no instructions beyond the on / off. even in English, there is no table for the interpretation of the result. the results vary greatly depending Besides the depression spikes. So book on wood, for walls are simply a trend in finding that the measure is in abutment (40% rh): it is a moisture but not need the visual apparatus is sufficient. by differentiate against a thermal bridge to a fundamental problem (leaks ...) do not count on it. short an inexpensive gadget that allows me to include notes much higher, but in very limited use.