Choosing a microscope 1

[CRMagruder]

Hi,

I am a mechanical engineer / welding guy with just enough metallurgy experience from my last job to be called the "expert" in my present job.

I need to buy a reflected-light microscope for some metallography work. I will be using BF,DF, DIC and Pol observation methods. I have quotes from Nikon (Epihphot 200), Olympus (GX-51) and Zeiss (Axiovert 40 MAT) dealers / distributors. They are all about the same price and lead time. I have not seen any of these instruments or used them, so all I know about them is what the sales guys tell me and what I read in the literature. There is nothing that jumps out at me and says 'this is the best choice'. They all appear to be basically the same.

With a digital camera and some software, this will be about a $30K purchase, which is a lot for my company. I want to make a good choice since I will have to live with it for years to come.

Do any of you have experience with these instruments (or others)? What about representation? I'm on the west coast.

Please share your opinions!

Thanks in advance for your time.

 

[CoryPad]

Any of the three (or a Leica DM ILM) will provide decent optical performance and be trouble-free for years.

Personally, I would choose the Zeiss of the three you mentioned, although I think the Leica is of similar quality. I much prefer the ergonomics of the German microscopes when compared with the Japanese models.

You needn't worry about representation. The microscopes shouldn't have any major mechanical failures, and phone/email/Internet should help you if you need to buy new lenses, etc. You can always get a maintenance contract for yearly cleaning, etc.

I highly recommend getting a demonstration of the equipment before purchasing, especially the SOFTWARE! That will be your interface with the machine and its output.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[dbooker630]

I agree with CoryPad about understanding the software portion. As far as makes, the Olympus GX-51 is an excellent machine that I strongly considered at our company before looking for less expensive options.

I used a Zeiss Axiomat and a Nikon Epiphot for many years at my old job and they worked great. I now still use an old AO Metallograph but it's very limited as far as digital is concerned.

My major need was digital photography, and I accomplished that by fitting a Pax-Cam to a Leitz Ergolutz. The Paxcam also fits my Wild stereomicroscope and the old AO as well.

Definitely secure a contract from a reputable optics service. I'm not sure who is on the west coast but in the midwest HiPoint Optical is a good choice.

 

[arunmrao]

I go along with Corypad's suggestion. The German models are a shade better than the Japanese. In the past (before reunifaction of Germany) there was from East Germany Carl Zeiss Jena model. This was as good as the Carl Zeiss,but was cheaper by 30%.

Maintenance of these optical microscopes has never been an issue,if placed in a clean dust free room.

Look at the compatibility for taking good quality pictures and viewing on a large screen.

" All that is necessary for triumph of evil is that good men do nothing".
Edmund Burke

 

[swall]

I would do a "test drive" of the candidate microscopes just to make sure you like the ergonomics if you are the one that will be the main user. Also review the optical equipment layout to see if it is easy and convenient to use the various illumination and imaging modes. The sellers of the equipment should be willing to bring in a demo unit or they will have a site you can visit to see the equipment.

 

[EdStainless]

You do need to require a test drive, even if it means you taking a few flights.
The two things that I would focus on in the test are:
1. ease of changing illumination modes
2. ease of software operation.

Make sure that a day or two of on site software training is included in your purchase price. None of this stuff is intuitive.

If I ever buy another scope it will either be a Zeiss or a Leica. The Japanese make some very nice $10k scopes, but in the big league I would go German.

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[CRMagruder]

Thanks for all of your input and ideas. I thought if I asked for your opinions I would get some! I really appreciate it.

I especially appreciated dbooker630's remarks about the Pax-Cam. The Olympus sales rep wants to package his scope with the Pax-Cam camera and Pax-it software. He says that the software sold by the microscope companies is made to fit all sciences, and so they become more complicated packages. Whereas Pax-it is geared more towards metallography and works really well for those users.

I am kind of in a hurry since I'm starting a project where I have a lot of specimens to look at and document-- and I am getting sick of the cheesy stereomicroscope that I have been using. Your advice about demonstrating each one is will taken. I will do this even if it means traveling some. It is better to know I made the right choice than to always wonder...

I asked all the sales guys why I should choose their scope over the other ones. The two representing the Japanese brands told me that the Zeiss scope will have "more knobs" and adjustments that are nice if you use it every day, but are also more work if you are an occasional user. Except for the present project I'm working on, this instrument will be occaisionally used by myself and others in the company.

