General Tools and Instruments MM1E v.1 - Manual (Page 3)

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INTRODUCTION
Thank you for purchasing General Tools & Instruments’ MM1E
Pin-Type LED Bar Graph Moisture Meter. Please read this
user’s manual carefully and thoroughly before using the
meter.
The MM1E is designed for applications in woodworking,
building construction and home inspection. Examples include:
• Checking for moisture on or below the surface of
carpets and sub-flooring
• Measuring the surface moisture content of wood,
drywall and concrete before painting/wallpapering,
sealing or treating
• Locating water leaks in roofs, floors and walls
• Selecting dry lumber
The meter bases its measurements on the relationship
between the moisture content of a material and its electrical
conductivity. The wetter a material, the higher its conductivity.
The two replaceable steel pins at the top of the MM1E serve
as the electrodes of a conductance meter optimized for
measuring moisture content. The meter displays
measurements in the unit %WME (Wood Moisture Equivalent).
For hard materials like wood or concrete, the meter’s
readings largely reflect surface moisture content because:
1) Moisture close to a surface has a greater effect on a
reading than moisture deep below it; and 2) The pins of the
MM1E are only 3/8 in. (10mm) long and cannot be driven
deep into a hard material. For softer materials like soil, paper
or powders, readings are more likely to reflect the average
moisture level of the material between its surface and the
penetration depth of the pins (normally far less than 3/8 in.).