Microscope for engine oil analysis

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Niklas
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Microscope for engine oil analysis

#1 Post by Niklas » Wed Aug 26, 2020 11:20 am

Good day,

I'm a complete beginner in microscopy and need some help.

I'm embarking on a project to analyse engine oil for wear particles. The particles are suspended in engine oil in the size from 1um and up. I need to be able to see if they are round/flat and maybe color(copper/brass/steel etc).

My idea is to put a drop on a glass and use illumination from below.

Will this work? Any suggestions to approach is very welcome.

Further, What microscope should I be looking for? I'm thinking second hand good quality that have some re-sell value. I'm not looking to thinker with microscopy gadgets/technology but just a tool to get the job done. It would be nice if there is a way to take pictures also but not necessary.

There is an Olympus cx23 (or CH 20 or BH2) for sale not far from me, will it do the job?

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75RR
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Re: Microscope for engine oil analysis

#2 Post by 75RR » Wed Aug 26, 2020 11:57 am

.
The quote below is from this link: https://www.machinerylubrication.com/Re ... errography
Analyzing the size, shape, color, magnetism light effects and surface detail of wear particles, a skilled analyst can paint a picture about the nature,
severity and root cause of abnormal wear. This information enables maintenance to implement effective corrective action.
Given the above list I would have thought a Transmitted Light Microscope would be more useful or at least one with long working distance objectives to be able to use side lighting.
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EYE C U
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Re: Microscope for engine oil analysis

#3 Post by EYE C U » Wed Aug 26, 2020 12:53 pm

Do you have a filter cutter like this yet?
https://www.summitracing.com/parts/sum- ... gIqr_D_BwE


flush the filter with some gas then cut it open. all your wear will be in the filter

Niklas
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Re: Microscope for engine oil analysis

#4 Post by Niklas » Wed Aug 26, 2020 1:15 pm

Thanks.

Correct me if I'm wrong but all the microscopes I mentioned above are Transmitted Light Microscope?

Another question: To be able to see details of a 1um particle the optics need to have good resolution. Is the 1980's optics good enough or should I aim for newer?

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Re: Microscope for engine oil analysis

#5 Post by EYE C U » Wed Aug 26, 2020 1:39 pm

even the new cheap optics i think are better or as good as the older...i just bought some 15 dollar eyepieces and they kich my old zeiss ones to the curb..

EYE C U
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Re: Microscope for engine oil analysis

#6 Post by EYE C U » Wed Aug 26, 2020 1:42 pm

you will want a top light for solid objects otherwise you will only see their shadows ...
IMG_8021.jpg
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Scarodactyl
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Re: Microscope for engine oil analysis

#7 Post by Scarodactyl » Wed Aug 26, 2020 2:01 pm

EYE C U wrote:
Wed Aug 26, 2020 1:39 pm
even the new cheap optics i think are better or as good as the older...i just bought some 15 dollar eyepieces and they kich my old zeiss ones to the curb..
This is incorrect.

Your comment about Zeiss eyepieces in particular is odd (not to get too far off topic but the zeiss eyepieces are an integral part of the optics).

Microscopes from the 80s are still good now if they were good then. There have been incremental advancements since but mostly at the top end where amateur budgets rarely reach anyway.

75rr meant an episcopic (reflected light) microscope rather than transmitted.

Niklas
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Re: Microscope for engine oil analysis

#8 Post by Niklas » Wed Aug 26, 2020 2:39 pm

Could this fit my needs? It's a BH2 with what I believe is a reflective light source.
https://www.leboncoin.fr/equipements_in ... 56878.htm/

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Re: Microscope for engine oil analysis

#9 Post by Tom Jones » Wed Aug 26, 2020 2:47 pm

Is the microscopic analysis you're planning to do in addition to, or in lieu of normal oil (spectrographic, etc.) analysis??

Among others... https://www.blackstone-labs.com/tests/s ... -analysis/

I have an oil analysis done, cut the oil filter and inspect the element each time I change oil on my airplanes. I think that tells me a lot more than a direct visual observation of microscopic particles, and anything of immediate concern is visible macroscopically anyway.

While you can probably discern the different types of metal to some degree, I suspect it would require quite a bit of training and experience to be reasonably reliable, and maybe a few special techniques you won't have access to. You will also need a thorough understanding of the alloy composition for the components of the engine structure itself. Not to mention the difficulties in quantization for serial analysis of normal wear or failure patterns over time.

