Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Quick way to identify fluid (of 3 possible fluids)

Quick way to identify fluid (of 3 possible fluids)

Quick way to identify fluid (of 3 possible fluids)

Hi, I am looking for some advice on how to determine what fluid is in a container (possibilities are isopropanol, MEK, or mixed xylene). Any measurements taken don't really need to be exact so long as they are able to differentiate between those three fluids.

The idea I came up with is to differentiate between the three by using viscosity, using a Zahn cup viscometer. I know that generally these are used for higher viscosity fluids like paint, but I have found a few manufacturers that do make ones for very low viscosity applications that might work for my purpose (.4 to 2cp).

Alternatively, I do not see any other property that separated the three fluids but could possibly use two tests in conjunction to determine the fluid (eg test freezing point to rule out xylene and then look at refractive index to determine between MEK and isopropanol).

Does anyone else have any suggestions or experience either with these fluids or Zahn cup viscometers?

RE: Quick way to identify fluid (of 3 possible fluids)

Your freezing point test could tell you the difference between all of them with a somewhat sensitive methodology. Boiling point test might be an easier experiment to do, but it would be a bit complicated if you can't lose any amount of the sample. You're sure that it can be only one of the three possibilities?

RE: Quick way to identify fluid (of 3 possible fluids)

They all smell very different from one another. Perhaps you were not taught in chemistry class the proper technique for smelling the contents of bottles. Hold the bottle a foot away from your face and use your hand to gently waft some odor toward your nose.

RE: Quick way to identify fluid (of 3 possible fluids)

Wafting would work, though I always get a second wafter to verify lol

RE: Quick way to identify fluid (of 3 possible fluids)

Mixed xylenes are immiscible with water. Isopropanol is miscible with water, and MEK dissolves to a substantial extent (24%) but is not fully miscible, so you could eliminate the xylenes right quick with an eye dropper and a test tube or jar. The odour of xylenes is quite distinctive too- once you've smelled xylenes you won't mistake it for the other two.

Assuming it's down to MEK or isopropanol, it would be easy to tell them apart by the odour, and fairly easy by the solubility- but a similarly easy way would be to put a few drops on a piece of styrofoam. MEK and xylenes should both dissolve it readily- isopropanol will do nothing, just roll right off.

RE: Quick way to identify fluid (of 3 possible fluids)

Thanks for the great answers everyone. I should have made my original post a little more clear, but I wanted something more objective than smell because an operator will be in charge of testing each container. The Styrofoam and miscibility tests are a great idea and easy to implement.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close