Hey,

I am using a Vickers particle counter and I was getting good results ~16/12/10 area. This is a 60 gallon resevoir with new oil utilizing a 1 Micron filter cart. After cleaning a few more machines suddenly I realized that it was taking longer to get lower and now after running 8 hours the particle counter is reading a consistant 20/11/0

I am trying to find out if it is the element or particle counter acting up. I haven't sent oil out to an outside lab as of yet. I am just wondering the 0 in the 14 Micron category is really throwing me into thinking it is a particle counter problem. Anybody have any ideas??? Thanks

I am wondering if I have an element problem, or if it is a particle counter problem.

Always try the cheap and easy fix first. Replace your filter element.

..and then look in to other disturbing factors:
- Air bobbles
- Water content

that might interfere your results.

And of course: When was the APC calibrated....?

I see a lab check absolutely crucial in this situation. Actually, in my opinion, occasional lab checks (scheduled once or twice a year or whatever time you set) of all field instruments should be a part of the program, regardless of what they measure. Calibration is fine (on the field or at the manufacturer’s facility), but still, an outside reference (calibration check) is necessary to make sure all is good. You will not save any money by not doing it, because without it, you would never know if the reading you see is the right value or at list in a ballpark of the real value.

Try taking a sample before and after the filter to see if the results differ, might help to eliminate something.

The problem you describe of taking longer to reach target levels and extended filtering time indicates a loaded up filter. Filters elements require frequent changing or cleaning (if cleanable).

I agree that periodic calibration by the manufacturer or an authorized service facility and frequent results vadidation by sending samples to an outside lab are good practices to maintain validity of your results.

I wanted to know if you had the issues resolved with your particle counter. I actually work directly with the company that manufactures the unit for Vickers and might be able to help you out. I can also do bottle sampling with our unit and show you the ISO we get.

Our oil supplier did a comparison test which proved that the particle counter is affected by:
Antifoam additive, air, water, etc.
So the more reliable test is the patch test.

ISO 32 Hydraulic oil....x/y/z.......x/y
Particle counter........22/21/19....21/19
Patch test..............15/13/10....13/10
ISO 4406 Laser..........19/17/14....17/14

ISO 68 Hydraulic oil
Particle counter........19/16/12....16/12
Patch test..............17/15/12....15/12
ISO 4406 laser..........21/20/15....20/15

Frank

quote:

Originally posted by macabf:
Our oil supplier did a comparison test which proved that the particle counter is affected by:
Antifoam additive, air, water, etc.
So the more reliable test is the patch test.

ISO 32 Hydraulic oil....x/y/z.......x/y
Particle counter........22/21/19....21/19
Patch test..............15/13/10....13/10
ISO 4406 Laser..........19/17/14....17/14

ISO 68 Hydraulic oil
Particle counter........19/16/12....16/12
Patch test..............17/15/12....15/12
ISO 4406 laser..........21/20/15....20/15

Frank

Frank. How come they did not try microscope count? That is, according to me, the most reliable test when done by an experienced operator. Patch test is only for screening / on site tests.

Agree with most of what has been said, and coincidently I am writing about such an issue at the moment. Silicone anti foam additive is perhaps the most frustratin error in APC data as it is recorded by the APC but isn't on the membrane as it passes through!

Agreed microscope counting is the most reliable method but it requires skill and time. The patch test may all be that is needed be needed if the requirement is to see whether the Required Cleanliness Level (RCL) has been reached. Note that this parameter has not been mentioned. If the purpose is certification then microscope counting is the only way.