http://www.mdpi.com/journal/sensors/special_issues/wireless-pressure-sensors/ Pressure sensing is one of the most common measurements in fluid dynamics, hydraulics, meteorology, chemical processes and biomedical science. Wireless pressure sensing is becoming attractive because of less wiring, improved signal-to-noise ratio, sensor miniaturization and circuit integration, multi-point sensing and ease of networking. Research articles are solicited for a special issue of Wireless Pressure Sensors journal which will provide a consolidated state-of-the-art in this area. The Special Issue of "Wireless Pressure Sensors” will publish those full research, review and high rated manuscripts addressing the above topic. Submission Sensors (http://www.mdpi.org/sensors/) is a highly rated journal with a 1.573 impact factor in 2007. Sensors is indexed and abstracted very quickly by Chemical Abstracts, Analytical Abstracts, Science Citation Index Expanded, Chemistry Citation Index, Scopus and Google Scholar. All papers should be submitted to sensors@mdpi.org with copy to subraman@fit.edu. To be published continuously until the deadline and papers will be listed together at the special websites. Please visit the instructions for authors at http://www.mdpi.org/sensors/publguid.htm before submitting a paper. Open Access publication fees are 1050 CHF per paper. English correction fees (250 CHF) will be added in certain cases (1300 CHF per paper for those papers that require extensive additional formatting and/or English corrections.). http://www.mdpi.com/1424-8220/9/1/404/ 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 H2O 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. http://www.mdpi.com/1424-8220/9/1/404/ Fri, 09 Jan 2009 00:00:00 CET Sensors 2009-01-09 9 1 Article 404 429 1424-8220 A Differential Pressure Instrument with Wireless Telemetry for In-Situ Measurement of Fluid Flow across Sediment-Water Boundaries 2009-01-09 doi: 10.3390/s90100404 Alan T. Gardner Hanan N. Karam Ann E. Mulligan Charles F. Harvey Terence R. Hammar Harold F. Hemond http://www.mdpi.com/1424-8220/8/12/7596/ In this paper the static pressure field of an annular swirling jet is measured indirectly using stereo-PIV measurements. The pressure field is obtained from numerically solving the Poisson equation, taken into account the axisymmetry of the flow. At the boundaries no assumptions are made and the exact boundary conditions are applied. Since all source terms can be measured using stereo-PIV and the boundary conditions are exact, no assumptions other than axisymmetry had to be made in the calculation of the pressure field. The advantage of this method of indirect pressure measurement is its high spatial resolution compared to the traditional pitot probes. Moreover this method is non-intrusive while the insertion of a pitot tube disturbs the flow. It is shown that the annular swirling flow can be divided into three regimes: a low, an intermediate and a high swirling regime. The pressure field of the low swirling regime is the superposition of the pressure field of the non-swirling jet and a swirl induced pressure field due to the centrifugal forces of the rotating jet. As the swirl increases, the swirl induced pressure field becomes dominant and for the intermediate and high swirling regimes, the simple radial equilibrium equation holds. http://www.mdpi.com/1424-8220/8/12/7596/ Fri, 28 Nov 2008 00:00:00 CET Sensors 2008-11-28 8 12 Article 7596 7608 1424-8220 Planar Pressure Field Determination in the Initial Merging Zone of an Annular Swirling Jet Based on Stereo-PIV Measurements 2008-11-28 doi: 10.3390/s8127596 Maarten Vanierschot Eric Van den Bulck http://www.mdpi.com/1424-8220/8/4/2317/ This paper reports a micromachined capacitive pressure sensor intended for applications that require mechanical robustness. The device is constructed with two micromachined metal plates and an intermediate polymer layer that is soft enough to deform in a target pressure range. The plates are formed of micromachined stainless steel fabricated by batch-compatible micro-electro-discharge machining. A polyurethane roomtemperature- vulcanizing liquid rubber of 38-μm thickness is used as the deformable material. This structure eliminates both the vacuum cavity and the associated lead transfer challenges common to micromachined capacitive pressure sensors. For frequency-based interrogation of the capacitance, passive inductor-capacitor tanks are fabricated by combining the capacitive sensor with an inductive coil. The coil has 40 turns of a 127-μmdiameter copper wire. Wireless sensing is demonstrated in liquid by monitoring the variation in the resonant frequency of the tank via an external coil that is magnetically coupled with the tank. The sensitivity at room temperature is measured to be 23-33 ppm/KPa over a dynamic range of 340 KPa, which is shown to match a theoretical estimation. Temperature dependence of the tank is experimentally evaluated. http://www.mdpi.com/1424-8220/8/4/2317/ Wed, 02 Apr 2008 00:00:00 CEST Sensors 2008-04-02 8 4 Article 2317 2330 1424-8220 A Micromachined Capacitive Pressure Sensor Using a Cavity-Less Structure with Bulk-Metal/Elastomer Layers and Its Wireless Telemetry Application 2008-04-02 doi: 10.3390/s8042317 Kenichi Takahata Yogesh B. Gianchandani