Updated 2/11/2010

Tide Monitoring Systems

Why choose a non-vented system? Non-vented pressure sensor (FSI) Low maintenance Uses barometric sensor at surface (in surface enclosure) to provide accurate water level readings Vented pressure sensor Requires maintenance to keep vent tube clear - i.e., replace desiccant, check for kinks in cable or obstructions that will affect barometric pressure readings. Why choose a pressure-based system over an acoustic system? Pressure Advantages Easy to install and maintain Typically lower-cost Protected from vandalism Acoustic Advantages Accessible for maintenance No recalibration required Installation above water protects from debris and fouling Pressure Disadvantages Will eventually need recalibration (but pressure calibration is not difficult or costly) Acoustic Disadvantages Temperature variation through air column affects accuracy. Measuring temperature near the sensor can help but does not reflect the temperature throughout the air column. Readings can be affected by wave action/debris/high sediment content Operation may be affected by condensation, freezing or other build-up on sensor Accessible to vandals

Falmouth Scientific, Inc. | 1400 Route 28A | PO Box 315 | Cataumet, MA 02534
Tel: 508 564-7640 | Fax: 508 564-7643 | Email: fsi@falmouth.com