Moisture Meter (Hygrometer)
Moisture meters are used to measure the percentage of water in a particular substance. This information can be used to determine if the material is ready for use, is unexpectedly wet or dry, or otherwise needs further drying. Wood and paper products are very sensitive to moisture. The physical properties are strongly affected by moisture, and the material will gradually deteriorate after a long stay in the high humidity environment.
Freshly cut lumber from logs can have a moisture content (MC- Moisture Content) of 80% or more, depending on the species. Most wood is dried before use, as wood material shrinks in length and width, and can crack, split, bend or deform as it dries. This is usually done using an oven, but can also use the much slower air drying method. In general, the minimum moisture content that can be obtained in air drying in natural conditions is around 20 percent.
In-oven drying is usually monitored by some type of moisture meter. Moisture meters are used to measure whether the amount of water in the wood is suitable for the intended purpose. Building inspectors and many more, carpenters, woodworkers often need to have moisture meters. For example, wood flooring applicators should verify that the MC of the wood matches the relative humidity in the air of the building. If this step is neglected, a wide variety of problems can occur: cracking, pitting, crowning, buckling, and cracked surfaces.
The problems caused by varying degrees of moisture content in wood go beyond simple shrinkage in the size of wood pieces.
The moisture content reading is used to determine whether the material is suitable for its intended use. The total amount of pull varies by tree species. The difference between radial and tangential contraction also varies from species to species. Trees with low tangential and radial shrinkage, such as teak and mahogany, are less prone to degradation due to changes in moisture content than high ratio woods such as eastern pine and some oak species. Species with both low overall shrinkage and low tangential/radial shrinkage ratio are more stable and respond better to changes in moisture content.
The ideal condition for wood to be used in furniture making, wooden floors, construction or any construction project is equilibrium moisture content (EMC – Equilibrium Moisture Content). EMC means that the wood is in equilibrium with the surrounding relative humidity and therefore does not gain or lose moisture content. In reality, however, it is extremely rare for the environment to keep the relative humidity constant, and some degree of dimensional change can be expected with seasonal changes in relative humidity.
Two basic types of moisture meters are available for typical woodworking operations. Depending on the brand, pin-type meters measure the electrical resistance of the wood substrate, called resistivity, or its mutual conductivity. Water conducts electricity freely; consequently, increased water content is associated with increased conductivity. Pin type meters contain two pin electrodes that are driven perpendicular to the wood fibers and directly measure electrical resistance or conductivity. Each moisture meter brand uses specific calculations and displays the final moisture content as a percentage.
The second type of moisture meter is based on the dielectric properties of wood. The measuring instrument measures by means of electrodes that transmit and receive a signal when contacted with wood. The device, which is brought into contact with the tree, generates a low frequency electrical wave and gives information about the humidity of the tree in percent according to a calculation made by the manufacturer.
Moisture meters can also be used by building industry professionals and moisture damage restoration consultants to accurately determine the moisture content of a wide variety of materials in the built environment, such as drywall or interior plaster.
Moisture Measuring Instruments
NEMO-2 is designed for professional use. Depending on the wood group (softness or hardness of the wood), it can measure the humidity of the wood between 4% and 100% at temperatures between 0-90 °C. This instrument, which can measure the temperature of wood between 0-95 °C, makes the most accurate measurement of wood moisture by entering the wood temperature. Being able to give the average value of 99 measurements allows you to have a general information about the humidity of the stock goods. NEMO-2 can measure concrete moisture as well as wood moisture. With its special bag, it provides the opportunity to keep all its apparatus with it and it can be easily transported to the desired place.