Converting % Dissolved oxygen to mg/L

Does anyone know how to convert % dissolved oxygen to milligrams per liter?

[JohnS]

There are tables or formulas that express the maximum (saturated) O2 as a function of temperature, pressure, and salinity in mg/L. Detrmine saturated value, then multiply by the given percentage.

This Wikipedia article is a place to start (skip over the blood section), The formula for water considers salinity and temperature, but not pressure. Follow the link to the USGS site for a pdf document with tables. They include pressure. http://en.wikipedia.org/wiki/Oxygen_saturation

Much like water vapor in air for humidity calculations, it is not a trivial conversion

[JohnS]

Here is an "official" (web copy) of the USGS memo on calculating this. http://water.usgs.gov/admin/memo/QW/qw81.11.html
It is the only method accepted for USGS work. It contains typos probably related to conversion to the web. (missing minus signs, superscripts, etc)

This document is a "readme" for an Excel spreadsheet that implements the method. The author mentions the typos above and formula corrections he made (see Table 1) to get results in agreement with USGS tables. http://science.nature.nps.gov/im/uni...tor_Readme.doc

I think between the two, you can duplicate the math.