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Re: Microscope for engine oil analysis

#10 Post by Niklas » Wed Aug 26, 2020 3:06 pm

In addition. I'm planning to have a good idea of the number of solid particles(and their size/shape) and see how reduction of this affects the oil analysis.
Among other things I would like to see how clean new oil is and the result after filtering 1,2,3,4 etc times.....testing different filtering techniques etc.

There is a lot of things I would like to investigate and the only way forward is to get equipment where I can see/quantify this. A microscope(I think) would be a very good start which will not cost an arm and a leg.

I need some equipment guidance since I'm new to microscopes and at first glance it looks like a jungle....

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75RR
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Re: Microscope for engine oil analysis

#11 Post by 75RR » Wed Aug 26, 2020 3:11 pm

Niklas wrote:
Wed Aug 26, 2020 1:15 pm
Correct me if I'm wrong but all the microscopes I mentioned above are Transmitted Light Microscope?
Sorry, meant to write Reflected, but a transmitted one with long working distance objectives might do as well.
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Re: Microscope for engine oil analysis

#12 Post by Hobbyst46 » Wed Aug 26, 2020 3:54 pm

Niklas wrote:
Wed Aug 26, 2020 3:06 pm
In addition. I'm planning to have a good idea of the number of solid particles(and their size/shape) and see how reduction of this affects the oil analysis.
Among other things I would like to see how clean new oil is and the result after filtering 1,2,3,4 etc times.....testing different filtering techniques etc.

There is a lot of things I would like to investigate and the only way forward is to get equipment where I can see/quantify this. A microscope(I think) would be a very good start which will not cost an arm and a leg.

I need some equipment guidance since I'm new to microscopes and at first glance it looks like a jungle....
If going to use an optical microscope, an image analysis software would be essential for particle analysis. There are many software packages that can do it. For example, as a minimum, a program to identify particles (say, above a pre-defined size, to exclude dust), define their shape, count them, calculate average diameter etc etc. Such features are basic and common and a free software like ImageJ will easily do it from the recorded images (one needs a camera on the microscope, naturally, but not a very sophisticated or sensitive one).

@75RR - a reflected microscope might be better to distinguish the color, if the color can be a reliable indicator of the type of metal (of which I do not know - the oil layer might distort the color maybe).

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Re: Microscope for engine oil analysis

#13 Post by Niklas » Wed Aug 26, 2020 4:01 pm

Hobbyst46 wrote:
Wed Aug 26, 2020 3:54 pm
Niklas wrote:
Wed Aug 26, 2020 3:06 pm
In addition. I'm planning to have a good idea of the number of solid particles(and their size/shape) and see how reduction of this affects the oil analysis.
Among other things I would like to see how clean new oil is and the result after filtering 1,2,3,4 etc times.....testing different filtering techniques etc.

There is a lot of things I would like to investigate and the only way forward is to get equipment where I can see/quantify this. A microscope(I think) would be a very good start which will not cost an arm and a leg.

I need some equipment guidance since I'm new to microscopes and at first glance it looks like a jungle....
If going to use an optical microscope, an image analysis software would be essential for particle analysis. There are many software packages that can do it. For example, as a minimum, a program to identify particles (say, above a pre-defined size, to exclude dust), define their shape, count them, calculate average diameter etc etc. Such features are basic and common and a free software like ImageJ will easily do it from the recorded images (one needs a camera on the microscope, naturally, but not a very sophisticated or sensitive one).

@75RR - a reflected microscope might be better to distinguish the color, if the color can be a reliable indicator of the type of metal (of which I do not know - the oil layer might distort the color maybe).
Thanks! I knew a software like that would be very useful but haven't started to look for one.

regarding color, I guess it's a simple matter of white balance against the oil color.

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Re: Microscope for engine oil analysis

#14 Post by Zuul » Wed Aug 26, 2020 4:07 pm

The simple answer to your question is, any “decent” compound microscope will allow you to observe the particles in oil. What qualifies as decent in new microscopes of Chinese manufacture is open to some interpretation, but you would be looking at something around $200-ish with 10x eyepieces and a 100x objective (1000x). That offers the highest realistic visible light magnification. Ignore claims of 2000x or 2500x from venders including eyepieces with magnification higher than 10x. The view is “bigger” but does not offer any improvement in resolution. Blame physics. A 1um particle is right at the lowest limit of visible light observation, so don’t expect to see more than a dot, and even that will require a bit of care in slide prep and good general technique.

