I use a Sovereign Quantum Marine Moisture Meter which is the most advanced meter on the market and which is specifically designed for the taking of moisture readings on GRP laminates. The UK company Sovereign Chemicals has a history with yacht surveyors and boatyard osmosis technicians.
It is not enough to just own and use a moisture meter, the readings can be interpreted incorrectly by an inexperienced operator.
I was trained at the International Boatbuilding Training College, Lowestoft for the use of this particular model of meter in assessment of GRP laminates and wood.
There is a calibration feature by which the calibration of the unit can be checked before the survey by touching the probe against the calibration pad and checking that the deep and shallow readings are the correct values.
The unit also can measure some atmospheric values as seen above. This means that the conditions at time of survey can be quantified which makes the measurement more scientific and will enable checking that condensation will not be occurring and affecting the readings.
The unit offers both deep and shallow modes which are essential for finding the location of moisture in the laminate.
Sep/09 I had the meter upgraded to include a deep/shallow mode button on the probe which is much more convenient. The meter was also upgraded to latest software 3-9.
From my personal testing over many surveys I am very confident in the readings of this meter and my interpretations.