Moisture Content Control During Drying – TRUMARK-EVO

30 November 2023

Concurrent with the progression of drying technologies towards continuous drying systems (CDS) the importance of knowing the moisture content (MC) of the timber during drying is essential. Traditionally this has been from an “end point” perspective i.e., when the average target MC has been achieved.

Today’s timber drying operations need to monitor the rate of drying from “green to dry”. There are two main driving factors. The first is the focus to reduce overdried timber, which wastes energy (thermal and electrical), increases distortion and reduces drying capacity.  The second is the desire for automated moisture control drying to consider product change (a change in board thickness), differing winter vs. summer drying times, a change is species being dried and the problem of getting log resource from various locations.

The Challenge

  • Accurate MC measurement above and below fiber saturation
  • Seamless integration of Wellons Winkiln and Winkiln-Evo control software.
  • Automatic push rate adjustment in CDS units.

The Solution

As part of our R&D program, Wellons has developed a “wireless” MC monitoring system called TRUMARK-EVO.  The TRUMARK-EVO MC sensors travel down the length of the CDS unit monitoring the lumber MC as the lumber progresses through the drying process. In a two track CDS (counter flow or parallel flow design) different product or species can be dried on each track.

Control Integration

TRUMARK-EVO operates in conjunction with Wellons’ computerized control system (Winkiln-Evo) to automate the drying process. The MC of the lumber is measured throughout the drying process, while Winkiln-Evo continually monitors and adjusts the drying process. 

Description of Equipment

The TRUMARK-EVO system typically includes the following components:

  • Communications Panel to interface between the control computer and distribution panel(s).
  • Distribution Panel to interface with sensor assemblies.
  • Sensor Assemblies consisting of the sensor plates and transmitting sensor panels. 
  • Antennas consisting of transmitting antennas, receiving antenna panel and grounding support. 
  • RFID Reader to identify the sensor assemblies as they enter the drying chamber.

Ease of Installation

The system requires no major changes or modifications to the drying system. Transmitting and receiving panel installation, and interconnecting wiring, can be done by the mill electricians or an electrical contractor. 

Ease of Use

The system requires minimal additional operator training. Sensor plates are durable, and are easy to use. 


TRUMARK-EVO requires minimal maintenance components are designed for the harsh conditions found in lumber drying systems, including high temperature applications. 

Durable stainless-steel sensor plates require no special handling or cleaning. The TRUMARK-EVO distribution and sensor panels require no maintenance and are designed for simple installation and easy access. 

Source: Wellons