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Standardisation of “methods for testing” characteristics of pyranometers and pyrheliometers. Main points. Classification standard ISO 9060 Missing: Standard for testing instrument characteristics Problem: confusion (freedom) Problem: solar energy industry!! Solution: Maintenance.
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Standardisation of “methods for testing” characteristics of pyranometers and pyrheliometers
Main points • Classification standard ISO 9060 • Missing: Standard for testing instrument characteristics • Problem: confusion (freedom) • Problem: solar energy industry!! • Solution: Maintenance
Conclusion • List of points of attention • Indoor & “worst case” testing • Reactivation of ISO TC180 • Volunteers
Myself • Kees VAN DEN BOS • Engineer Physics • Director / owner Hukseflux Thermal Sensors • Last 20 years sensor design
Founded 1993 Thermal sensors 15 employees 5 radiometry compensation pyrheliometer Hukseflux SR11 pyranometer
Background • Error function of: • Characterisation / class • Calibration • Measurement & maintenance conditions • Environmental conditions
Background • Consultation of manufacturers • Consultation of ISO TC180 • New “testing” (of characteristics) standard • Revision of ISO 9060
New testing standard • Based on indoor experiments • Connection with ISO 98-3 GUM: • “Worst case” as found in real outdoor conditions • Under non-ventilated conditions for non-ventilated instruments (heated conditions for heated instruments etc)
Revision ISO 9060 • Reference conditions: • Horizontal • 500 W/m2 • Normal Incidence • 20 degrees C
Revision ISO 9060 • Zero-offset A (larger!!, ventilated/ heated) • Non-Linearity (horizontal) • Sprectral selectivity (larger!!) • Directional error (separation from non-linearity)
Revision ISO 9060 • Requirements for secondary standard • Now: comply on all specifications • Future: Non-linearity, tilt response, spectral by group compliance • Future: Non-Stability: not included
Miscellaneous • WMO mistake: confuses characterisation and errors due to calibration & conditions • WMO mistake: enters resolution • Ignore WMO? • Maintenance of ISO standards covering calibration.
Conclusion • List of points of attention (new standard + ISO9060) • Indoor & “worst case” testing (GUM / ventilation) • Reactivation of ISO TC180 • Volunteers
P. S. • Memo available via server • Possible cooperation with EU sponsoring