If you want to enter the realm of microscopy as a hobby, there are very nice older microscopes available for less money than Chinese built offerings. They are as good or better, but you need to know what to look for (easily learned here) and be open to a bit of refurb. For a bit more money, used research grade scopes can be had that are far better quality, and offer a wide range of alternate illumination techniques when properly accessorized. The rabbit hole is deep, and you can spend as much as you want. For your usage, it’s not clear what techniques would give you useful information. If you aren’t too cost sensitive, it would definitely be beneficial to get something that can be upgraded with “epi” illumination (lit from above) at a minimum. That’s not uncommon for good used scopes, but don’t expect it on new scopes except for the most expensive models.

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Re: Microscope for engine oil analysis

#15 Post by apochronaut » Wed Aug 26, 2020 11:30 pm

You might consider using magnetic separation of the iron based particles and develop a method of quantifying those separately from the non-ferrous particles left in suspension.

Epi- illumination will be most useful as previously mentioned. Epi technique gets tricky down to one micron and the equipment is not as cheap usually , as diascopic equipment.

This seems somewhat akin to micrometeorite anslysis, although they are mostly much larger . However, I can see a great need for a lot of of precision separation. but it seems that your searching will be taking place after the oil is mostly gone. Any truly disolved material will need a different approach.

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Re: Microscope for engine oil analysis

#16 Post by PeteM » Thu Aug 27, 2020 12:19 am

Seems to me the ideal scope to aim for might be something like an Olympus BH2 to which you could add a reflected head and even relatively affordable reflected DIC. Nikon Optiphot is another option. If 1 micrometer is the smallest you need to see, a 100x objective would be enough discern shape. Reflected images at 400-1000x would likely give a good view of the surface, especially with larger particles. Best of all - you're already into oil immersion (that's a joke, weak one at that).

Could be a simultaneous combination of transmitted and reflected light would give the best images? With that setup you could do one, the other, or both. And if particle geometry makes some difference, the DIC might be helpful in better seeing surface geometry.

Many commercial trucking firms do routine oil analysis. Go to a commercial trucking oil-change operations and you could likely get some of your own samples send to a proper oil analysis lab for comparison. As Tom has already noted, spectroscopy is usually used for an elemental analysis.

FWIW, a cheap oil filter only catches particles above around 40 micrometers. It's the smaller particles than often accelerate engine wear.
Last edited by PeteM on Thu Aug 27, 2020 7:45 am, edited 1 time in total.

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Re: Microscope for engine oil analysis

#17 Post by apochronaut » Thu Aug 27, 2020 1:23 am

PeteM wrote:
Thu Aug 27, 2020 12:19 am
FWIW, a cheap oil filter only catches particles above around 40 micrometers. It's the smaller particles than often accelerate engine wear.
That and corrosion caused by acids that develop in engine oil.

Niklas
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Re: Microscope for engine oil analysis

#18 Post by Niklas » Thu Aug 27, 2020 7:50 am

This is my idea right now..
There is an CX23 for sale not far from me. I like the fact that it's new in box, so it will likely give me very little issues.
From a point of just finding and counting particles I think transmitted light would work best as this will give me black dots on a bright background.
Also good for image detection software.

For reflected light, will the CX23 work with an external light source? They state that the objectives are "long working distance" (10x:8mm 40x:0.6mm 100x:0.13mm) so I hope that is enough space for the light to be able to shine on the subject. Something that came to my mind, is it possible to replace one of the eyepieces with a light source?

Another thing, the eyepiece cameras that exist, are there any model which is the go-to one for good price/performance?

