What is the minimum Irradiance level for I-V Curve Tracing?

Opinions vary on this one, but in our experience it’s generally accepted that 700w/m² is used as a base level. I-V curve tracings can be taken at lower levels, but may not be as accurate. As a rule, the higher and more stable the Irradiance the better. If the Irradiance has a possibility of changing during the test (for example shading or changing cloud cover), the I-V curve will reflect this by showing a dip in the curve.