Volume correction due to temperature rise?
Volume correction due to temperature rise?
(OP)
Hi Guys,
I'll explain in detail... What I am doing is providing oil to an engine and then I want to measure the oil consumption. Prior to the test I will determine the volume1 and temperature1 (density1). After the test, I will determine the volume2 and temperature2 (density2). The problem is that the temperature at the beginning of the test is not the same as the temperature at the end of the test.
Can I use a simple relationship such as?
Actual Volume after test at initial temperature1 = Volume2 * (Density2/Density1)?
Basically I am converting my volume measured after the test to provide the volume at the initial density prior to the test so I can measure the actual consumption. I can't wait until the oil temperature to decrease, as this would cause too many delays.
Would this work?
Reference: http://w ww.osti.go v/bridge/p url.cover. jsp;jsessi onid=2C1C5 3377CFEECA C11F489E7E C283E17?pu rl=/101791 80-qGMb2h/
Thanks
Gabriel
I'll explain in detail... What I am doing is providing oil to an engine and then I want to measure the oil consumption. Prior to the test I will determine the volume1 and temperature1 (density1). After the test, I will determine the volume2 and temperature2 (density2). The problem is that the temperature at the beginning of the test is not the same as the temperature at the end of the test.
Can I use a simple relationship such as?
Actual Volume after test at initial temperature1 = Volume2 * (Density2/Density1)?
Basically I am converting my volume measured after the test to provide the volume at the initial density prior to the test so I can measure the actual consumption. I can't wait until the oil temperature to decrease, as this would cause too many delays.
Would this work?
Reference: http://w
Thanks
Gabriel





RE: Volume correction due to temperature rise?
Also, if it's possible, you can always use the weight which is independent of temperature. But you have to be able to weigh it all.
Charlie
www.facsco.com
RE: Volume correction due to temperature rise?
Hint - you could calibrate the whole thing as a unit, with a fixed, known initial volume of oil, and vary the temperature...
RE: Volume correction due to temperature rise?
I've been playing with the equation that the OP proposed, and since Volume * density =mass, then dividing that mass at T2 by the density at T1 seems to give you a volume at T1. I like it.
The change in density will be really small for the heat gain in an engine, but if that is the kind of precision your application requires, I'd say that your approach has a lot of merit.
David
RE: Volume correction due to temperature rise?
"I am sure it can be done. I've seen it on the internet." BigInch's favorite client.
http://www.youtube.com/watch?v=hpiIWMWWVco
"Being GREEN isn't easy." Kermit
http://virtualpipeline.spaces.live.com
RE: Volume correction due to temperature rise?
David
RE: Volume correction due to temperature rise?
FACS - Yes charle's law is for gases and pressure is constant as my reservoir has a breather (therfore atmospheric pressure).
btrueblood - I like your hint and that is very logical, but would cost us more money to do as we would have to buy a heater. It would be the perfect method though!
zdas04 - I agree that the change will be very small. It's oil and the density (or specific weight) will vary between 58 and 60 lb/ft^3.
BigInch - I will check it out ... The coefficient of thermal expansion of my oil seems to be 0.00045 (avg. between -40 and +300 degF). Now I am unsure what to do with this number, but I will look it up.
Thanks a lot guys!!
RE: Volume correction due to temperature rise?
RE: Volume correction due to temperature rise?
RE: Volume correction due to temperature rise?
Run the engine up to operating temperature. Drain the oil. Load up your set volume.
Run engine back to opearting and then drain. Compare weigths/volumes
Will this work??
RE: Volume correction due to temperature rise?
Charlie
www.facsco.com
RE: Volume correction due to temperature rise?
RE: Volume correction due to temperature rise?
1gibson - That's another possibility, but more costly for us.
With this, I'll stick to the original equation, and that will work well!!
RE: Volume correction due to temperature rise?
Just a thought.
I'm sure I saw a paper that taught this Law to students using oil. I could be wrong.
Charlie
www.facsco.com
RE: Volume correction due to temperature rise?
α= linear coefficient of thermal expansion 1/F[°]
Change in volume = original vol x 3α /F[°] * (T2-T1)F[°]
"I am sure it can be done. I've seen it on the internet." BigInch's favorite client.
http://www.youtube.com/watch?v=hpiIWMWWVco
"Being GREEN isn't easy." Kermit
http://virtualpipeline.spaces.live.com
RE: Volume correction due to temperature rise?
"I am sure it can be done. I've seen it on the internet." BigInch's favorite client.
http://www.youtube.com/watch?v=hpiIWMWWVco
"Being GREEN isn't easy." Kermit
http://virtualpipeline.spaces.live.com
RE: Volume correction due to temperature rise?
That's exactly what I will be doing, very simple!!
RE: Volume correction due to temperature rise?
http://www.viscoanalyser.com/page8.html
It also has a volume correction factor but be careful how you use that.
Or am I missing something?
JMW
www.ViscoAnalyser.com
RE: Volume correction due to temperature rise?
As already stated above by others, your approach will work pretty good.
Maybe this handy spreadsheet could help with tabulated values of lubricants density vs temperature
w
RE: Volume correction due to temperature rise?
RE: Volume correction due to temperature rise?
There is an issue in timing for measuring the oil loss. I.e. it takes a finite time, possibly many minutes, for the oil to drain back from galleries/heads into the sump before a volume measurement would stabilize. The same issue presents for filling the engine, i.e. how fully drained was it before being filled, were dead spots that don't drain back (e.g. oil filter) already prefilled with oil. Perhaps that is an issue that on a production line would be overcome by establishing a baseline measurement for a known "good" engine, provided the procedure is well controlled, and the drain-back time is not allowed to vary enough to scatter the measurement.
Weighing the engine would seem to be a good alternative. There might be issues if some components off-gas or "burn in" and lose significant weight in the process.
Would oil loss not show up in exhaust diagnostics?