When the user wants to use measurements or pre-calculated data, rather than using MERLIN-Expo to calculate it dynamically, the measurement versions of the environmental models can be used to avoid having to enter the same data in many places.
For example: The user wants to calculate the resulting concentrations of different types of crop, given soil concentrations that have been measured. The user thus adds one model for each category of crops. Each category will ask for soil concentrations (in the time series screen). Rather than having to import the same data for each type of crop, the user can add a soil measurements model. This model is a dummy version of soil into which the user can enter the data directly.