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Re: Microscope for engine oil analysis

#19 Post by apochronaut » Thu Aug 27, 2020 12:06 pm

Personally, I think you are barking up the wrong tree. If you are getting a really good price for it, then it might be worth a chance but only because the manufacturer has posted a picture of one with a vertical illuminator on it. I think it is an led fluorescence unit but it is a vertical illuminator nonetheless and works on a CX 23. I have no further information. Olympus doesn't make the microscope. They are made by Splendor Industrial in Shangdong, or at least that is the wholesale entity that interfaces with potential buyers.
The CX 23 is very expensive for what you get. They are about 1000.00 f.o.b. the supplier. It is a student microscope that in it's literature extolls it's virtues as though they are innovations. All of those virtues have been available in student microscopes from various makers for at least 20 years. Even led illumination has been common for around 7 or 8 years, if that is a virtue?
You are paying a big bag of bills for a brand name. There were microscopes built physically well, made 25 years ago, that had the same or better specifications that are available for 250.00 or less. Even some of the specs. aren't great . .6 mm isn't exactly super duper for a 40x and with student grade optics? It isn't going to be easy to do incident illumination with the objectives that close and they are flat bottomed.
There are a couple of fairly widely available scopes from the 80's/90's that were available with both epi and transmitted illumination . I would go for one of those, because that way you can use both no cover and cover corrected objectives and do a real job. A fully tricked out one of those will cost less than the CX 23. You are going to need about 600X to get any kind of qualitative analysis on particles that small.
If you are just in to quantitative analysis then save your bills , buy the cheapest stand you can find that works and then buy a couple of L.W.D. objectives to match the stand, 20X, 40X to start, real long working distance objectives : industrial ones are available from China very cheap, or some older ones . AO L.W.D. objectives with real working distance are frequently available with 1 to 2 mm w.d., cover slip corrected, a series 10 stand for less than 100.00 . You will save a lot of money get better results and you won't have a feather light, overpriced student microscope in your hands that was designed primarily so an 8 year old could get it off the shelf by themselves.

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Re: Microscope for engine oil analysis

#20 Post by Niklas » Thu Aug 27, 2020 2:57 pm

So, your saying the optics are not up for the job? Then I will continue looking for something else. Is there any information online which optics are good/bad or reviews etc?

I'm new to microscope equipment so if you can point me in the right direction (like who produces good optics....or what indicates a good optics) that would be good. Or even better, what would you choose? (ebay links for example).

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Re: Microscope for engine oil analysis

#21 Post by apochronaut » Thu Aug 27, 2020 3:57 pm

Not necessarily the optics Niklas but the set up and design of that little scope will quickly frustrate you . It is a school microscope.

Where are you located?

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Re: Microscope for engine oil analysis

#22 Post by Niklas » Thu Aug 27, 2020 6:20 pm

I live in France. For second hand I'm looking at ebay europe or the national leboncoin.fr.

If you can point me to a good setup(or idea of that) in the sub 500€ it would be super. I kind of need a starting point what to look for(and what to avoid). I don't mind that stuff is old per se but I do mind if I need to spend a lot of time to look for the whole system and /or if it will need extensive renovation/service.

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Re: Microscope for engine oil analysis

#23 Post by PeteM » Thu Aug 27, 2020 7:01 pm

I'd consider a used Olympus BHT or a Nikon Optiphot. Both of these have removable nosepieces and a wide availability of parts available used.

Start with a transmitted light (brightfield) scope with plan achromatic objectives - say Olympus DPlan or Nikon E Plan - since you think that just the shapes in silhouette will be most useful. Even better, but harder to find, would be a complete metallurgical scope (reflected light) based on the BH2 platform but also with a transmitted illumination system. This would do everything.

If you buy just a BHT or BHS or Optiphot -- and if you later want to see the surface geometry and particle colors you can easily add the parts to do that. Those will be a vertical illuminator and a set of lenses meant for epi illumination, such as Olympus MSPlan or NeoSPlan (they do darkfield as well and would need the right vertical illuminator - a BH2-RLA in this case). You could even add DIC prisms for reflected light - but buying a complete scope with the bits you want is usually cheapest.

Here in the US I could likely buy a complete brightfield BHT or Optiphot I for the equivalent of 300 Euro. Then, if I wanted the reflected light option the best bet might be an entire scope once used in semiconductor wafer or metallurgical inspection for maybe 250 Euro equivalent (but without DIC). Sell the second stand you don't need.

Leitz/Leica also made microscopes with both brightfield and reflected options, but they are harder to find here and harder to figure the right parts, given somewhat less documentation. There are good Zeiss options as well but I'd rate them 4th for ease of getting a complete system together with good optics. In Europe, maybe better luck.

