Scratches or chips on a dome may affect readings, depending on the instrument and its application and the size, location, and number of scratches or chips.
For diffuse horizontal solar irradiance (DHI) measurements the pyranometer is shaded from the direct sun beam and most small scratches will not affect the readings significantly.
Reflected solar radiation is largely diffuse and small scratches will have little effect on the readings.
Global horizontal solar irradiance (GHI) and tilted global solar irradiance include the direct sun beam. Therefore, scratches or chips located on parts of the pyranometer dome over which direct sunlight passes during the day will affect the measurements.
When dome replacement is required, directional response characterization (DiRC) and solar radiation (SRC) calibrations will be completed.