Equilibrium Relative Humidity (ERH)
A hygroscopic material, such as wood or brick, placed in a moist environment (%high RH), absorbs water and its moisture level increases. Inversely, hygroscopic
materials with a high moisture content lose moisture in a dry environment (%low RH).
Moisture migration from a material into the atmosphere and vice versa continues until stabilisation of the vapour pressures of water (inside the material and in the atmosphere). When this equilibrium
is reached, the moisture level of a material can be expressed in Equilibrium Relative Humidity (ERH).
Measuring equilibrium relative humidity allows to establish if a material is dry, limit or damp. For example, when the equilibrium relative humidity of a concrete floor reaches 75%, the contractor
knows that the floor is dry enough to install the floor covering.
Measuring equilibrium relative humidity on site can be done with Humitest Hygro LC thermo-hygrometers or the Humitest MMS with sleeves.
Products
Humidity sleeves for Hygrostick (*20)
Once inserted into substrates, the sleeves (43 mm long, Ø16 mm) create air pockets. Inserting a Hygrostick humidity probe in each sleeve allows to measure Equilibrium Relative Humidity (ERH) of floors.
Humitest Hygro LC (30-100)
With its detachable humidity probe, its lead and sleeves, the Humitest Hygro LC 30-100 thermo-hygrometer allows to measure Equilibrium Relative Humidity of substrates before laying floor coverings or applying paintings or resins.
Humitest MMS
This moisture meter and thermo-hygrometer allows to measure humidity, ambient temperature, dew point and thermal bridges as well as the moisture
content of materials (on the surface and in depth).