A04_Specifications.docx

Requisition#

US Geological Survey St. Petersburg Coastal and Marine Science Center St Petersburg, FL 33701

I. FUNCTIONAL REQUIREMENTS

The USGS Coastal and Marine Science Center in St. Petersburg Florida requires 5 pressure loggers to be used in coastal hazards studies in nearshore waters. A 20 m depth rating and continuous sampling at a user selected sampling frequency up to 16 Hz is required for measuring mean water levels and resolving one-dimension wave spectra of both low and high frequency waves. The pressure loggers will be deployed mounted on the sea floor for autonomous data collection for up to 6 months. Pressure logger shall be a self-contained with piezoresistive pressure gauge, temperature gauge, clock, battery power, and data storage in one small instrument that is resistant to corrosion from saltwater. The resolution of the pressure gauge needs to be <0.001% of full scale and the accuracy of the pressure gauge needs to be within ±0.05% of full scale. The pressure gauge needs to compensate for temperature variations measured by a temperature gauge included within the instrument housing. Clock drift shall not exceed ±60 seconds/year. Internal data storage shall be provided for a minimum of 240M readings. Data needs to be downloadable via USB-C or WiFi and cross platform (PC, Mac) software needs to be available for downloading data and converting it to common machine-readable formats (ascii text, comma delimited text, and/or netcdf formats). The instrument shall be powered by readily available AA batteries and have a compact size not exceeding 260mm x Ø63.3mm and weight in air not exceeding 960g.