕的右上方,它表示5.000us /,这意味着屏幕上的每条灰色垂直线(称为刻度或分区)代表5个usec。 您可以通过转动“水平”部分中的大灰色和白色旋钮来调整此值。 您显然已经找到了水平平移旋钮(小灰色和白色旋钮),因为您已将参考点(填充橙色三角形)21.20 usec移动到左侧。 人 以上来自于谷歌翻译 以下为原文 You need to take some time to learn about your measurement instruments, specifically the oscilloscope. Time/div specifies the horizontal scale of the scope, specifically how much time is between each of the vertical divisions on the screen. Towards the upper right of the screen it says 5.000us/, which means that each of the gray vertical lines on the screen (called graticules or divisions) represents 5 usec. You adjust this by turning the large gray and white knob in the "horizontal" section. You have apparently already found the horizontal pan knob (small gray and white knob) because you have moved the reference point (filled orange triangle) 21.20 usec to the left. Al |
|
|
|
nvywyerwer 发表于 2019-2-19 14:13 那只是规模。 我知道已经没有知道“时间/格”这个词了。 我现在的问题是:5us的第二次“冲动”是什么? 我敢肯定这不是一种冲动,因为只有一种冲动而且它是0,但第二种是奇怪的,我没有承担。 此外,我应该在同一时间看到一个反射,我没有,因为有振幅的峰值(即使换能器没有连接到样品并指向空气)。 干杯。 以上来自于谷歌翻译 以下为原文 It is just the scale then. I knew that already just haven't aknowledged the term 'time/div'. My question now is: What's that second 'impulse' at 5us? I'm sure it can't be an impulse because there is only one impulse and it is at 0us but that second one is something strange that I don't undertand. Besides, I should see a reflection at that exact same time which I don't because there's that peak of amplitude (even if the transducer is not connected to the sample and pointing at the air). Cheers. |
|
|
|
5usec处的“脉冲”只是1 cm处阻抗变化的反映,您之前指出应该存在。 之后的一切都是样本内部的反射,或者来自内部不规则的两侧。 范围不是魔术。 它只是给你数据。 由你决定它意味着什么。 人 以上来自于谷歌翻译 以下为原文 The 'impulse' at 5usec is just the reflection of the impedance change at 1 cm, that you previously noted should be there. Everything after that is the reflection from inside the sample, either from the sides of from irregularities inside it. The scope isn't magic. It's just giving you the data. It's up to you to figure out what it means. Al |
|
|
|
只有小组成员才能发言,加入小组>>
1142 浏览 0 评论
2323 浏览 1 评论
2118 浏览 1 评论
1988 浏览 5 评论
2861 浏览 3 评论
883浏览 1评论
关于Keysight x1149 Boundary Scan Analyzer
651浏览 0评论
N5230C用“CALC:MARK:BWID?”获取Bwid,Cent,Q,Loss失败,请问大佬们怎么解决呀
755浏览 0评论
1453浏览 0评论
1144浏览 0评论
小黑屋| 手机版| Archiver| 电子发烧友 ( 湘ICP备2023018690号 )
GMT+8, 2024-10-21 14:30 , Processed in 2.132340 second(s), Total 94, Slave 76 queries .
Powered by 电子发烧友网
© 2015 bbs.elecfans.com
关注我们的微信
下载发烧友APP
电子发烧友观察
版权所有 © 湖南华秋数字科技有限公司
电子发烧友 (电路图) 湘公网安备 43011202000918 号 电信与信息服务业务经营许可证:合字B2-20210191 工商网监 湘ICP备2023018690号