Extech MO55 Kombinations-Feuchtigkeitsmesser mit Stift/Stiftlos, Grün

Advantages: Pin and pinless mode in one instrument. The pinless mode allows quick scanning of walls. The device seems to give the correct general behaviour i.e. damper materials give higher readings and (usefully) faster beeping when sound is on. So far, the readings seem reasonably reproducible - going over the same area again give more or less similar readings. It isn't expensive.Drawbacks: Absolute readings in pinless mode do not seem credible (it overestimates - bone dry plaster on block reads about 19%). The pinless comparison mode (whereby you can zero the device on a known dry material before testing damp specimens) does not work - the device does not zero when switched on in contact with the dry reference.

I have a Brennenstuhl model, that has only pins, pins are ok for wood an brick but not so good for detecting wood panels in a motorhome or caravan, this works as a scanner, so is easy to use.Dont listen to keyboard warriors who claim they have a £300 scanner and this is inferior, IT DOES WHAT IT SAYS ON THE TIN, detects Water Ingress, and Damp Panels.

Very useful tool in checking for hidden excess dampness in buildings and materials without leaving any marks or surface puncture damage. Quick to use with options for either surface testing pins or non damaging deeper embedded moisture and also choice of wood or general building material. Works well with wood, blocks, concrete, plaster ect. Even locates damp areas behind 'foil backed' plasterboard. Have found it can gives a false positive sometimes with some natural building stones, but this can be checked against known dry sample. Readings should be treated as indicative of relative dampness, which it is good at, although as with all these meters a digital reading calibration function would have been useful.Easy to use, clear large display. Good value. Highly recommended.

Using the meter in "pin" mode gives reasonably believable results on a masonry wall. But in "pinless" mode, the readings are not even close (always much, much higher - even a bone dry internal wall measures at 19%, i.e. "medium" dampness). Furthermore, the "pinless comparison mode" simply doesn't work in the way described in the manual - and I'm not the first reviewer to note this. Two stars as the product appears to work as a "pin" moisture meter... but if that's all you need, there are much cheaper products than this one. Returning for refund.

Used it to successfully locate the source of damp in our kitchen and one of the bathrooms. Thanks to this handy little device we didn't have to tear up the entire rooms to find the problem, which turned out to be a leaky pipe in both cases. We could pinpoint where it was wettest and then just remove that tile, and in fact that's where the problem originated from.We found it very easy to use despite having virtually zero DIY experience, and well worth the investment. Will definitely be using this regularly to check the bathrooms and kitchen in our place.