Week 15

The end.
Instruction to the exercise can be found here (Polish version only).

Week 14

Almost finished... We completed all planned goals. Unfortunately, we have to cancel the measurements with usage of shear wave probes. It's caused by the lack of proper samples. The last thing to do is to write the instruction.

Week 13

Changes in conception...

Unfortunately, we made a cardinal mistake in our assumptions, so we can't compare the method of measurement of thickness using ultrasounds with classical caliper. But (thanks to our academic teacher) we fixed the procedure for measuring the attenuation factor. Now the results are satysfing. So the current list of tasks in our exercise consists a few points:

• determination of velocity of longitudinal and share waves (using different probes) in calibrating block
• determination of velocity of longitudinal wave (using different probes) in different samples
• determination of attenuation factor (using apropriate probe) in different samples

Next time we need to collect missing data (to be able to present some examples) and write the instructions.

Week 12

We determined the densities of several samples. It helped us to confirm that our results aren't similar to these taken from literature (attenuation factor, velocity of sound in material). But it doesn't prove that obtained values of eg. velocity of longitudinal wave are incorrect in general. We checked the calibration of probes using calibrating block. As it turned out, everything is set very well. As a conclusion we can say that some variances between values obtained from measurements and literature aren't similar but correct. We won't discuss this issue anymore. Now we need to focus on realizing the measurements of chosen physical quantities in different samples (thickness, velocity of sound) and checking that there's no further problems. We hope to be able to start writing instruction next week.

Week 11

Fortunately, this time everything went according to plan... but it doesn't mean that the results are satisfying. 

As it turned out, there's no difference between water and USG gel as a couplant. We supposed improved transfer of energy from the probe to the sample in case of using gel, but it doesn't happen. After testing couplants we spent most of the time trying to find the value of attenuation factor for different samples. The result are different than these published in literature (for aluminium and brass or copper). We decided to resign the measurement of mentioned physical quantity. Moreover, the problem of unidentified echoes is still open. We have assumpton that they come from the rear side of probe: the wave propagates through the probe, then it reflects, comes back and enters sample. As a result we observe fake bottom echo behind the correct one. But it's still unconfirmed.

After the consultation with academic teachers, we obtained some useful information concerning ultrasonic testing. Now we need to consider the possibility of producing additional samples with intentionally introduced flaws. It will give us a chance to expand the list of tasks for our exercise.

Week 10

Problems...
We wanted to add the measurement of sample thickness to the list of tasks in our exercise, but there are some difficulties with interpretation of data obtained from detector. For different probes and sample there are observable some unexpected echoes. They occur behind the echo from the bottom of the sample, so it's really confusing for us. We tried to figure out why they appear, but this problem is still unsolved.

Despite the facts described above, we confirmed the good correlation between sample thickness measured with caliper and ultrasonic detector (aluminium samples, normal probes, results based on bottom's echo and it's multiplicity). The plans for next week present as follows:

• considering the origin of 'strange' echos
• testing USG gel as the couplant (in compartion with water)
• measurements of attenuation factor (we need to prepare the external scale to determine the height of echoes because the original software has no this option)

Furthermore, we are invited for consultation with one of academic teachers, who will give us some advices and show samples with intentionally introduced flaws (it's possible to copy them in workshop).

Week 9

All ultrasonic probes are calibrated (except the one for surface waves). We also managed to do measurements of thickness for samples (probably) made out of aluminium. The results are encouraging. After comparing with data obtained by caliper, we found it as correct. The second measured thing was velocity of longitudinal waves. Our results are similar to the values taken from literature (only for ALU samples).

As you noticed, we got some delay according to scheme published two weeks ago. We hope to work more efficently next time.

Week 8

Easter holidays.

Week 7

We were asked for preparing schedule for the rest of the semester. It presents as follows:

21.04. – Easter holidays;

28.04. – measurements of: sample thickness, sound velocity, attenuation;

05.05. – continuation, checking created procedures;

12.05. – possible holiday due to Juwenalia (check on Wiki);

19.05. – testing different couplants, preparation of instruction;

26.05. – final tests and measurements, completing instruction;

02.06. – final presentation;

Week 6

We managed to finish research and collect a lot of useful information. While we were searching some different things, we noticed how extensive is the matter of ultrasonic testing.

At first, we planned to compile all found sources and publish our own text with essential knowledge. As it turned out, in the Internet there’s a complex base of physical and technical principles of UT (ndt-ed.org - education resources). This fact led us to changes in our concept. We agreed that there’s no sense to copy everything, especially that the content is protected by copyrights (however we would use it only for educational purposes). On the mentioned website there’s also a lot of valuable Java applications which cannot be transferred onto our blog. To fulfill the continuity and right order of things, we decided to set a link to the UT data base and give it to you ‘as it is’. Of course, we are aware of the knowledge stored there and we studied it carefully.

After couple of hours spent on searching the Internet, we obtained a huge set of links, presentations and articles. Most of them were completely useless to present the basics of ultrasonic detection, but a few we found as valuable. Appropriate links are also visible in the section ‘Theory’.

We would like to do develop theoretical side of our project, but it depends mostly on spare time availability. Unfortunately, we have been quite busy recently. In spite of that we should also remember about final deadline.

Updates...

As you surely noticed, we created another page, called 'Theory'. We will add there all the links and other materials concerning theoretical side of our project. We think that such a solution will ensure you comfortable access to these information (in opposition to searching different news).

Section ‘Authors’ has been also updated.

Week 4 / Week 5

As it was announced, we are working on the theoretical side of the project. There will be no news published until we finish.

