Hi Alan -- I have the little cheap one that Axminster sell for around £20, it does the job
well enough. We have a few surveyors in work that do house inspections and they carry
really expensive things that the tax payer pays for to measure for damp and there is very
little difference. Does it matter that a £250 model says a bit of wood is 22% and my
cheapy says that it's 20% ? Mine has never been calibrated (if it's possible) the works one
is done twice a year ! -- Julian