NMR hand-held moisture sensor

An open magnet design, hand-held NMR sensor head is presented. Wood moistur e content and cement hydration tests demonstrate the potential of the tool for in-situ material assessment. The magnetic field distribution was adjust ed by positioning blocks of permanent magnets using millimeter scale 3-dime nsional magnetic field modeling. A low Q-factor circuit was used for spin-e cho sequences with short echo times. (C) 2001 Elsevier Science Inc. All rig hts reserved.