### Sea Water - Equation of State Calculator - TEOS-10 & IES-80

The converter uses the latest validated methods (TEOS-10) and the previous one (IES-80) to calculate Salinity, Conductivity and Density. A new way to look at water [1] [2].

#### Notes

- The underlying equations are valid for temperatures from -2 to 35 °C, pressures from 0 to 10,000 dbar, and Practical Salinity from 2 to 42 for TEOS-10 (salinity from 0 to 42 for IES-80)
- (1) 1 Pa = 1 N/m2 = 10-4 dbar = 10-5 bar = 10.197*10-6 at = 9.8692*10-6 atm. Sea level = 0 dbar
- (2) Paris 'point zero' as default. For a reef tank theses values can be kept as default with no significant impact
- (3) Important for the synthetic sea water: algorithms to determine the best estimation for the Absolute Salinity with a non standard composition a not mature enough and will change without any doubt in the future
- (4) Specific Gravity for a pure water [3] at the selected reference temperature (often 20 °C for refractometers)

#### References

- [1] McDougall, T.J. and P.M. Barker, 2011: Getting started with TEOS-10 and the Gibbs Seawater (GSW) Oceanographic Toolbox, 28pp, SCOR/IAPSO WG127, ISBN 978-0-646-55621-5
- [2] Unesco – IES-80 - Algorithms for computation of fundamental properties of seawater – 1983
- Unesco - The International thermodynamic Equation of seawater - 2010 - TEOS-10: a new way to look at water
- ioc.unesco.org - Intergovernmental Oceanographic Commission
- [3] Tanaka M., Girard G., Davis R., Peuto A., Bignell N., "Recommanded table for the density of water between 0 °C and 40 °C based on recent experimental reports", Metrologia, 2001, 38, 301-309

#### Other

Bernard Saulmé - CC - © 2013 - 2021