"Mass fraction" is a well-defined term and, yes, "ppb" isn't in the sense that it doesn't specify what a "part" is.
For names of these types of quantities, I highly recommend section 8.6.2 of <http://www.nist.gov/pml/pubs/sp811/sec08.cfm>. Regards, Steve Emmerson On Thu, Jun 30, 2016 at 11:56 AM, Lowry, Roy K. <[email protected]> wrote: > Dear All, > > > Having read through the SeaOWL specification provided by Mike's link, I > see it is something totally new making a combination of fluorescence and > backscatter measurements at different wavelengths and using the results > in a calibration algorithm to produce measurements of an analyte that > WETLabs/SeaBird describe as 'crude oil'. This is NOT the same thing as TPH > (a wet chemical measurement), although in most environments the two will > be linearly correlated. I therefore now think that it would be best to > use the terminology of the instrument manufacturer: i.e. 'crude_oil'. > > > The mass fraction/mass concentration issue is an interesting one. This > difference has received much attention in the oceanographic research > community with very precise conversions between mass concentrations to mass > fractions depending upon variations in temperature, pressure and salinity. > However, I strongly suspect that the 'ppb' units of the new instrument have > an assumption of pure water density somewhere in the calibration algorithm > and take no account of salt water density variations. In other words 'ppb' > means BOTH unit mass per unit mass and unit mass per unit volume. > > > Having given this some thought, I think Mike's original mass fraction is > probably the better choice as without further information we can only > assume that 'ppb' is dimensionless. So, this gives us: > > > mass_fraction_of_crude_oil_in_sea_water > > > Is this agreeable to all? If so, all we need is some work on the > definition to add what is meant by 'crude_oil' to what Mike has already > provided which just defines 'mass fraction'. > > > Cheers, Roy. > > > Please note that I partially retired on 01/11/2015. I am now only working > 7.5 hours a week and can only guarantee e-mail response on Wednesdays, my > day in the office. All vocabulary queries should be sent to > [email protected]. Please also use this e-mail if your requirement is > urgent. > > > ------------------------------ > *From:* CF-metadata <[email protected]> on behalf of > Jonathan Gregory <[email protected]> > *Sent:* 30 June 2016 17:06 > *To:* [email protected] > *Subject:* Re: [CF-metadata] New standard name for > mass_fraction_of_petroleum_in_sea_water > > Dear Mike > > I agree that petroleum_hydrocarbons is more specific and therefore > preferable. > Is it possible to omit "total", or does it have a specific meaning too and > therefore convey some extra information? It would be good to be explicit if > that is the case. > > Best wishes > > Jonathan > > ----- Forwarded message from [email protected] ----- > > > Date: Thu, 30 Jun 2016 15:57:35 +0000 > > From: [email protected] > > To: "Lowry, Roy K." <[email protected]>, Ute Brönner < > [email protected]>, > > "'[email protected]'" <[email protected]> > > CC: Petter Rønningen <[email protected]>, Jørgen Skancke > > <[email protected]>, Tor Nordam <[email protected]>, CJ > > Beegle-Krause <[email protected]> > > Subject: Re: [CF-metadata] New standard name for > > mass_fraction_of_petroleum_in_sea_water > > > > Dear Ute and Roy, > > Thank you for your careful consideration and deliberation on my > proposal. I would be satisfied by replacing "petroleum" in my original > suggestion with either Ute's suggestion of "contaminant" or Roy's > suggestion of "total_petroleum_hydrocarbons", although I find the latter a > little more specific, particularly if one were to envision a situation in > which intentionally released dispersants were being tracked