討論 - mesh的問題

涼子迷 · 2008-04-15, 10:09 AM

mesh是指單位面積中有的孔數~我看到都是正數
今天有人問我什麼怎麼會有負數的~

例如-200mesh

這到底是什麼意思阿?????
mesh數越大不就代表孔目越小~
那負數是什麼意思?????

希望知道的大大幫我解答一下喔~
多謝了~

shengweb · 2008-04-15, 10:57 AM

引用:

作者: 涼子迷

mesh是指單位面積中有的孔數~我看到都是正數
今天有人問我什麼怎麼會有負數的~

例如-200mesh

這到底是什麼意思阿?????
mesh數越大不就代表孔目越小~
那負數是什麼意思?????

希望知道的大大幫我解答一下喔~
多謝了~

會不會是200-mesh才對......

涼子迷 · 2008-04-15, 12:23 PM

引用:

作者: shengweb

會不會是200-mesh才對......

我不是很清楚耶~他只告訴我負的~
這是什麼意思阿?請賜教了~

dddd · 2008-04-15, 01:10 PM

http://en.wikipedia.org/wiki/Mesh_(scale)

Particle size distribution
Powders and granular materials are sometimes described as having a certain mesh size (e.g. 30 mesh sand). By itself, this type of description is somewhat ambiguous. More precise specifications will indicate that a material will pass through some specific mesh (that is, have a maximum size; larger pieces won't fit through this mesh) but will be retained by some specific tighter mesh (that is, a minimum size; pieces smaller than this will have passed through the mesh). This type of description establishes a range of particle sizes.

One notation for indicating particle size distribution using mesh size is to use + and - designations. A "+" before the sieve mesh indicates the particles are retained by the sieve, while a "-" before the sieve mesh indicates the particles pass through the sieve. This means that typically 90% or more of the particles will have mesh sizes between the two values.

For instance, if the particle size of a material is described as -80/+170 (or could also be written -80 +170), then 90% or more of the material will pass through an 80 mesh sieve and be retained by a 170 mesh sieve. Using the conversion chart below, the resulting particles will have a range of diameters between 0.089 and 0.178 mm (89 and 178 micrometers).

anotherlevel · 2008-04-15, 01:29 PM

連重點都幫忙畫出來了

謝謝校長啊

taten · 2008-04-15, 04:18 PM

引用:

作者: 涼子迷

mesh是指單位面積中有的孔數~我看到都是正數
今天有人問我什麼怎麼會有負數的~

例如-200mesh

這到底是什麼意思阿?????
mesh數越大不就代表孔目越小~
那負數是什麼意思?????

希望知道的大大幫我解答一下喔~
多謝了~

200目=75um

這個是篩網篩孔的網目數，
數字越大，代表粒徑越小

2目=8000um
10目=1700um
100目=150um
300目=48um
1000目=13um
10000目=1.3um

感謝dddd大的資料提供，"-"代表通過篩網。

atie · 2008-04-15, 09:35 PM

阿逗仔字　偶都看不懂

偶還真速厲害啊

2008-04-15, 10:09 AM	#1
涼子迷長老會員榮譽勳章勳章總數7 UID - 17149 在線等級: 註冊日期: 2002-12-24 住址: 新店安坑文章: 1618 精華: 0 現金: 0 金幣資產: 215960061 金幣	討論 - mesh的問題 mesh是指單位面積中有的孔數~我看到都是正數今天有人問我什麼怎麼會有負數的~ 例如-200mesh 這到底是什麼意思阿????? mesh數越大不就代表孔目越小~ 那負數是什麼意思????? 希望知道的大大幫我解答一下喔~ 多謝了~
	__________________ 青春時我是盲目的射手自負有千萬隻箭就無的放矢自以為豪放終於射盡了囊中之箭梁雲坡射手
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2008-04-15, 01:10 PM	#4 (permalink)
dddd 長老會員榮譽勳章勳章總數13 UID - 42 在線等級: 註冊日期: 2002-12-06 文章: 8621 精華: 0 現金: 89950 金幣資產: 16064755 金幣	http://en.wikipedia.org/wiki/Mesh_(scale) Particle size distribution Powders and granular materials are sometimes described as having a certain mesh size (e.g. 30 mesh sand). By itself, this type of description is somewhat ambiguous. More precise specifications will indicate that a material will pass through some specific mesh (that is, have a maximum size; larger pieces won't fit through this mesh) but will be retained by some specific tighter mesh (that is, a minimum size; pieces smaller than this will have passed through the mesh). This type of description establishes a range of particle sizes. One notation for indicating particle size distribution using mesh size is to use + and - designations. A "+" before the sieve mesh indicates the particles are retained by the sieve, while a "-" before the sieve mesh indicates the particles pass through the sieve. This means that typically 90% or more of the particles will have mesh sizes between the two values. For instance, if the particle size of a material is described as -80/+170 (or could also be written -80 +170), then 90% or more of the material will pass through an 80 mesh sieve and be retained by a 170 mesh sieve. Using the conversion chart below, the resulting particles will have a range of diameters between 0.089 and 0.178 mm (89 and 178 micrometers).

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2008-04-15, 01:29 PM	#5 (permalink)
anotherlevel 長老會員榮譽勳章勳章總數15 UID - 50403 在線等級: 註冊日期: 2003-03-20 住址: 充滿讚美感恩的虎爛宮文章: 14362 精華: 0 現金: 7968 金幣資產: 1353874 金幣	連重點都幫忙畫出來了謝謝校長啊

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2008-04-15, 09:35 PM	#7 (permalink)
atie 超級版主榮譽勳章勳章總數25 UID - 7036 在線等級: 註冊日期: 2002-12-08 住址: 面壁思過協會文章: 18159 精華: 0 現金: 101 金幣資產: 134807277 金幣	阿逗仔字　偶都看不懂偶還真速厲害啊
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