A magnetic float densimeter for the measurement of changes in water density on aeration

Bignell, N

doi:10.1088/0022-3735/15/3/031

Cited by 19 publications

(10 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For water, the effect of air solubility on density has been measured directly, e.g. by Bignell (1983), by comparing the densities of saturated and desaturated water.…”

Section: Air Saturationmentioning

confidence: 99%

See 1 more Smart Citation

The density–salinity relation of standard seawater

et al. 2018

View full text Add to dashboard Cite

Abstract. The determination of salinity by means of electrical conductivity relies on stable salt proportions in the North Atlantic Ocean, because standard seawater, which is required for salinometer calibration, is produced from water of the North Atlantic. To verify the long-term stability of the standard seawater composition, it was proposed to perform measurements of the standard seawater density. Since the density is sensitive to all salt components, a density measurement can detect any change in the composition. A conversion of the density values to salinity can be performed by means of a density-salinity relation. To use such a relation with a target uncertainty in salinity comparable to that in salinity obtained from conductivity measurements, a density measurement with an uncertainty of 2 g m −3 is mandatory. We present a new density-salinity relation based on such accurate density measurements. The substitution measurement method used is described and density corrections for uniform isotopic and chemical compositions are reported. The comparison of densities calculated using the new relation with those calculated using the present reference equations of state TEOS-10 suggests that the density accuracy of TEOS-10 (as well as that of EOS-80) has been overestimated, as the accuracy of some of its underlying density measurements had been overestimated. The new density-salinity relation may be used to verify the stable composition of standard seawater by means of routine density measurements.

show abstract

“…For water, the effect of air solubility on density has been measured directly, e.g. by Bignell (1983), by comparing the densities of saturated and desaturated water.…”

Section: Air Saturationmentioning

confidence: 99%

“…that of Bignell (1982), use position sensing systems with accuracies that are at least in the micrometre range to keep the height, z, constant. The actual cause of the significance of the density deviations seen in Fig.…”

Section: Atmospheric Pressurementioning

confidence: 99%

The density–salinity relation of standard seawater

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Bignell [5] improved this method in order to measure the changes in the water density due to aeration. He achieved a floating condition by controlling the magnet current in such a way that the float stayed at a defined position.…”

Section: The Magnetic Flotation Methodsmentioning

confidence: 99%

Water density measurement by a magnetic flotation apparatus

Wolf¹,

Bettin²,

Gluschko³

2006

Meas. Sci. Technol.

View full text Add to dashboard Cite

A magnetic flotation apparatus for determining the density of water over a wide temperature range is described. After a short discussion of the advantages of a magnetic flotation method against the hydrostatic weighing method, the apparatus built at the Physikalisch-Technische Bundesanstalt (PTB) is described in detail. Contributions to the measurement uncertainty are discussed. The functionality of the apparatus is demonstrated with a series of water density measurements at 20 °C.

show abstract

“…The high sensitivity of the measurement density to the magnet height position is one reason why magnetic flotation densimeters that were developed later and that share a similar principle, e.g. that of Bignell (1982), use position sensing systems with accuracies that are at least in the micrometre range to keep the height, z, constant. The actual cause of the significance of the density deviations seen in Fig.…”

Section: Atmospheric Pressurementioning

confidence: 99%

The density–salinity relation of standard seawater

Schmidt¹,

Seitz²,

Hassel³

et al. 2017

Preprint

View full text Add to dashboard Cite

Abstract. The determination of salinity by means of electrical conductivity relies on a constant salt composition in the North Atlantic Ocean, as standard seawater, which is required for salinometer calibration, is produced therefrom. In order to verify the long-term constant composition of standard seawater, it was proposed to perform density measurements on standard seawater, as the seawater density is sensitive to all salt components. Thus, density measurements can detect any change in the composition of seawater. A conversion of the density values to salinity can be performed by means of a density–salinity relation. To use such a relation with a target uncertainty in salinity comparable to that in salinity obtained from conductivity measurements, a density measurement at an uncertainty level of 2 ppm is mandatory. In this article, a new density–salinity relation is presented based on such accurate density measurements. The underlying substitution measurement method is described, density corrections for uniform isotopic and chemical compositions are reported, and the density–salinity relation is presented. The comparison of densities calculated using the new relation with those calculated using the present reference equation of state TEOS-10 suggests that the density accuracy of TEOS-10 and that of some of its underlying density measurements are overestimated. The new density–salinity relation may be used to verify the constant composition of standard seawater by means of routine density measurements.

show abstract

A magnetic float densimeter for the measurement of changes in water density on aeration

Cited by 19 publications

References 5 publications

The density–salinity relation of standard seawater

The density–salinity relation of standard seawater

Water density measurement by a magnetic flotation apparatus

The density–salinity relation of standard seawater

Contact Info

Product

Resources

About