accuracy of viscosity measurements in cSt and SUS?

[1 FMF]

quick question:
what kind of resolution can viscosity measurements be made to in the cSt the SUS scales?

For instance, if an oil has a viscosity of 10.00 cSt at 100C, is another measured or reported value of 10.10 cSt basically the same thing? How about 10.25 or 10.5?

Is the cSt scale such that there is a high level of accuracy to 0.1 cSt? I ask, since most published numbers are to 1/10 of a centistoke. And I also notice the same for SUS, but the SUS scale has a lot more resolution per whole number (much like the Fahrenheit vs Celsius temp scales).
I've never done viscosity measurements, so I don't know.

 

[XS650]

quote:

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Originally posted by 1 FMF:
quick question:
what kind of resolution can viscosity measurements be made to in the cSt the SUS scales?

For instance, if an oil has a viscosity of 10.00 cSt at 100C, is another measured or reported value of 10.10 cSt basically the same thing? How about 10.25 or 10.5?

Is the cSt scale such that there is a high level of accuracy to 0.1 cSt? I ask, since most published numbers are to 1/10 of a centistoke. And I also notice the same for SUS, but the SUS scale has a lot more resolution per whole number (much like the Fahrenheit vs Celsius temp scales).
I've never done viscosity measurements, so I don't know.

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Accuracy depends on the type equipment, it's condition and the operator. 1% accuracy is nothing special, accuracy can be much better if the i$ a need for it.

 

[JonS]

I spoke with someone at a refinery about this, and they said at 100c it can vary from 9.5-12.0 for a xw-30. But what is published is just an average. Also, when the temp is at 99c or 101c it is drastically different. So these specs really don't mean much for judging an oil.