×
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

Why is the hydrometer analysis often designated 'MA'?

Why is the hydrometer analysis often designated 'MA'?

Why is the hydrometer analysis often designated 'MA'?

(OP)
We are having an interoffice debate over the origin of the test request designation of MA for hydrometer analysis.  In our own lab we have SA for sieve analysis, and MA for hydro.  Most think that the M is for mechanical, but that applies to the sieve, too.  How about mass?  Or is the M from the M in ML or MH?  Can anyone offer an answer?

RE: Why is the hydrometer analysis often designated 'MA'?

The M I believe would apply to M in ML or MH. The M stands for silt which is the fraction that the hydrometer grades.

RE: Why is the hydrometer analysis often designated 'MA'?

You guys have a tradition that's all your own.  I've worked in geotechnical firms across the country and MA stands for "mechanical analyses", which is another term for a "sieve".  The hydrometer would not fall into the catigory of mechanical analysis.

f-d

RE: Why is the hydrometer analysis often designated 'MA'?

We call it Mechanical analysis or Sedimentation....the really lazy folk just call it pipette!

RE: Why is the hydrometer analysis often designated 'MA'?

DRC 1, does the hydrometer not measure from coarse sand size down?!

RE: Why is the hydrometer analysis often designated 'MA'?

(OP)
Are we the only ones who call it an MA?  I think among ourselves here we've decided that it must be a quirk of the boss.  We are in agreement that MA does refer to 'Mechanical Analysis', but that Mechanical Analysis is understood to include both the sieve analysis and sedimentation, not just the hydrometer.  I found a statement saying just that in Tschebotarioff's 1951 Soil Mechanics text.

RE: Why is the hydrometer analysis often designated 'MA'?

dirtman 85:
Hydrometer analysis is performed on the fraction below the #200. The hyometer analysis measures the change in density of the slurry over time as particles settle out. Coarse fraction woud settle too quickly to measure accurately.

RE: Why is the hydrometer analysis often designated 'MA'?

DRC1:  I think the ASTM for hydrometer includes the soil fraction below the U.S. Standard 40 sieve.  You are correct that you must use the hydrometer to differentiate below the 200 sieve (unless you happen to be one of those folks that has/uses a 320).

f-d

RE: Why is the hydrometer analysis often designated 'MA'?

You can mechanically sieve down to about 100. To properly sieve at 200, it generally needs to be washed. I have never seen soils sieved below 200, although I have seen smaller sieves. We would do hydrometers on the portion passing the 200, as the grain sieve at that point is a computed quantitiy, not a directly measured quantity.

RE: Why is the hydrometer analysis often designated 'MA'?

We just use M for sieve analysis, H for hydrometer - such as M,H.

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