IEC 60904-4 pdf download Photovoltaic devices – Part 4: Reference solar devices – Procedures for establishing calibration traceability
This part of lEC 60904 sets the requirements for calibration procedures intended to establishthe traceability of photovoltaic reference solar devices to Sl units as required by lEC 60904-2.
This standard applies to photovoltaic(PV) reference solar devices that are used to measurethe irradiance of natural or simulated sunlight for the purpose of quantifying the performanceof PV devices.The use of a PV reference solar device is required in the application of lEC 60904-1 and lEC 60904-3.
This standard has been written with single junction PV reference solar devices in mind, inparticular crystalline Silicon. However, the main part of the standard is sufficiently general toinclude other technologies. The methods described in Annex A, however, are limited to singlejunction technologies.
The following referenced documents are indispensable for the application of this document.For dated references, only the edition cited applies.For undated references, the latest editionof the referenced document (including any amendments) applies.
IEC 60904-2,Photovoltaic devices – Part 2: Requirements for reference solar devices
ISOIEC 17025,General requirements for the competence of testing and calibrationlaboratories
ISO 9059,Solar energy- Calibration of field pyrheliometers by comparison to a referencepyrheliometer
ISO 9846,Solar energy- Calibration of a pyranometer using a pyrheliometer
ISO/IEC Guide 98-3:2008, Uncertainty of measurement- Part 3: Guide to the expression ofuncertainty in measurement (GUM: 1995)
Terms and definitions
For the purposes of this document, the following terms and definitions apply.
NOTE The different reference instruments for the traceability chain of solar irradiance are defined in this Clause.Table 1 lists and compares them with those in use for time. Figure 1 shows schematically the most commontraceability chains, based on the methods described in Annex A.
a device, which implements physically one of the Sl units or directly related quantities.Theyare usually maintained by national metrology institutes (NMIls) or similar organisations
entrusted with maintenance of standards for physical quantities.Often referred to also just asthe uprimarys, the physical implementation is selected such that long-term stability, precision and repeatability of measurement of the quantity it represents are guaranteed to the maximum extent possible by current technology.
NOTE The World Radiometric Reference (WRR) as realized by the World Standard Group (WSG) of cavity radiometers is the accepted primary standard for the measurement of solar irradiance.