DIGITS 2.0 : How should I use the "test" data base?

Hi, I’m using the digits-2.0 on ubuntu 14.04LTS.

I’ve created three image database(train/val/test) in the “Datasets”.
Next, I’ve classification using the three databases in the “Models”.

However, in the classification, the “train DB” is used to learning, the “val DB” is used in the evaluation, the “test DB” is not used in the evaluation.

How should I use the “test DB”?
Can I evaluate the “test DB” using the model that has been learned?