Week 3

We do apologize for the delay. This week Justyna was absent, so I focused on searching different information concerning our device. Unfortunately, we are not able to download complete data base for the flaw detector. This force us to calibrate all of available heads. According to the manual I managed to do it with two normal heads. The rest will be calibrated next time.

We are asked for preparing the theoretical side of the exercise. It will take us about three weeks as I suppose. You can expect some equations, schemes and quotes included in next news.

Week 2

We are glad to communicate: it works! In contrast to last lab classes, this time everything went well. Nevertheless, we start this report (as it was announced recently) by placing the photo of the measurement site.

Measurement site
<<click to enlarge>>

In the foreground, there you can see the ultrasonic flaw detector CUD 10 (between the monitor and the keyboard). There are also cylindrical metal specimens, printed manual, water bottle, piezoelectric heads (on the blue notebook) and two racks (holders). In the background, there is visible older version of the ultrasonic detector but we don’t need it. As it was mentioned last week, the detailed description of the equipment will be given soon in separated news.

Concerning the progress made this week we can say that we are quite satisfied. The planned exchange of the computers was realized without any problem and all software was installed successfully. We have managed to run the first measurements which is encouraging for the future. However, the beginning wasn’t easy because the device manual it not helpful in many cases.

The measurement using ultrasonic flaw detector CUD 10 requires setting material of the sample and type of currently plugged head. Our device has built-in data base with different types of both. For the first test we chose normal head generating longitudinal waves. The sample was made of aluminium. To provide proper transmission of ultrasonic waves from the head to the sample we used water as a coupling liquid.  Additionally we tried to observe what happens in case when the coupling fluid is removed. The results were quite surprising. We expected significant attenuation of recorded signal (due to scattering of waves on the rough surface of the specimen) but there was no signal at all! It’s very valuable experience. On the ground of this observation Justyna figured out that it’s worth checking the influence of different coupling liquids on the recorded signal.

Actually, to be more strict, our measurement wasn’t fully controlled. The choice of the head and the specimen was determined by available data in detector’s register. There’s only a few files with necessary information so we need to download missing data to be able to use all of our heads and samples. If it would occur impossible, we plan to calibrate heads using method described in the manual. The problem regarding the specimens is more complicated because we don't know its composition. If we don’t find any notes about it, we will try to measure the speed of sound in each sample and compare results with the values published in literature to recognize the material.

Week 1

We are after the first session of work at laboratory. Unfortunately we have not completed all planned goals. There occurred some technical problems and we focused on solving them.

According to our plans from previous week, we have started from the review of available equipment. Details concerning this part will be given later in separated news. Be patient please. We have reorganized the measurement site to provide full comfort of work. Next week we plan to add here some photos to show you how it exactly looks like.

As it was mentioned we have not completed our plans for this week. The main reason of this situation was the problem with the software. Ultrasonic flaw detector CUD 10 (that we use) has an option to connect it with the computer via USB port. We tried to install necessary drivers in accord with the attached manual, but as it turned out the device and its software is compatible only with operating systems Windows XP and Windows 7. Ironically, the most of computers in our laboratory works with Windows Vista (the intermediate version of mentioned ones). Finally, after over two hours, we have found the computer which properly detects our ultrasonic device. It wasn’t so easy, because another PC with installed Windows XP also could not find our detector among its plug-in devices. We think that this problem was somehow related with Service Pack provided to operating system. The properly working computer is dedicated to exercise with gamma radiation. We need to exchange it. Of course it requires reinstall and copy all necessary software to another PC (to keep the site fully operative). This is the thing that we plan to deal with next week.

We wanted to launch the equipment and run first measurement. It didn’t happen because of the reasons described above. We hope that next time everything will go more efficiently. Meanwhile, we have downloaded up to date version of flaw detector manual.  It’s advisable to read it entirely for next session at lab. For this moment we know only the part, which is needed to use the ultrasonic device safely.

To sum up, we have realized:

• Organization of the measurement site
• Reading the manual (partly)
• Establishing the connection between the PC and ultrasonic device via USB

To do for next week:

• Swap the computers and copy all needed data
• Launch the equipment and run first measurements

Week 0

Introductory classes. From the list of available topics we have chosen ultrasonic testing of solids. For this moment our knowledge in this matter is quite poor so we are going to do some research. We hope to catch basics as fast as it is possible. This will help us to create the general concept of the exercise.

We have no details about the equipment available in the laboratory. Thus first of all we need to check the lab resources and condition of facilities. However, as far as we know, in the lab can be found a digital ultrasonic detecting device. Further information will be given when we obtain some details.
 

We hope to manage to organize the measurement site quite well and quickly. It is advisable to start measurements next week due to limited time of classes.

To sum up the plans for the next week are as follows:

• checking equipment resources
• reading detecting device manual
• organization of measurement site
• launching equipment
• running first measurements

    

Time to start

This website is an integral part of our academic project. The general concept involves publishing here a description of current progress of our work. If you are interested you can always skip into ‘Project’ or ‘Website navigation’ to find more details. For this moment information published there are incomplete but we will update it soon.

We are aware that detailed descriptions such as ‘we plugged wire A into port B’ are completely abstract, but these parts of posts are dedicated to our academic teachers and you can skip it.

The content of this website will be updated depending on spare time availability (at least once a week). We have decided to publish the blog in English but our mother tongue is Polish, so for sure here will occur some (especially grammatical) mistakes. We ask you for tolerance and feedback if you notice any confusion.

P.S. We invite you to visiting our blog regularly.