LaserLiner 123155 Manual De Instrucciones página 11

9 Application notices
– place the conducting contacts completely on the material to be measured, pressing them down evenly
and lightly to achieve good contact
– measured surface should be free of dust and dirt
– keep at least a 5 cm distance from metal objects
– metal pipes, electric lines and reinforcing steel can falsify measurement results
– make measurements at several locations on the surface
10 Determining material moisture
Due to the differing constitution and composition of materials, specific application notices are to be follo-
wed for their moisture assessment:
Screed: This device also measures through tiles, linoleum, vinyl and wood but these coverings will
influence the measurements. The resulting value is therefore to be viewed as a relative value to localise
moisture and moisture paths.
Plaster: This device also measures through wallpaper and paint but not through metal (foils). Though
measurements may be influenced by such coverings, the moisture in walls can be readily picked up by dif-
ferences in moisture. This enables conclusions to be drawn with respect to damage to insulation, vapour
barriers or masonry, for example.
Wood: The measurement should be made with the length of the device in parallel with the grain of the
wood. The measured depth in wood is 30 mm maximum but does vary somewhat with differing wood
densities. Measurements made on thin wood boards should, if possible, be made on a stack of these
boards as otherwise the measurement will be too low. Measurements made on installed wooden struc-
tures are influenced by the structural conditions and their chemical treatments (e.g. paints) with various
materials. Thus such measurements should only be viewed relatively. Nevertheless, the differences in moi-
sture distribution are very good for localising moist places as an indication of damage, e.g. in insulation.
Greatest accuracy is reached between 6 % and 30 % material moisture. In very dry wood (< 6 %) irregu-
lar moisture distribution can be detected, in very wet wood (> 30 %) saturation of the wood bres begins.
Material relative moisture reference values, in %, for use with wood:
– Outdoor usage:
– Use in unheated rooms:
– In heated rooms (12 °C ... 21 °C):
– In heated rooms (> 21 °C):
Example: 100% material moisture for 1 kg of wet wood = 500 g water.
12 % ... 19 %
12 % ... 16 %
9 % ... 13 %
6 % ... 10 %
MoistureMaster
11
GB