This is the raw data collected from various experiments seeking to characterize reverse osmosis membrane performance under dynamic feed conditions (i.e., varying feed pressure and flow rate) such as those that might be experienced in a wave desalination system. This data was collected at the National Renewable Energy Lab by Kurby Sitterley, Zach Binger, and Scott Jenne. The included data is from four different experimental types: - Steady-state - Trapezoidal wave form (ramping data) - Sinusoidal wave form - WEC-Sim simulation wave form The data is presented in comma separate value (.csv) format. All the data is presented in its raw form. The data has been clipped from the original data files to exclude data collected during start up or shut down and data collected between experiments. Thus, a user should be able to load the data directly without having to exclude any extraneous data. The README contains additional information on the experimental system, the format of the data (including column headers), and the experimental conditions used for the collected data. Note: The steady-state and ramping data provided here was used for an article titled "Comparing Constant and Transient Membrane Transport Parameters for use in Wave Desalination Models" published in the journal Membranes. Guidance on further processing of this data could be taken from that publication.