they typically contain thixotropic agents which give non drip properties. Most paints are deliberately formulated to have non Newtonian characteristics. So when you ask the viscosity of a fluid that takes 140 seconds to drain from a Ford B4, the chart writers and cup makers don't want you to hazard wild & unrepeatable extrapolated guesses … they want you to use a cup with a bigger hole :-)Ī. The charts tell you the viscosity of fluids that drain in 5-60 seconds, probably most accurately when the drain time is in the 20-40 second range. You're not finding the conversion factor that you're looking for because extrapolation can lead to huge errors and they DON'T WANT YOU TO EXTRAPOLATE. Although I am not an expert on this stuff, I am confident from simply reading this page, and looking at the several conversion charts on it, that your problem is the same as previously explained to Aniruddha and then explained again to Manikantan, i.e., that you have a cup that is designed to measure a lower viscosity fluid, and you are trying to use it to determine the viscosity of a higher viscosity fluid. From where are you all getting the factor 3.7 please tell me for the problem of manikantan. For non-Newtonian, Method ASTM D2196 should be used. Please remember that this ASTM method (D1200) covers the determination of Newtonian or near-Newtonian liquid materials. Kinematic Viscosity (cSt) = 3.85 (t - 4.49), where t is efflux time in seconds. As per the ASTM D1200, "Standard Test Method for Viscosity by Ford Viscosity Cup", the following formula is used to convert efflux time in seconds (unit s) to Kinematic viscosity (unit cSt.) for Ford Cup Number 4: Can you please try to re-cast your question in terms of the answers already supplied? Sorry, I understand that the information supplied is deficient for your needs in some way, but I don't know not in what way :-) Thanks!Ī. In light of the previous answers and referenced charts & tables, I am not fully understanding wherein the difficulty lies. I think the basic problem is that you are trying to measure a high viscosity liquid with the wrong cup for the job the first step would probably be to get a cup which is designed for higher viscosity liquids than the #4 cup.
Nor is there a single cup that allows good measurement of all possible viscosities. A Ford cup with efflux time "more than 200 seconds", is a meaningless way, way, off the chart extrapolation :-(Ī carpenter doesn't drive tacks with a sledgehammer, nor landscape spikes with his tack hammer he uses different hammers for different jobs. That is,Ĭentipoise = centistokes x specific gravityīut as previously explained to Aniruddha, you're using the wrong cup. It includes a chart by Euverard showing a conversion factor of 3.7 for the Ford #4 cup. On Amazon] as it has an excellent chapter on the subject of viscosity and its measurement with the various cups and devices. Please also try to also get hold of the ASTM Gardner/Sward "Paint Testing Manual" [affil. Method ASTM D1200 covers viscosity measurement with the Ford Cup. (commissions from your purchases make possible) September 1, 2009Ī.
Viscosity cps how to#
Please send us how to convert it in to centipoise. We are checking its time to empty the cup in seconds. note: Although you can buy "certified" Ford #4 cups I'm not sure that that quite answers Sushil's question.
I think it has wide range of useful information. Try - Viscosity conversion tables by Norcross Corporation. Can you correlate these parameters to the disagreement of the cups? How do I say that a particular #4 cup is faulty and should be discarded? Can anyone explain to me the reasons? I can verify the volume of cup and the dia of orifice. I find that Two cups - #4 cups never give the same results. According to the previously referenced chart at it looks like the efflux time for an F5 cup would be about 48 seconds. The viscosity which you are trying to measure is beyond the workable range of an F4 cup. Using a cup with a huge hole to measure the viscosity of thin liquids that will drain in a flash would be like timing a 100 meter sprint with a sun dial and using a cup with a tiny hole to measure the viscosity of very thick fluids would be like using a stop watch to time the lifespan of an elephant :-) Meghan's posting was from 3 years ago so he might not be around to answer.īut I think the basic issue is that there are practical limits to such rough conversions.
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