ComProTec Canada - Manufacturers of the Timber Check Moisture Meter

Pin-type vs. pinless meters

Pinless moisture meters have the distinct advantage of not damaging wood surfaces during testing. Unfortunately they are very expensive. They also have other disadvantages;

Pinless meters do not provide accurate reading on wood with rough surfaces. During testing it was found that a surface roughness of .02 inches on a 16% wood sample will produce a reading of 12% on the meter. If the wood surface is then planned, the meter then reads the correct 16%.
The wood sample being tested must be wider than the meter .
The wood sample must not be cupped since close contact between the back of the meter and the surface is very important.
Pinless meters cannot read deep into a sample and sensitivity beyond the surface drops off quickly. Most pinless meters provide an average reading of the first 5/8" depth of wood. With pin-type meters this problem can always be overcome with the use of nails driven into the sample to be used as long probes.
If the surface is damp (dew) the sample will read high. This is true for resistance meters as well however with the use of insulated nails as probes the problem can be overcome. This is not the case with the pinless meter.

Pinless meters do have the advantage of not producing small hole in wood samples but they offer no flexibility for reading rough, narrow, thick or unevenly wet wood.