Calibrations

To correct a calibration, enter the slope and offset applied to the loaded data (e.g. programmed in the data logger) and the desired “instrument” slope and offset. The correction factor is applied for you.

Calibration application logic

General calibrations rules for all minimum, mean and max signal values (for all other than Wind Vanes)

  • If uncalibrated data = 0, calibrated data = 0 NOT the offset.

  • If value after application of slope and offset < 0, calibrated data snaps to 0

  • Slope applied to loaded data = abs (instrument slope / logger slope)

  • Offset applied to loaded data = instrument slope - logger slope

Wind Vane special rules

  • Mean, min, max are 0,360 wrapped

  • WindVane std dev not wrapped (if stddev is >360 the logger or calibrations are likely broken)

StdDev special rules (including wind vane std dev)

  • No offset applied

  • Slope applied = abs (instrument slope / logger slope)

    • Allows user to handle a wind vane which has been wire up back to front with negative slopes

  • Std Dev can-not be > sensor max (checked when loading data)

Calibration merge-multiple

The merge adjacent allows you to merge any alike and adjacent-in-time calibrations for each measurement in the current view.

Pre-calibration cut-offs: minimum / maximum range

The measurement minimum and maximum range, set under sensor properties is applied before the data is calibrated. Uncalibrated data outside of the pre-calibration sensor min / max range will not be visible in the “clean measurements” view or accessible to calculations.

Wind vanes wired backwards

WindFarmer: Analyst can correct wind direction data where the vane has been wired up backwards by entering a logger slope of -1.

Wind direction data beyond 0-360

We handle direction data outside the normal 0-360 degree range, for example turbine nacelle direction data which range from -720 to +720. You will need to modify your sensor pre-calibration min and max values if uncalibrated data fall outside the standard range.