Overview
IEC 60904-2:2015 - Photovoltaic devices Part 2: Requirements for photovoltaic reference devices - defines requirements for the classification, selection, packaging, marking, calibration and care of devices used as reference standards when measuring the electrical performance of photovoltaic (PV) cells, modules and arrays. The standard applies to reference devices used under natural and simulated sunlight (not for concentrated sunlight) and establishes practices that ensure calibration traceability and reproducible irradiance measurements.
Notable updates in the 2015 edition:
- Addition of a test procedure in simulated sunlight for subsequent measurement of primary and secondary reference devices.
- Definition of standard test conditions.
- Reduction of allowed diffuse component for secondary reference cell calibration (to 20%).
Key Topics and Requirements
- Classification of reference devices: definitions for primary, secondary and working reference devices and guidance on when to use each.
- Selection and construction: single reference cells, encapsulated reference cells, multi-cell reference devices and recommended mechanical/optical features to match test specimens.
- Calibration procedures: traceability chains (primary → secondary → working), calibration under natural sunlight and simulated sunlight, and procedures for calibrating secondary devices against primary cells.
- Environmental and measurement controls: temperature measurement, equivalent cell temperature (ECT) considerations, and requirements for electrical connections.
- Packaging, marking and care: recommended packaging for outdoor and simulator use, marking and data-sheet/report content to preserve calibration integrity.
- Specific test requirements: standard test conditions and limits on diffuse irradiance components when calibrating secondary reference cells.
Practical Applications and Who Uses This Standard
IEC 60904-2:2015 is essential for organizations that require reliable, traceable irradiance measurements and PV performance testing:
- Calibration and metrology laboratories establishing traceability to SI units.
- PV test laboratories performing I–V characterization of cells, modules and arrays.
- Solar simulator manufacturers and users who must match simulator output to reference devices.
- PV module and component manufacturers validating product performance and quality control.
- Certification bodies and research institutions conducting inter-lab comparisons or long-term monitoring.
Using IEC 60904-2 helps ensure measurement consistency, reduces spectral and geometric mismatch risks, and improves comparability of PV performance data across laboratories and field sites.
Related Standards
Key related standards referenced in IEC 60904-2:2015 include:
- IEC 60904-1, -3, -4, -5, -7, -8, -9, -10 (photovoltaic measurements and calibration)
- IEC 60891 (temperature and irradiance corrections)
- IEC 61215, IEC 61646 (module qualification)
- IEC TS 61836 (terms and symbols)
Keywords: IEC 60904-2:2015, photovoltaic reference devices, reference cells, calibration traceability, solar simulator, standard test conditions.