Opened 8 years ago
Last modified 3 years ago
#24 reject_proposed enhancement
Particle Mesh Size units
Reported by: | simonsb | Owned by: | |
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Priority: | major | Milestone: | |
Component: | Keywords: | sieve mesh "particle size" | |
Cc: |
Description (last modified by gschadow)
Much soil sampling and geochemistry data uses particle mesh sieves to sort the sample and catagorises the fraction by the "mesh size" (see eg http://en.wikipedia.org/wiki/Mesh_(scale), http://www.azom.com/details.asp?ArticleID=1417. The UCUM standards at http://aurora.regenstrief.org/~ucum/ucum.html specify a "mesh" value "mesh lineic number [mesh_i][MESH_I][in_i]" but this does not appear to be related.
Is there an appropriate "mesh" unit available in UCUM?
Attachments (2)
Change History (9)
comment:1 follow-up: ↓ 2 Changed 8 years ago by gschadow
comment:2 in reply to: ↑ 1 Changed 8 years ago by simonsb
Replying to gschadow:
This is similar to Gauge scales. Please provide a conversion function and a proposal for a unit symbol, then we could add this. If it's just some ordinal scale, then it would not need a unit.
The only UCUM reference I can find is to gauge of catheters: Charrière, french gauge of catheters Ch [Ch] [CH] no 1 mm/[pi]
I understand from the attached table that the Mesh Size is a different unit of measure.
comment:3 Changed 8 years ago by SimonCox
On further investigation, I believe that Lineic number is correct. It is defined as inverse length - i.e. number per unit length. I think all mesh numbers are a scaled inverse-length, so are a lineic number. It just requires the scale factor to be determined.
comment:4 Changed 8 years ago by gschadow
Could be inverse length or inverse circumference or even more complicated. I have once tried to understand needle gauge numbers but had to give up because I could not find a clear definition. This will go into UCUM almost automatically as soon as someone can research a formula -- however complicated -- that relates these gauges or mesh sizes to a standard unit in some way.
Changed 7 years ago by SimonCox
Spreadsheet of seive openings mapped to various seive number designations (taken from the other attachment)
comment:5 Changed 7 years ago by SimonCox
The attached spreadsheet shows that the seive designations are not a strict Unit of Measure, as the relationship between numbers and opening size cannot be expressed as a formula. The British scale is close - (British seive number) = 15300/opening(expressed in um)
but in general seive numbers are an ordered-nominal scale, nit a unit-of-measure.
comment:6 Changed 5 years ago by gschadow
Thank you, Simon, do you move to reject this? It is your area of expertise much more than mine.
comment:7 Changed 3 years ago by gschadow
- Description modified (diff)
- Status changed from new to reject_proposed
This is similar to Gauge scales. Please provide a conversion function and a proposal for a unit symbol, then we could add this. If it's just some ordinal scale, then it would not need a unit.