Exaqua PRO3 allows to perform measurements in 3 different wavelengths: 470 nm, 520 nm and 610 nm, while Exaqua PRO6 in 6 different wavelengths : 430 nm, 470 nm, 520 nm, 560 nm, 610 nm and 650 nm.
With Exaqua PRO3 it is possible to take measurements with all reagent sets available in Exaqua range. More wavelengths available in PRO6 gives the user the ability to perform measurements for potentially more tests (parameters). For example, some of the methods included in H-methods license require the use of additional wavelengths comparing to those available in PRO3. PRO6 also means greater flexibility in creating your own methods based on self-made reference solutions or using third-party reagents.