My personal feeling is that you won't learn much by just the silhouettes of suspended particles and an approximate count. And maybe not much more by their color and surface geometry. So another option might be to buy the cheapest Olympus BH2 model or Nikon Optiphot model you can find and learn a bit. If it's a dead end you can sell it for about what you paid. If it's promising, you have a good start on the microscope you may want.

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Re: Microscope for engine oil analysis

#24 Post by 75RR » Thu Aug 27, 2020 8:03 pm

Here a a couple of microscopes worth having a look at.

Do wait for comments on them as to their suitability before jumping in.

https://www.ebay.co.uk/itm/Leitz-Labore ... ondition=4

https://www.ebay.co.uk/itm/Nikon-Laboph ... ondition=4

https://www.ebay.co.uk/itm/Leitz-Laborl ... ondition=4
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Niklas
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Re: Microscope for engine oil analysis

#25 Post by Niklas » Thu Aug 27, 2020 8:39 pm

Thanks for your help, I'm starting to grasp a few things.

So, after some hunting online I found that the Olympus system have plenty of stuff available. I feel that if I'm looking for parts(in the future) this system would be the easiest to live with, correct?

Two question about objectives.
The 'S' in MSplan I guess it means it's used for reflective light (is there as specific light path thru it?). I found zero for sale of these or the neo version, are they rare?
And, I guess I have to look for these objectives in the 160mm standard...the infinity won't work?

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Re: Microscope for engine oil analysis

#26 Post by 75RR » Thu Aug 27, 2020 8:45 pm

The Olympus BH 2 would be a good choice though not the only one. It is a bit rarer in Europe than in the USA

You will find that the 160 finite system is much cheaper than infinity (it is older) but in almost all respects is just as good.


It might be worthwhile looking to source a BH 2 from the USA, you will however have to take shipping and taxes into account.
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
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Re: Microscope for engine oil analysis

#27 Post by mrsonchus » Thu Aug 27, 2020 8:56 pm

Hi, I may have a 'scope that may suit you. It's an Olympus BHM with infinity objectives, Neo-Splan LWD-50x and Neo-Splan 20x, DPlans at 10x and 5x.
This 'scope is able to give incident and darkfield incident as it has the BH2 RL attachment. I'm just about to put it onto e-bay (U.K.) and it will probably go live later, as I plan to make the listing later tonight if I get a chance.

Here are a few images already taken, ready for the listing.
Image

Image

More images

Beautiful set of objectives, infinity Neo series,
Image

Image

Image

Image

Image

Image

Image

Just contact me if you'd like to know anything about it - or of course look out on e-bay in a couple of hours for it.
It's getting in the way in my tiny 'lab', but may be just what you need....
Last edited by mrsonchus on Thu Aug 27, 2020 9:08 pm, edited 2 times in total.
John B

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75RR
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Re: Microscope for engine oil analysis

#28 Post by 75RR » Thu Aug 27, 2020 9:01 pm

That is an interesting development!

Here is the brochure: http://www.alanwood.net/downloads/olymp ... ochure.pdf
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Re: Microscope for engine oil analysis

#29 Post by mrsonchus » Thu Aug 27, 2020 9:08 pm

Hi 75' - quite a coincidence! When I saw this thread a couple of days ago I mentioned it to my Wife who said I should sell it on and stop moaning about space!

So, finally I'm getting a listing built. But it may be O.K. for Niklas, it's in lovely working condition.

Oh yes, here's a link to a set of images on my G-Drive including some images taken through the 'scope with my 5mp Toupcam plugged into an eyepiece and using Toupview to capture the images....
Last edited by mrsonchus on Thu Aug 27, 2020 9:50 pm, edited 1 time in total.
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Re: Microscope for engine oil analysis

#30 Post by mrsonchus » Thu Aug 27, 2020 9:19 pm

Hi,

The BH-2-RLA-2 fitting also has an iris (field iris allowing the elimination of halos with the DF settings and N.A. matching presumably) with a BD drop-in filter I bought recently to go with it in the sale. There's an ND-filter too, that automatically flips in (and may be flipped-out again if preferred) as changing from DF to BF by pulling the 'puller' rod (or the other way, can't remember now and I only used it an hour ago!) to set the illumination level down a little to avoid glaring. Quite a clever set-up in fact, just a little too powerful for the sort of (Botanical) specimens I examine. I bought and added the specimen holder, as it came without one.
John B

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