8.2.2 Wind Direction
This
section provides guidance for the acceptance testing of wind vanes; i.e.,
mechanical wind direction sensors which rely on the force of the wind to
turn a shaft. Guidance for the acceptance testing of remote sensors for the
measurement of wind direction is provided in Section 9.
A
technical acceptance test can verify the relative direction accuracy of the
wind vane by employing either simple fixtures or targets within a room
established by sighting along a 30-60- 90 triangle. There is no acceptance
test for sighting or orientation, unless the manufacturer supplies an
orientation fixture and claims that the sensor is set at the factory to a
particular angle (180 degrees for example) with respect to the fixture.
If
A is
to be calculated from direction output samples, the time constant of the
output to an instantaneous change should be estimated. If the direction
output does not change as fast as a test meter on the output can react, the
time constant is too long.
If
A is
calculated by the system, a receiving test should be devised to check its
performance. The manual for the system should describe tests suitable for
this challenge.
8. QUALITY ASSURANCE AND QUALITY CONTROL
8.1 Instrument Procurement
8.1.1 Wind Speed
8.1.2 Wind Direction
8.1.3 Temperature and Temperature Difference
8.1.4 Dew Point Temperature
8.1.5 Precipitation
8.1.6 Pressure
8.1.7 Radiation
8.2 Installation and Acceptance Testing
8.2.1 Wind Speed
8.2.2 Wind Direction
8.2.3 Temperature and Temperature Difference
8.2.4 Dew Point Temperature
8.2.5 Precipitation
8.2.6 Pressure
8.2.7 Radiation
8.3 Routine Calibrations
8.3.1 Sensor Check
8.3.2 Signal Conditioner and Recorder Check
8.3.3 Calibration Data Logs
8.3.4 Calibration Report
8.3.5 Calibration Schedule/Frequency
8.3.6 Data Correction Based on Calibration Results
8.4 Audits
8.4.1 Audit Schedule and Frequency
8.4.2 Audit Procedure
8.4.3 Corrective Action and Reporting
8.5 Routine and Preventive Maintenance
8.5.1 Standard Operating Procedures
8.5.2 Preventive Maintenance
8.6 Data Validation and Reporting
8.6.1 Preparatory Steps
8.6.2 Levels of Validation
8.6.3 Validation Procedures
8.6.4 Schedule and Reporting
8.7 Recommendations