Particle Mesh Size units

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Issue migrated from trac ticket # 24

component: help | priority: major | resolution: wontfix | keywords: sieve mesh "particle size"

2009-04-27 05:48:04: Bruce.Simons@dpi.vic.gov.au created the issue

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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?

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2009-07-18 17:17:55: gschadow@pragmaticdata.com

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2009-07-18 17:17:55: gschadow@pragmaticdata.com commented

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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.

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2009-07-20 00:32:19: Bruce.Simons@dpi.vic.gov.au uploaded file mesh sizes.ppt (510.0 KiB)

Table showing various mesh sizes

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2009-07-20 00:36:32: Bruce.Simons@dpi.vic.gov.au commented

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Replying to [comment:1 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.

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2009-07-28 10:04:49: Simon.Cox@csiro.au commented

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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.

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2009-09-25 15:24:03: gschadow@pragmaticdata.com commented

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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.

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2010-04-07 07:18:03: Simon.Cox@csiro.au uploaded file seive.xls (22.5 KiB)

Spreadsheet of seive openings mapped to various seive number designations (taken from the other attachment)

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2010-04-07 07:22:35: Simon.Cox@csiro.au commented

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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.

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2012-10-31 15:41:45: gschadow@pragmaticdata.com commented

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Thank you, Simon, do you move to reject this? It is your area of expertise much more than mine.

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2014-06-18 00:54:50: gschadow@pragmaticdata.com changed status from new to reject_proposed

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2014-06-18 00:54:50: gschadow@pragmaticdata.com edited the issue description

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2021-01-15 04:09:26: simon.cox@csiro.au changed status from reject_proposed to new

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2021-01-15 04:09:26: simon.cox@csiro.au set component to help

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2021-01-15 04:09:43: simon.cox@csiro.au changed status from new to closed

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2021-01-15 04:09:43: simon.cox@csiro.au set resolution to wontfix