Disscussing old, rare, very specific or otherwise uncommon units and measurements
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Fri Oct 21, 2005 1:38 am
Can a concentration in milligrams per cubic meter be converted to parts per million?
Fri Sep 15, 2006 6:11 am
yes, mg/cubic m can be converted into ppm...how is what i'm trying to figure out :)
Fri Sep 15, 2006 7:30 pm
Per cubic meter of what? If you know the weight per cubic meter, you already have the weight of the impurity or whatever, in milligrams. Then you can do ppm by weight.
But, like all ppm, do you need it calculated as a weight ratio, volume ratio, or mole fraction. Ppm is deprecated because it is an ambiguous term.
Thu Oct 12, 2006 12:56 am
Tankertlm wrote:Can a concentration in milligrams per cubic meter be converted to parts per million?
yes it can be converted. but u make sure that u r taking cubic meter of air or solvent(e.g water).
Fri Oct 27, 2006 5:40 pm
It is something like
mg/m3 = ppm x (molecular weight/ 24) x (293/gas temp)
Can someone tell me if this is correct and why does it have 24 in there?
I am trying to convert ppm of trichloroethene gas into mg/m3
Does anyone out there know how to do this?
Wed Dec 13, 2006 12:34 am
ppm = (TLV in mg/m3)x(24.45) / (gram molecular weight of substance)
Tue Aug 07, 2007 8:00 pm
shameless3 wrote:ppm = (TLV in mg/m3)x(24.45) / (gram molecular weight of substance)
Does anybody know where the 24.45 comes from? :?
Wed Aug 08, 2007 2:08 am
Guest wrote:shameless3 wrote:ppm = (TLV in mg/m3)x(24.45) / (gram molecular weight of substance)
Does anybody know where the 24.45 comes from? :?
It is the volume (in liters) of 1 mole of ideal gas at 25 degrees C, and standard pressure. So the original ratio has been converted to ppm expressed as a mole fraction, micromoles of substance per mole of air, assuming standard pressureand 25 degree C temperature. It is not a universal truth.
Wed Oct 17, 2007 1:23 am
If you change from m^3 to L you have your concentration in mg/L:
0.001m^3 = 1 L
Then you know that:
1 mg/L = 1ppm
So yes you can
Wed Oct 17, 2007 1:55 am
algyra wrote: Then you know that:
1 mg/L = 1ppm
That is ONLY true for a dilute solution in water, based on 1 L of water having a mass of 1 kg, and this remaining approximately true for dilution solutions in water.
It is far from true in air (off by nearly 1000:1), and not very accurate when the solvent is a liquid other than water (like alocohol)
Thu Nov 13, 2008 6:24 pm
Hi folks!
Does anyone out there know how much a cubic metre of wet English oak weighs? I know 'wet' is ambiguous but perhaps an interpolation or maybe that gets complicated.[/u]
Fri Nov 14, 2008 8:20 am
No1Silverback wrote:Hi folks!
Does anyone out there know how much a cubic metre of wet English oak weighs? I know 'wet' is ambiguous but perhaps an interpolation or maybe that gets complicated.
http://www.woodweb.com/index.html would be a better place to ask this question but you can also try the sites below, although they don't address moisture content:
http://www.engineeringtoolbox.com/weigt-wood-d_821.html
http://www.simetric.co.uk/si_wood.htm
http://www.reade.com/Particle_Briefings/spec_gra2.html
Mon Jul 20, 2009 4:34 pm
Tankertlm wrote:Can a concentration in milligrams per cubic meter be converted to parts per million?
water concentration of 100 mg/m3 in air to be coverted into ppm
Wed Sep 30, 2009 6:55 am
how do you convert 6.2*10^-31 into cubic picometers? PLEASE HELP
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