As for the ergonomics, all of the instruments have the focusing controls and stage x-y movement control near the bottom of the base, so one does not have to move your hand around a lot to get the view you want. For those of you that prefer the German instruments, can you comment some more about this?

I am interested in hearing any more remarks you have about changing from one observation method to another. It seems as though each manufacturer has a different way of getting the sliders or prisms in and out of the light path. Do any of you have experience with these microscopes that you can comment on? In addition to the software, this will be an important part of the demonstrations.

Thanks again for your input!

 

[CoryPad]

I think Pax-It software has major flaws, is overpriced, and the customer service is poor. The software itself is usable, but I wouldn't call it "geared for metallography" or that it works well.

The "more knobs" on an Axiovert will not make it difficult to use the microscope. The basic operation of coarse and fine focus, stage movemement, and lens changing aren't affected. The extra features are just for more specialized applications.

I am not sure I can convey adequately my preferences on the German microscopes' ergonomics. It is more than just the position of each control (which is still best on the Zeiss and Leica microscopes, in my opinion). It is also about the feel while moving each control (lens, stage, focus). Similar to automobiles, the Japanese models have controls that move with very little force, while the German models require a little more effort. The tactile response is a personal preference, but real nonetheless.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[EdStainless]

My comment about changing modes goes back to my days of using pol and NIC to differentiate secondary phases. An some scopes the jump between pol and NIC may take three or four actions (leavers, slides, knobs, whatever). This gets old fast and it is hard to recall six months latter.

I agree with Cory. It is personal opinion, but I like the feel of stiffer controls. I can tell when something clicks in without having to look.

We have our scopes on an annual cleaning/servicing contract. Worth it to make sure that all is in order.

= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[dbooker630]

Regarding the Pax-it, I can't say I've had the same negative experiences. Yes it is very expensive but when compared to buying a new microscope on a budget it was a bargain. I bought our Paxcam through Leco and they have been very helpful.

Typically at our company we metallurgists are on the floor a lot so we don't have time to play around in order to take a photograph, we want it ready at all times. We had Leco load up only the features we really needed. The image analysis works well also.

Maybe I feel spoiled now that I no longer have to take polaroids or steady an old Mavica over an eyepiece to take a snapshot!

 

[CoryPad]

dbooker630,

Based on your description of your work, I believe we have different needs for Pax-It. I am in a research lab and I need many capabilities. Also, I use Pax-It but not a Pax-Cam, which has contributed somewhat to my negative experiences with MIS (the manufacturer of Pax-It and Pax-Cam).

Of course, Pax-It is lightyears beyond Polaroid instant photography. I shudder everytime I think of the wasted time, effort and money I have spent with Polaroids. However, I think the microscope/camera manufacturers' own software usually is better than Pax-It, and I think CRMagruder should try and look at what a Zeiss camera/software package can offer compared with Pax-It.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[dbooker630]

Cory,

You're correct, my primary focus is manufacturing support. One other machine that I looked at was the VHX-100 and -600 digital microscopes sold by Keyence that I believe are made in Japan. At $40K for the entry level unit with a few options it was way out of my range, but it offered numerous features that were beyond my normal needs. I would be interested in any feedback on this type of scope.

Darren

 

[CRMagruder]

Thanks again for your continued discussion and insight into this subject. I have contacted the sales guys about demonstrations and they are happy to set this up.

Are you guys aware of any trade shows coming up where I could get a look at all the instruments at one place and time?

Most of my work will be for failure analysis, design / process improvement with a small amount manufacturing support. I really appreciate your opinions about using the instruments and software in your environments.

Thanks,

Chuck

 

[TVP]

I had a demonstration of this microscope, and evaluated several different types of parts, lighting, etc. I feel that this microscope offers some innovative features, such as flexibility of lighting options, easy configuration change for viewing at different angles without moving the part or fixture, and relatively easy software usage. However, it is not really a metallurgical microscope-- it is not inverted, it does not have options for darkfield illumination or DIC, and I am not sure how good the optics are at magnifications greater than 1000x.

Where I see this microscope as being most effective is for users that do not want to spend money on multiple microscopes: a stereomicroscope, a separate metallurgical microscope, and a scanning electron microscope. It offers features of all three of these microscopes, but cannot duplicate what each of these instruments can do individually. If you have only $40,000 to spend, this one instrument can do more than any of the above mentioned can. One thing to keep in mind is that they have some good information on their website, but it is not yet detailed with many metallurgical/materials applications.

