Moisture Meters for Wood and Building Materials

<body text="#3333FF" bgcolor="#FFFFFF" link="#000000" vlink="#666666" alink="#FF0000" background="../../bckground.jpg"> <h1> <b><font face="Arial,Helvetica"><font color="#FF0000"><font size="+1">MOISTURE METER FOR WOOD AND BUILDING MATERIALS</font></font></font></b></h1> <table WIDTH="100%" > <tr VALIGN=TOP> <td><font face="Arial,Helvetica"><font color="#3333FF">Our successfull series of small measuring instruments can be used everywehre when it is necessary to quickly and reliably determine the moisture content of materials.</font></font> <p><font face="Arial,Helvetica"><font color="#3333FF">For measuring <a href="../ds4a/air_temperature&air_moisture_sensor/lflt_e.html">rel. air humidity, air temperature, dew point</a> or<b> </b><a href="../ds4a/surface_temperature_sensor/wt_e.html">surface temperature</a>, please visit our page <a href="index_ds4a_e.htm" target="Rechts">DS4A</a>.</font></font> <p><b><font face="Arial,Helvetica"><font color="#3333FF">additional information:</font></font></b> <ul> <li> <font face="Arial,Helvetica"><font color="#3333FF"><font size="-1"><a href="#flooring">moisture measuring in floorings</a></font></font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF"><font size="-1"><a href="#capacitive">capacitive measuring method</a></font></font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF"><font size="-1"><a href="#drying_method">drying method</a></font></font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF"><font size="-1"><a href="#cm_method">CM-method</a></font></font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF"><font size="-1"><a href="#cm_method">conductance measuring principle</a></font></font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF"><font size="-1"><a href="#cm_method">for wood moisure: comparing of conductance measuring and capacitive meauring</a></font></font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF"><font size="-1"><a href="#cm_method">indoor climate</a></font></font></font></li> </ul> <font face="Arial,Helvetica"><font color="#3333FF">There are some additional interessting meters which are made for<b> </b><a href="../wood&timber/index_wood.htm" target="Rechts">wood</a> or <a href="../building/index_building.htm" target="Rechts">building materials</a>.</font></font> <p><b><font face="Arial,Helvetica"><font color="#3333FF">Moisture Meters:</font></font></b> <ul> <li> <font face="Arial,Helvetica"><font color="#3333FF"><a href="../ds4a/ds4a_e.html">type DS4A, universal instrument also for air moisture and temperatures</a></font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF"><a href="../ds4a/ds4a_e.html">type H24/10, instrument with analog display</a></font></font></li> </ul> <b><font face="Arial,Helvetica"><font color="#3333FF"><font size="+1"><a href="../ds4a/ds4a_e.html">home</a></font></font></font></b></td> <td><img SRC="../../baustoffe2.jpg" ALT="foto measurement at flooring" BORDER=0 height=303 width=250></td> </tr> <tr VALIGN=TOP> <td> <hr SIZE="1" WIDTH="100%"></td> <td></td> </tr> <tr> <td> <h2> <a NAME="flooring"></a><font face="Arial,Helvetica"><font color="#3333FF"><font size="+1">Moisture Measuring in Floorings</font></font></font></h2> <font face="Arial,Helvetica"><font color="#3333FF">Our capacitive moisture meter are often used for measuring the moisture content in floorings.</font></font> <ul> <li> <font face="Arial,Helvetica"><font color="#3333FF">the meters measures without damaging</font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF">the measuremets are done yery quickly</font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF">it's possible to estimate the moisture value, if the values are to high, a costly exact determination is not necessary.</font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF">it's possible to observe the drying process without damaging </font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF">In one room, it's possible that there are great moisture differences. Therfore a non destructive moisture meter is important to find out critical places for an exact moisture measurement e.g. the drying method.</font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF">The numbers of necessary exact measurements (e.g. with the drying method) is reduced to a minimum.</font></font></li> </ul> <font face="Arial,Helvetica"><font color="#3333FF">The moisture result of our capacitive moisture meter is influenced through changings in the density, different surfaces and different admixtures. Also very important is the changing of the moisture in different depth. Our meters are hold on the surface, the measuring depth is approx. 3 cm. The influence to our meter gets less with higher depth. Our meters are very good instruments for detecting the moisture differences. </font></font> <p><font face="Arial,Helvetica"><font color="#3333FF">Helpfull is to observe the drying process. If the moisture values are constant in spide of  an optimized ventilation, with a high probability it's coming up a balance condition, in his case a comparing exact measurement (e.g. drying method) is ingenious.</font></font> <p><font face="Arial,Helvetica"><font color="#3333FF">For information about an optimised calibrated moisture meter for special building materials, we ask to visit the pages of our partner DNS-Denzel</font></font> <br> </td> <td></td> </tr> <tr> <td> <hr SIZE="1" WIDTH="100%"></td> <td></td> </tr> <tr VALIGN=TOP> <td> <h2> <a NAME="capacitive"></a><b><font face="Arial,Helvetica"><font color="#3333FF"><font size="+1">Capacitive Measuring Method</font></font></font></b></h2> <font face="Arial,Helvetica"><font color="#3333FF">This is the most cost effective measuring principle to measure the moisture without damaging the material. An average value is measured till a depth of approx. 