at the same > time and also categorized as "contaminants". > > As to the question of mass concentration vs. mass fraction, I am trying > to represent the measurements of the SeaOWL UV-A sensor ( > http://wetlabs.com/SeaOWL), which appears to be calibrated in units of > ppm -- and hence mass fraction seems appropriate. The model that will > assimilate these measurements is under active development, and may likely > generate a mass concentration value. So perhaps there ought to be > both mass concentration AND mass fraction standard names. > <http://wetlabs.com/SeaOWL> > SeaOWL UV-A™ (Sea Oil-in-Water™ Locator) | WET Labs > <http://wetlabs.com/SeaOWL> > wetlabs.com > Sea-Bird Scientific introduces SeaOWL UV-ATM, a new in-situ oil-in-water > sensor. Based-upon the highly successful WET Labs ECO sensor, Sea-Bird > Scientific has ... > > > > Thank you,Mike Godin > > #yiv0904837381 #yiv0904837381 -- _filtered #yiv0904837381 > {font-family:Helvetica;panose-1:2 11 6 4 2 2 2 2 2 4;} _filtered > #yiv0904837381 {font-family:Helvetica;panose-1:2 11 6 4 2 2 2 2 2 4;} > _filtered #yiv0904837381 {font-family:Cambria;panose-1:2 4 5 3 5 4 6 3 2 > 4;} _filtered #yiv0904837381 {font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 > 2 4;} _filtered #yiv0904837381 {font-family:Tahoma;panose-1:2 11 6 4 3 5 4 > 4 2 4;} _filtered #yiv0904837381 {panose-1:2 15 3 2 2 2 4 3 2 4;} _filtered > #yiv0904837381 {panose-1:2 0 6 0 0 0 0 0 0 0;} _filtered #yiv0904837381 > {font-family:Webdings;panose-1:5 3 1 2 1 5 9 6 7 3;} _filtered > #yiv0904837381 {font-family:Consolas;panose-1:2 11 6 9 2 2 4 3 2 > 4;}#yiv0904837381 #yiv0904837381 p.yiv0904837381MsoNormal, #yiv0904837381 > li.yiv0904837381MsoNormal, #yiv0904837381 div.yiv0904837381MsoNormal > {margin:0cm;margin-bottom:.0001pt;font-size:12.0pt;}#yiv0904837381 a:link, > #yiv0904837381 span.yiv0904837381MsoHyperlink > {color:#0563C1;text-decoration:underline;}#yiv0904837381 a:visited, > #yiv0904837381 span.yiv0904837381MsoHyperlinkFollowed > {color:#954F72;text-decoration:underline;}#yiv0904837381 pre > {margin:0cm;margin-bottom:.0001pt;font-size:10.0pt;}#yiv0904837381 > p.yiv0904837381MsoAcetate, #yiv0904837381 li.yiv0904837381MsoAcetate, > #yiv0904837381 div.yiv0904837381MsoAcetate > {margin:0cm;margin-bottom:.0001pt;font-size:8.0pt;}#yiv0904837381 > p.yiv0904837381MsoListParagraph, #yiv0904837381 > li.yiv0904837381MsoListParagraph, #yiv0904837381 > div.yiv0904837381MsoListParagraph > {margin-top:0cm;margin-right:0cm;margin-bottom:0cm;margin-left:36.0pt;margin-bottom:.0001pt;font-size:12.0pt;}#yiv0904837381 > span.yiv0904837381HTMLPreformattedChar > {font-family:Consolas;}#yiv0904837381 span.yiv0904837381EmailStyle20 > {color:#1F497D;}#yiv0904837381 span.yiv0904837381EmailStyle21 > {color:windowtext;}#yiv0904837381 span.yiv0904837381BalloonTextChar > {}#yiv0904837381 span.yiv0904837381EmailStyle24 > {color:#1F497D;}#yiv0904837381 .yiv0904837381MsoChpDefault > {font-size:10.0pt;} _filtered #yiv0904837381 {margin:70.85pt 70.85pt > 70.85pt 70.85pt;}#yiv0904837381 div.yiv0904837381WordSection1 > {}#yiv0904837381 > > > _______________________________________________ > > CF-metadata mailing list > > [email protected] > > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > > ----- End forwarded message ----- > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > ------------------------------ > This message (and any attachments) is for the recipient only. NERC is > subject to the Freedom of Information Act 2000 and the contents of this > email and any reply you make may be disclosed by NERC unless it is exempt > from release under the Act. Any material supplied to NERC may be stored in > an electronic records management system. > ------------------------------ > > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > >
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