Ascertaining the moisture content material of wooden flooring is crucial to the success of flooring set up, in addition to within the case of post-installation water harm. Moisture testing is carried out through the use of each pin-type and non-destructive (pinless) meters. So, how correct are they?
The last word and most correct take a look at for moisture content material of a fabric corresponding to wooden is the gravimetric or oven-based testing technique, when a pattern of the wooden is taken and weighed earlier than having its moisture eliminated via oven drying, after which weighed once more. The proportion distinction in weight is the proportion moisture content material. High quality non-destructive and pin-type moisture meters can replicate this measurement with both qualitative or quantitative readings, relying on their use and diploma of accuracy and precision. The moisture content material in a wooden pattern is calculated utilizing a moisture meter via the measurement of the adjustments within the wooden pattern’s electrical properties and evaluating them with predefined information from gravimetric testing strategies.
Pin-type meters are resistance meters that measure {the electrical} resistance ranges in wooden. The meter interprets the resistance values right into a moisture content material p.c measurement primarily based on the corresponding empirical information outcomes of gravimetric testing.
Non-destructive meters use capacitance to measure the moisture content material of the wooden pattern. A low frequency digital sign is transmitted into the fabric through the electrodes within the base of the instrument. The meter determines the energy of the present and converts this to a moisture content material worth, once more utilizing gravimetric testing as a baseline.
Pin-type meters take a look at a really exact location in a pattern of wooden, between the 2 pins. High quality pin-type meters due to this fact are usually extra exact than non-destructive meters, which take a look at a a lot bigger pattern dimension. The non-destructive meter pattern dimension is the realm or “footprint” of the electrodes on the again of the meter, which may typically measure at totally different depths.
There are benefits and drawbacks to each strategies, in addition to changes that may be made to each that improve their accuracy.
Pin-type meters are usually much less correct when testing woods with moisture content material values of lower than roughly 7 p.c MC. This is because of the truth that when the wooden is dry and the p.c MC drops under 7 p.c, {the electrical} resistance of the wooden will increase exponentially and the readings can change into much less and fewer significant.
High quality non-destructive meters are higher at studying the moisture content material at these decrease ranges. As well as, they, clearly, have the benefit of not being invasive, so can be utilized to cowl a big space in a brief time period and, after all, with out leaving pin holes.
Non-destructive meter readings typically have been thought-about qualitative. This may be as a result of, within the discipline, they could be used to learn via coatings, varnishes, and paints with out damaging the ground floor, and because of the pattern dimension being bigger and deeper than the pin-type pattern, there’s a potential for the readings to be influenced by a substrate beneath the wooden flooring. The consumer then has wanted to check these readings with quantitative readings utilizing a pin-type meter.
To enhance this non-destructive technique of in-the-field testing of flooring merchandise that already are put in, there have been exceptional developments within the shallow depth characteristic. The shallow depth characteristic significantly reduces and even eliminates the affect of the substrate on the non-destructive moisture content material measurements. This characteristic now could be obtainable in a number of moisture meters at the moment in the marketplace.
Measuring Moisture in Wooden
The moisture content material in a wooden pattern is calculated utilizing a moisture meter via the measurement of the adjustments within the wooden pattern’s electrical properties and evaluating them with predefined information from gravimetric testing strategies.
One other very notable replace to the non-destructive shallow depth characteristic is the flexibility to regulate the readings to consider the SG (Particular Gravity) of the wooden. The good thing about this SG adjustment characteristic is two-fold. First, when testing in non-destructive mode, the SG adjustment could be tailored to the density of the wooden species below take a look at, making the non-destructive take a look at much more correct. Second, if the SG of the wooden just isn’t identified, it’s straightforward to match up the non-destructive meter studying to a high-quality pin meter studying, by merely adjusting the SG till the non-destructive readings match the precise pin readings. This permits the consumer to scan the ground non-destructively utilizing the identical density setting and reaching the identical outcomes as they might with a pin-type meter.
There even have been technological developments in pin-type meters, a few of which now embody preset species menus constructed into the meter to pick out from, in addition to built-in infrared floor thermometers that permit for the meter to make the mandatory corrections to the moisture content material readings relying on the temperature of the wooden.
Historically, previous to the event of the very useful shallow depth and SG and temperature adjustment options, the meters would give readings primarily based on a wooden normal (for instance the U.S. forestry Douglas Fir normal) calibrated at a sure temperature and with a sure SG. The consumer then would want to discuss with totally different charts, corresponding to temperature correction charts, wooden species correction charts, or SG adjustment tables.
For added details about moisture meters, take a look at the NWFA’s Set up Pointers at nwfa.org/technical-guidelines/.
Using wooden normal settings, with none changes made, could also be all of the adjustment that’s wanted. There additionally could also be some added worth delivered to the accuracy by adjusting for species and temperature when, for instance, drying water-damaged wooden in order to keep away from overdying, or when working in additional excessive circumstances.
Having that possibility is vital, and so with sure meters, now the consumer can select to check with both a conventional wooden normal with out adjustment, or to activate the superior settings and avail of the built-in adjustment options as wanted, thus permitting the consumer to see each the wooden and the bushes.
Ronan Carrigy is the advertising supervisor for Tramex Moisture Meters in Kilmacanogue,
Eire. He could be reached at ronan@tramexmeters.com. For extra info, go to
tramexmeters.com.