3 cm</font></font> <p><font face="Arial,Helvetica"><font color="#3333FF">The meter are  working in accordance with the principle of an opened plate capacitor. The capacity of the capacitor depends on the material-(dielectric)-constant (DC) of the material in between the plates. Compared with air, for example (DC = 1) water has got a very high dielectric-constant (DC ~ 80). The water content of a wet material can therefore be determined by determining the dielectric constant of this material.</font></font> <p><font face="Arial,Helvetica"><font color="#3333FF">The measurements are influenced through differences in the material densities.</font></font> <br> </td> <td><img SRC="../../instr-alle-prinzip.jpg" BORDER=0 height=224 width=300> <DL> <i><font face="Arial,Helvetica">(1) field lines</font></i></DL> <DL> <i><font face="Arial,Helvetica">(2) material to be measured</font></i></DL> <br><i><font face="Arial,Helvetica">(3) plate capacitor</font></i></td> </tr> <tr> <td> <hr SIZE="1" WIDTH="100%"></td> <td></td> </tr> <tr> <td> <h2> <a NAME="drying_method"></a><b><font face="Arial,Helvetica"><font color="#3333FF"><font size="+1">Drying method</font></font></font></b></h2> <font face="Arial,Helvetica"><font color="#3333FF">The drying method is the most accurate measuring principle. We recommend this measuring principle for all comparing measurements.</font></font> <br><font face="Arial,Helvetica"><font color="#3333FF">For wood moisture there is a German norm DIN 52183 or an international norm ISO 3130-1975</font></font> <br><font face="Arial,Helvetica"><font color="#3333FF">We recommend the following steps:</font></font> <ul> <li> <font face="Arial,Helvetica"><font color="#3333FF">we recommend a balance with a measuring range of 200 g and an accuracy of ±0,01 g</font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF">make non destructive measurements to find out the critical places with the highes moisture value</font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF">take a probe, for wood use a sharp saw, avoid border parts; for building materials use a sharp chissel, take not only surface parts, the depth for taking the probe should be at least 2 cm, the weight should be at least 20 g</font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF">take immediately the exact weight of the probe, name it W1</font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF">put the probe in an temperature regulated oven and dry the probe till the weight is constant.</font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF">the maximum drying temperature for wood: 104°C</font></font></li> <br><font face="Arial,Helvetica"><font color="#3333FF">the maximum drying temperature for cement flooring: 100°C</font></font> <br><font face="Arial,Helvetica"><font color="#3333FF">the maximum drying temperature for anhydride flooring: 40°C</font></font> <li> <font face="Arial,Helvetica"><font color="#3333FF">take the dry weight as W2</font></font></li> <li> <font face="Arial,Helvetica"><font color="#3333FF">calculate the moisture M with the following formula:</font></font></li> <table BORDER WIDTH="80%" > <tr> <td><font face="Arial,Helvetica">for wood:</font></td> <td><font face="Arial,Helvetica">M = 100 % * (W1 - W2) / W2</font></td> </tr> <tr> <td><font face="Arial,Helvetica">for building materials:</font></td> <td><font face="Arial,Helvetica">M = 100 % * (W1 - W2) / W1</font></td> </tr> </table> </ul> </td> <td></td> </tr> <tr> <td> <hr SIZE="1" WIDTH="100%"></td> <td></td> </tr> <tr> <td><a NAME="cm_method"></a><b><font face="Arial,Helvetica"><font color="#3333FF">CM-Method</font></font></b> <br><font face="Arial,Helvetica"><font color="#3333FF">A similar probe is to be taken as at the drying method, the probe has to be reduced to small pieces, than the probe has to be filled in a bottle, additional with metall balls and a carbide cartridge. The bottle has to be closed and the pressure is measured with a barometer. Than the bottle must be shakedn some minutes, the carbide reacts with the moisture and the result is a rising pressure. With the result of the pressure it's possible to calculate the moisture content. There are a lot of error sources,</font></font> <br><font face="Arial,Helvetica"><font color="#3333FF">Therfore the moisture result is not as accurate as the drying method!<b> In our opinion the  comparing measurements should be done with the <a href="#drying_method">accuratest method</a> and not with the CM-Method!</b></font></font></td> <td></td> </tr> <tr> <td> <hr SIZE="1" WIDTH="100%"></td> <td></td> </tr> <tr> <td><a NAME="conductance"></a><b><font face="Arial,Helvetica"><font color="#3333FF">Conductance measuring method</font></font></b> <br><font face="Arial,Helvetica"><font color="#3333FF">At least two electrodes has to contact the material which has to be measured, in the depth where the moisture value needs to be known. An amplifier measures the electrical resistance and a  linerisation module calculates the moisture value. The electrical resistance is also influenced through temperature differences, differenrt salt concentrations and the contact to the material. It's necessary to damage the floorings for measuring in the wished depth.</font></font> <p><font face="Arial,Helvetica"><font color="#3333FF">The highest moisture between the electrodes is most effective for the shown moisture result.</font></font> <br> </td> <td></td> </tr> <tr> <td><b><font face="Arial,Helvetica"><font size="+1"><a href="../../index.htm" target="_top">home</a></font></font></b></td> <td></td> </tr> </table> <br>  </body>