EMC Mobile Station

The EMC mobile station is used to measure EMC (relative humidity) in a dry kiln or stacked lumber in air drying facilities, sheds, warehouses, storage areas. The mobile station is complete with EMC holder, mounting plate and a slide to fit between two layers of stacked lumber. EMC measurements can be obtained with a moisture meter, in-kiln monitor, or the kiln control systems.

Measurements can also be obtained with wireless transmitters. The advantage of using transmitters and receivers is that measurements are send to the receiver and PC without needing any in-kiln wiring. Making the unit completely mobile to find the best location inside kilns or pre-dryers.

EMC or equilibrium moisture content are directly related to Wet-bulb dry-bulb measurements and relative humidity and temperature. The corresponding values for these parameters are given in the EMC charts. (See Documentation below.)

Item Number: K-EM


Product Description

The EMC mobile station is used to measure EMC in dry kilns, pre-dryers, air drying yards or other places where lumber is stacked for drying or storage.

The mobile station comes with an EMC holder, a mounting plate and a slide to fit into stacked lumber, it can be connected with a PK-H cable to a switch box or via adapter H directly to the Ligno-VersaTec or the Lignometer K.

If the mobile station is part of a wireless monitoring system or kiln controller, the transmitter can be mounted directly on the mobile mount. Biggest advantage for the kiln operator is the complete mobility of the device. He can change the measuring location easily, just move the device higher or lower up and down the lumber stack. Further, there are no cable runs to take care of and there is no water supply needed to keep the wet-bulb thermometer measuring correctly.

Mobile station, EMC holder and angle connector are made from aluminum, stainless steel and teflon to withstand the corrosive air and hot temperatures inside a drying chamber.

Using EMC wafers in dry kilns to measure humidity is an excellent choice. The cellulose EMC wafer is inexpensive, reliable and not affected by the corrosive air nor by high temperatures inside lumber dry kilns. Measuring elements in relative humidity probes and thermo-hygrometers will likely be destroyed within a few months by the corrosive air in a dry kiln. Wet-bulb dry bulb thermometer stations are cumbersome to maintain. Lignomat has used EMC measurements with cellulose wafers in lumber dryers and predryers for over 50 years.

Measuring EMC: The cellulose wafer quickly reaches an equilibrium with the surrounding air wherever it is placed, inside a dry kiln, air drying shed, warehouse, shop, house or office. To obtain EMC measurements, connect the Ligno-VersaTec or the Lignometer K, select the EMC setting and the correct temperature and the meter indicates the EMC value for the relative humidity and temperature of the surrounding air. The kiln control systems and wireless monitors automatically correct for the EMC setting and the temperature and produce corrected EMC values.

EMC Charts: Corresponding values for stable conditions of relative humidity / temperature and wood moisture content are listed in the

— EMC-Chart up to 100°F
— EMC-RH-WB Chart up to 210°F
— EMC-RH-WB Graph for kiln-drying up to 260°F

At a temperature of 70°F and 45% relative humidity, the EMC according to the chart is 8.5 %.  That means, wood with a moisture content of 8.5% is stable, it will not absorb or loose any moisture, will not shrink, warp or cup. If wood in the same ambient conditions has a moisture content of 10.5%, it will loose moisture until 8.5% has been reached. This loss in moisture can cause wood movement depending on wood species, wood thickness and time of exposure.

Looking at drying conditions in dry kilns or wood sheds: If the moisture content of wood is 15% and the EMC of the surrounding air independent of the temperature is also 15% no drying will take place. If the moisture content of the wood would be 22%, there is a moisture gradient and the wood will dry. Lignomat has been using EMC measurements from cellulose wafers for over 50 years to control the drying process in kiln control systems.


— EMC wafer
— EMC mobile mount: EMC holder with plate to slide into stacked lumber
— PK-H cable to plug into angle connector, measuring station and mobile mount.

— Ligno-VersaTec
— Lignometer K
— Wireless monitor
— Kiln control systems

mini-Ligno DX/C can be used, but the accuracy above 10% may not be enough. Lignometer and VersaTec indicate moisture with a 0.1% resolution for the entire range.

For more information please contact Customer Service at 1-800-227-2105.

Lignomat USA Ltd, 14345 NE Morris Ct., Portland OR 97230, USA,
Email: sales@Lignomat.com, www.Lignomat.com