title: A Differential Pressure Instrument with Wireless Telemetry for In-Situ Measurement of Fluid Flow across Sediment-Water Boundaries.
abstract: An instrument has been built to carry out continuous in-situ measurement of small differences in water pressure, conductivity and temperature, in natural surface water and groundwater systems. A low-cost data telemetry system provides data on shore in real time if desired. The immediate purpose of measurements by this device is to continuously infer fluxes of water across the sediment-water interface in a complex estuarine system; however, direct application to assessment of sediment-water fluxes in rivers, lakes, and other systems is also possible. Key objectives of the design include both low cost, and accuracy of the order of ±0.5 mm H(2)O in measured head difference between the instrument's two pressure ports. These objectives have been met, although a revision to the design of one component was found to be necessary. Deployments of up to nine months, and wireless range in excess of 300 m have been demonstrated.
authors.affiliation: Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, Woods Hole, MA, 02543, USA.
authors.forename: Alan T
authors.initials: AT
authors.lastname: Gardner
authors.forename: Hanan N
authors.initials: HN
authors.lastname: Karam
authors.forename: Ann E
authors.initials: AE
authors.lastname: Mulligan
authors.forename: Charles F
authors.initials: CF
authors.lastname: Harvey
authors.forename: Terence R
authors.initials: TR
authors.lastname: Hammar
authors.forename: Harold F
authors.initials: HF
authors.lastname: Hemond