DOTABLES

Dissolved oxygen solubility tables

Information

DOTABLES is an on-line program that generates tables of dissolved oxygen (DO) solubility values and (or) salinity correction factors over a range of user-specified values for water temperature, barometric pressure, and salinity or specific conductance. In addition to generating tables, DOTABLES can compute a single-value of oxygen solubility and percent saturation for a specific instance of temperature, pressure, and salinity.

Version 3.6 -- 2018/08/27 [version history]
Note that version 3.0 [2011/08/03] was a major upgrade in which the equations used to compute oxygen solubility were replaced by equations developed by Benson and Krause (1980, 1984). Documentation and explanation of the revised methods used by DOTABLES can be found in USGS Office of Water Quality Technical Memorandum 2011.03

Software

DOTABLES is executed from this page by choosing the type of desired result (single-value computation, DO solubility table, or salinity correction factor table), providing the required inputs, and then clicking the "Submit" or "Make Table" button from the appropriate section below. The equations used to make these computations are valid for the following ranges:

	Water temperature:	0-40 degrees Celsius or 32-104 degrees Fahrenheit
	Barometric pressure:	380-836 mm Hg, 14.97-32.91 in Hg, 507-1114 mbar, 51-112 kPa, or 0.5-1.1 atm
	Salinity or SC:	0-40 ‰ salinity, or 0-59118 µS/cm specific conductance

Note: Javascript is not currently enabled in your browser for this page. While DOTABLES will still work without javascript, enabling javascript for this page will greatly help to clarify and simplify data input, enable some error checking, and speed up the single-value computation.

A.— Single-Value Computation

To compute a single value of oxygen solubility and percent saturation, fill out the form below and click the "Submit" button. You may choose to input water temperature and barometric pressure in a variety of units. Similarly, you may choose to enter a value for either specific conductance (in µS/cm) or salinity (in ‰). Results are shown to the right. Assuming that javascript is enabled, the result is computed without leaving this page, and changing any input value will erase the result until the "Submit" button is clicked. Percent saturation is computed as the user-specified DO measurement divided by the solubility, expressed as a percentage.

Inputs:		Results:
Water temperature:		Oxygen solubility:	mg/L
Barometric pressure:		Percent saturation:	percent
	µS/cm (SC) or ‰ (salinity)
[optional] Measured DO:	mg/L

B.— Oxygen Solubility Tables

In this section, tables of the solubility of oxygen in water can be computed for a range of water temperatures and barometric pressures at a single value for salinity or specific conductance. Simply enter the desired minimum and maximum values for temperature and pressure along with an increment for each in the form below. To use the salinity correction factor tables of the next section, specify fresh water by choosing a salinity or specific conductance of zero.

For your convenience, input values for temperature and pressure may be entered in a variety of units. The units you choose will be used to generate the solubility tables. If javascript is enabled in your browser for this page, an additional checkbox becomes visible which allows you to choose whether you wish to have the page convert the input values upon selection of a new unit system.

Finally, choose the desired precision of the values in the output table, select an output format, and click the "Make Table" button. If you wish to import the results into a spreadsheet, the CSV or comma-separated text file is a good option.

Step 1:

Choose a range of values for water temperature, barometric pressure, and salinity:

Water temperature:			Barometric pressure:
Units:			Units:
Minimum:			Minimum:
Increment:			Increment:
Maximum:			Maximum:

Salinity or specific conductance:
Input type:
Single value:	(0 = fresh water)
To use the solubility table with a salinity correction factor (below), specify a salinity or specific conductance of zero.

Step 2:

Select the precision of the output:

Dissolved oxygen solubility values to the nearest 0.1 mg/L
Dissolved oxygen solubility values to the nearest 0.01 mg/L

Step 3:

Choose the type of output format for the table.

Step 4:

Make the table, or reset the form and try again.

C.— Salinity Correction Factor Tables

The salinity correction factor is the ratio of the solubility of oxygen in water at a particular salinity to its solubility in fresh water at an identically specified water temperature and barometric pressure. These factors can be useful for the calibration of some DO probes and as a useful pairing to fresh-water tables of oxygen solubility as a function of temperature and pressure.

In this section, tables of salinity correction factors can be computed for a range of water temperature and salinity or specific conductance values. Simply enter the desired minimum and maximum values for temperature and salinity (or specific conductance) along with an increment for each in the form below.

For your convenience, input values for water temperature may be entered in degrees Celsius (°C) or degrees Fahrenheit (°F). Similarly, salinity can be entered directly in per mil units (‰, or parts per thousand), or as specific conductance in microSiemens per centimeter (µS/cm). If specifying specific conductance, the salinity is estimated according to a formula documented in Office of Water Quality Technical Memorandum 2011.03. Whatever units you choose will be used to generate the salinity factor correction tables. If javascript is enabled in your browser for this page, an additional checkbox becomes visible which allows you to choose whether you wish to have the page convert the input values upon selection of a new unit system.

Step 1:

Choose a range of values for water temperature and salinity or specific conductance:

Water temperature:			Salinity or specific conductance:
Units:			Input type:
Minimum:			Minimum:
Increment:			Increment:
Maximum:			Maximum:

Step 2:

Select the precision of the output:

Salinity correction factors to the nearest 0.001
Salinity correction factors to the nearest 0.0001

Step 3:

Choose the type of output format for the table.

Step 4:

Make the table, or reset the form and try again.

Documentation

The methods used by USGS to compute the solubility of oxygen in water as a function of water temperature, barometric pressure, and salinity are documented in Office of Water Quality Technical Memorandum 2011.03:

U.S. Geological Survey, 2011, Change to solubility equations for oxygen in water: Office of Water Quality Technical Memorandum 2011.03, accessed July 15, 2011, at /admin/memo/QW/qw11.03.pdf.

Those methods rely on the research of Benson and Krause as published in the following two papers:

Benson, B.B., and Daniel Krause, Jr, 1980, The concentration and isotopic fractionation of gases dissolved in freshwater in equilibrium with the atmosphere. 1. Oxygen: Limnology and Oceanography, vol. 25, no. 4, p. 662-671. (Also available at https://www.jstor.org/stable/pdfplus/2835754.pdf.)

Benson, B.B., and Daniel Krause, Jr, 1984, The concentration and isotopic fractionation of oxygen dissolved in freshwater and seawater in equilibrium with the atmosphere: Limnology and Oceanography, vol. 29, no. 3, p. 620-632. (Also available at https://www.jstor.org/stable/pdfplus/2836308.pdf.)

USGS methods for determining dissolved oxygen concentrations in water are documented in the USGS National Field Manual:

Radtke, D.B., White, A.F., Davis, J.V., and Wilde, F.D., 1998, National field manual for the collection of water-quality data--dissolved oxygen: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chap. A6, sect. 6.2 [variously paged]. (Also available at /owq/FieldManual/Chapter6/6.2_contents.html.)

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