Equivalent performances were observed for SPAD and atLEAF values in different environments regardless of crop species. Therefore, the atLEAF Chl meter can be used as an inexpensive alternative to the SPAD-502 meter. Zhu, J., Tremblay, N. and Liang, Y. 2012.
We found that the relative chlorophyll readings from the SPAD-502 and atLEAF meters were highly correlated both to one another and to chlorophyll content determined with spectrophotometry. Professor Richard Primack's Lab at Boston University