When should one get concerned from a report of ppm of iron in the oil? Is there a standard "numbering" scale of ppm of metal?
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Hydraulic system?
engine Oil?
Gear oil?
???
engine Oil?
Gear oil?
???
Sorry.
Gearbox.
Gearbox.
Sorry but no fixed ppm limits for Fe on 'gearboxes'.
How many gearboxes (size and power)are there in different applications and environments.
Also there are additional techniques for assessing wear with ICP Fe being only one, Particle quantifier and DR Ferrography will help, but in the end a series of trended results is the only way to establish when troubles are nigh.
How many gearboxes (size and power)are there in different applications and environments.
Also there are additional techniques for assessing wear with ICP Fe being only one, Particle quantifier and DR Ferrography will help, but in the end a series of trended results is the only way to establish when troubles are nigh.
If the gearbox is new, the rate of wearing in the initial operating hours will be more.
Wear rate should be trended and looked at holistically together with other results rather than individual limits looked at alone. Also be aware that certain techniques used to ascertain PPM levels only detect certain size particles (smaller than about 8-10 microns) so you could have a severe or advanced wear situation but a low iron level. This is where the accompanying analysis results like PQI come into their own.
Thanks for the excellent info.
We have a gearbox that is showing signs of a potential problem, vibration wise, but seems, from the info you guys/girls have given me, the ppm results from the oil analysis is ok. The ppm of iron in the report was only 10, which is up from 2 six months ago. This is a 500% increase but the number is low or so it seems. Am I thinking correctly?
We have a gearbox that is showing signs of a potential problem, vibration wise, but seems, from the info you guys/girls have given me, the ppm results from the oil analysis is ok. The ppm of iron in the report was only 10, which is up from 2 six months ago. This is a 500% increase but the number is low or so it seems. Am I thinking correctly?
One of the things you should consider is that standard oil analysis will only pick up particles less than 10 micron. If you have a major failure occurring which is creating large wear debris then it may not immediately become apparent. Usually there are small particles visible to the eye in the sample if this is occurring.
If visible particles are present then conduct a test which dissolves the metal and then calculates the total iron reading.
Regards,
Rodney Fitzpatrick.
If visible particles are present then conduct a test which dissolves the metal and then calculates the total iron reading.
Regards,
Rodney Fitzpatrick.
Dear Jraquel,
Your mail is interesting as it show alertness and that is the basic of any condition monitoring excercise.
This forum has also rightly pointed out that analysis and conclusions should be based on trending. More important new equipment throws up more wear and this stabilizes over a period of time, hence trending enables decision making.
As pointed out by you, we need to be a bit cautious on using "percentages," as an increase of Fe from 1 ppm to 3 ppm is 200% but this must be taken with a pinch of salt. In short ppm in 100's is a cause for alarm.
Hussam
Your mail is interesting as it show alertness and that is the basic of any condition monitoring excercise.
This forum has also rightly pointed out that analysis and conclusions should be based on trending. More important new equipment throws up more wear and this stabilizes over a period of time, hence trending enables decision making.
As pointed out by you, we need to be a bit cautious on using "percentages," as an increase of Fe from 1 ppm to 3 ppm is 200% but this must be taken with a pinch of salt. In short ppm in 100's is a cause for alarm.
Hussam
a variance of 2 ppm to 10 ppm is scatter for me, due to our sampling technique.
However, since you are seeing vibration issues, I'd suggest a ferrogram.
If I was really concerned, I'd have Herguth run a AFA, Automated Feature Analysis, on their SEM.
A few hundred well spent if you really have a problem.
However, since you are seeing vibration issues, I'd suggest a ferrogram.
If I was really concerned, I'd have Herguth run a AFA, Automated Feature Analysis, on their SEM.
A few hundred well spent if you really have a problem.
quote:When should one get concerned from a report of ppm of iron in the oil? Is there a standard "numbering" scale of ppm of metal?
Hi Jraquel
As you can note for the other replies the 50ppm metal type analysis is restricted to < 10 µm and this test was not designed for gear drive wear it was designed for engine wear where the lubricant is well filtered,
When monitoring gear drives particle count and PQ are the most inportant followed closely by viscosity and water,
the ppm of metals is an the last one you check when the afore mentioned show irregularities,
VA require "damage" to show changes and you already have a change in the VA signal,
If this were a drive I was monitoring I would be checking the wear debris under a microscope so I was sure of what was happening,
Oue web site has this subject set out as a mini report so the spectrographic analysis is compared with micro images of the wear debris under "WDA ICPO & RDE"
Regards
Rob S
www.rttech.com.au
You may also check if you have a magnetic drain plug or a used oil filter you can cut open to look for additional iron.quote:Originally posted by jraquel:
Thanks for the excellent info.
We have a gearbox that is showing signs of a potential problem, vibration wise, but seems, from the info you guys/girls have given me, the ppm results from the oil analysis is ok. The ppm of iron in the report was only 10, which is up from 2 six months ago. This is a 500% increase but the number is low or so it seems. Am I thinking correctly?
