VMP Pressure Sensor Accuracy

The profiling velocity, W, of a VMP instrument is derived using the signal dP/dt from the integrated pressure sensor.  It is imperative to have an accurate and high-resolution sensor to derive the rate of change of pressure, because it is used to convert the shear-probe data into physical units, and to convert the time rate […]

Chlorophyll-a values from CLTU-VMP-250 Nose-Mounted Fluorometer/Optical Backscatter Sensor

The VMP-250 features an integrated compound fluorometer and optical backscatter (OBS) sensor to measure chlorophyll and turbidity.  This CLTU-VMP-250 sensor is co-located on the nose of the profiler with the microstructure sensors and designed for RSI for vertical profiling applications.    The CLTU-VMP-250 compound chlorophyll/turbidity sensor uses a light emitting diode for fluorescence and backscattering […]

Vibrations Sensors: History, Signal Output and Calibration with Rockland Instruments

In 2010, 2-axis piezo-accelerometers (vibration sensors) and a precision inclinometer accurate to 0.1 degrees replaced three DC-response accelerometers in Rockland instruments. The new system produces far better low-frequency angle measurements and a much improved signal-to-noise ratio for higher frequencies. The purpose of the vibration sensors is not to quantify the acceleration of a VMP or […]

Rockland Customers Tow-Yow-ing the VMP-250

Rockland Scientific instrument users continue to push the operational boundaries of microstructure turbulence measurements.  A sub-section off these microstructure data collection trailblazers have been developing “tow-yow-ing” techniques with the VMP-250 to gather underway profiles in the mixed layer. 1. Oregon State University Dr. Kipp Shearman, Dr. Johnathan Nash and the Ocean Mixing Group at OSU […]

A Method for Determining Mixing Rates from Concurrent Temperature & Velocity Measurements

Ocean mixing has historically been estimated using Osborn’s model by measuring the rate of dissipation of turbulent kinetic energy and the background density stratification N while assuming a value of the flux Richardson number, Rif. A constant Rif of 0.17 is typically assumed, despite mounting field, laboratory, and modeling evidence that Rif varies. This challenge […]

Corrosion Prevention: Anodes, Nail-polish, and Continuity Checks

Corrosion prevention is an easy to overlook, yet critical practice for operating in the corrosive environment of the ocean. Your Rockland Scientific MicroStructure instrument is equipped with one or more sacrificial anodes to prevent corrosion of your instrument. The anodes are electrically connected to the entire instrument providing protection to the instrument when submerged in […]