×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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!
  • Students Click Here

*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

Jobs

Saybolt Viscosity test

Saybolt Viscosity test

Saybolt Viscosity test

(OP)
I recently tested MC - 70 (Medium curing cutback) using saybolt viscometer. I got a result of efflux time of 50 sec @ 50 oC temp.; while the Specification says 60-120 sec.

Using a conversion table of Furol to kinematic viscosity; the 50 sec is approximately equal to 105 Centistokes and for MC - 70, the required kinematic viscosity is between 70 to 140.

I am now in doubt to accept or reject the material. Any idea please?  

RE: Saybolt Viscosity test

A quick Google turned up a table of kinematic viscosity and equivalent Saybolt 122°F and 212°F numbers (http://www.westerndynamics.com/Download/kinsayfurvisc.pdf) and a Saybolt of 50 at 122°F (50°C) is a little bit above 100 cSt kinematic viscosity - I would assume that this kinematic viscosity is at 50°C.  

Most of the lube oil product literature we receive uses data generated at 40°C and 100°C and for this reason, our viscosity baths are at 40 and 100 degrees.  My question to you is whether the 70-140 range you have is based on 40°C or 50°C (122°F)?  If you didn't adjust for the different temperatures, then you have only the Saybolt data to base your accept/reject call on and you might as well reject the oil.


Did you try running a kinematic viscosity directly?

RE: Saybolt Viscosity test

(OP)
SMF1964, Thank you,

SMF1964, actually I am doing a test on cutback bitumen (I think cutback bitumen is no more in use in USA and other countries). For cutback bitumen we test Saybolt viscosity at 50°C and Kinematic viscosity at 60°C (in our case) or at 135°C. The 70-140 cSt is for kinematic viscosity at 60°C.

Yes, I indeed run a kinematic viscosity test later, for making conclusion, as it is recommended by AASHTO that viscosity indexes be derived from kinematic viscometer than saybolt viscometer. At the time, I asked because I didn’t have the kinematic viscometer in the project site laboratory.

We also modified the MC-70 bitumen to get an efflux time between 60 – 120 sec of the Saybolt viscosity and we got also the right kinematic viscosity.



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!


Resources