For accurate long-term performance testing of PV modules in outdoor operation, CalLab PV Modules is offering a newly developed data acquisition system. The measurement system has a modular structure and records high-resolution DC measurement data (IV curves) of individual modules. This allows laboratory measurements to be verified and complements comprehensive characterization of modules with respect to the yield properties for new types of technology like bifacial modules. CalLab PV Modules offers this new service throughout the world. The data analysis by Fraunhofer ISE can be adapted according to the client’s requirements, so that all relevant parameters are available with the highest accuracy to our clients.