Small resistive wood moisture sensors: a method for moisture content determination in wood structures

Summary, in English

The wood moisture content influences the service life of wood structures since wood is susceptible to decay by rot fungi if it is exposed to high moisture contents during long periods of time. In rain exposed structures, the moisture content close to end grain surfaces and joints can be significantly higher than the average moisture content, but moisture content determinations at such locations require small moisture content sensors. This paper presents small resistive moisture content sensors fastened by electrically conductive adhesive. The relationship between moisture content and electrical resistance was determined for Norway spruce (Picea abies (L.) Karst.) for a wide range of moisture conditions achieved both by equilibrating specimens over saturated salt solutions and by the pressure plate method. The error, i.e. the difference between the gravimetric moisture content and the moisture content from the regression equation, increased with increasing moisture content. Neither the wood type (heartwood/sapwood) nor the growth rate (southern or northern Sweden) influenced the resistance-moisture content relationship.

• Author: Maria Fredriksson; Lars Wadsö; Peter Johansson
• Department/s: Division of Building Materials
• Publishing year: 2013
• Language: English
• Pages: 515-524
• Publication/Series: European Journal of Wood and Wood Products
• Volume: 71
• Issue: 4
• Links: http://dx.doi.org/10.1007/s00107-013-0709-0
• Document type: Journal article
• Publisher: Springer
• Topic: Materials Engineering
• Keywords: Content determination; Electrical resistances; Electrically conductive adhesives; High moisture contents; Picea Abies (L.) Karst; Pressure plate methods; Saturated salt solution; Wood moisture content
• Status: Published
• ISBN/ISSN/Other: ISSN: 0018-3768