The λ90/90 value is the basis for determination of the declared value of the thermal conductivity within the realm of CE declarations of building materials. It is calculated from a measurement series of at least 10 measurements and states which thermal conductivity values to a probability of 90%, can be achieved for 90% of the output production volume. The integrated report calculates the  λ90/90 value by a mouse mouse click. The calculation is based on your measurements; no additional documentation and calculation are required.