The unit is very helpful for an initial evaluation, is therefore quite recommendable, but one must know the result of interpreting. For example, the salt content in the masonry or flush lines of metal direct influence on the measurement result. Ultimately, can bring only an approximate estimate of the moisture condition this measurement manner, even if the results are reproducible at the same locations. The results are therefore not absolutely to evaluate. In order to certainly determine the water content in the masonry, one would have to weigh a stone of this wall, dry in the oven and then weigh again. However, since this is not so simple in practice, this device offers a very good orientation.