 

[Welder4956]

If you can wait till August, you should be able to check out different manufacturers at the 2007 Microscopy & Microanalysis Meeting in Ft. Lauderdale.

http://microscopy.org/MMMeetings/MM07/

 

[Maui]

Last year at about this time I was actually in the very same position that you describe. Our lab needed a new microscope to replace the outdated instruments that we were using, and I contacted Olympus, Nikon, and Zeiss. Although I called Nikon several times, and left messages each time that I called, they never called back. Since they refused to reply to my inquiry when it was obvious I was interested in becoming a customer, I assumed that their custiomer service would be about the same in terms of their level of responsiveness. I moved on.

This narrowed the field down to Olympus and Zeiss. I spoke with the sales reps from both companies, and each agreed to provide me with a demo model for use in my lab prior to making a decision to purchase. I informed them each that I had contacted the other, so that there was no illusion on anyone's part on what I was doing. I was interested in buying the best instrument for my application. I tried one of the inverted GX series microscopes from Olympus first. I felt comfortable with this microscope, but was not thrilled with the optics. They were good, but at the highest magnification where the quality of the optics is most important, I noticed more abberrations in the images than I normally saw in the old Nikon scopes that we had been using. When I asked the sales rep how the objective lenses were manufactured, he informed me that the objectives were finish ground by an automated machine. They were not finished by hand.

When I brough the inverted Zeiss Axiovert in for demo, I was impressed with the quality of the objectives. They were clearly superior to the objectives that were used on the comparably priced Olympus microscope. I also asked the Zeiss sales rep how the objective lenses were prepared, and he informed me that the lenses were finished by hand in Germany. It showed. They provided crisp, clear images at magnifications as high as 2500X. I have used this scope on almost a daily basis for the past year, and do not regret the decision I made to purchase it. It was money well invested. The only microscope that was comparable in terms of the quality of the optics and construction was a Zeiss microscope that I had used previously in graduate school years before. They make a top notch instrument, and I would strongly recommend their microscopes.

Maui

 

[CRMagruder]

Thanks Maui for the great post and reccomendation.

The Nikon representation is not as good in my area as is the Olympus and Ziess, so the Nikon instrument is dropped from the candidates in my case as well.

So I will be evaluating the Olympus microscope next week and the Zeiss the week after.

I am curious if you are aware of a method for someone who does not use a microscope every day for evaluating the optics. Is there some sort of reference scale, pattern or sample that could be used to compare one set of optics to another? The highest magnification I plan to use will be 500X (50X objective).

The other thing I would like to learn about is the difference between hand and machine finishing on the objectives. I cannot imagine that something as precise as ground glass could be improved by hand work. I would have thought that the glass finishing process would only be improved by more accuracy in the machine tools that perform the work. If you can point me to a web site to learn more about this, please do. I will ask the sales guys if they can explain more about this as well.

Thanks again for your input!

Chuck

 

[CoryPad]

You can learn a little more here:

http://www.microscopyu.com

I think the best way to check the microscope is to use your day-to-day samples. Go through the magnifications and you will be able to tell if they are good enough for you. There is no need for a special sample. I think any steel should work - just etch with nital and look at the grain boundaries if there aren't any other features of interest.

I recommend highly that you get a 100X objective for a total magnification of 1000X. This is usually the upper limit for visible light microscopy and you never know when you may want to look at some small welding defect/inclusion. This will be a standard lens and won't be that expensive.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Maui]

Hand lapping is a preferential method for high tolerance finishing operations where the surface quality of the part is critical. Machinisits often hand lap steel parts that require such a finish. See

http://en.wikipedia.org/wiki/Lapping

and

http://www.surfacefinishes.com/lapping.html

I would also suggest that you use the day to day samples that you will be evaluating to judge the accuracy of the optics. Focus on the fine detail that you see in these samples at the highest magnification, and determine how clearly you can discern the outline of these individual features. The quality of the optics will be one of the factors that limits your capability to perform an accurate metallographic examination. For the Zeiss microscope, I purchased the following objectives with the Axiovert 200 system:

http://www.edmundoptics.com/US/onlinecatalog/displayproduct.cfm?productID=2814

They have performed flawlessly.


Maui