Damp meter

Think you need one?

https://www.aldi.co.uk/en/specialbuys/thursday-4-september/product-detail/ps/p/digital-moisture-meter-1/

Hi Paulmold,

Interesting subject these devices aren't they? As I understand it (and I'm no electronics expert) these are nothing more than an ammeter so they indicate the flow of electrons. The presence of water helps the flow of electrons, so the more the moisture, the more the indication of electron flow.

The danger with the type of meter on offer in the link you quote is from the metal probes that have to puncture the surface of the article being "damp tested".

I witnessed the sales guy at the dealership where I traded in my beloved Rapido 7099f using a "damp meter" on it (I'm sure he would have offered a much lowered trade in price had anything been indicated, and they had given me the absolute minimum they could get away with - cheapskates). His device was a non-contact model - it made no puncture marks in his new vehicle accepted from me. I would be interested to hear from anyone who knows, how reliable the indications are from these non-contact "damp meters"? And, how do they 'sense' dampness (ultrasonic signals?)

I hope I don't need one, if I do, I would have to consider a non-contact model because I can't bear the thought of puncture marks all over the internals of "Winnie". I bought from this dealer (at top whack price) my latest beloved brand new motorhome. Perhaps someone within ASOF will reasure me that new A/S vehicles are leakfree, I hope???

Barry.

The non-invasive damp meters that dealers use cost in excess of £150. I've got one of the Aldi ones and yes pin-pricks where you stick it, so I only use it where it doesn't show and the biggest problem is that most of the walls low down are covered in fabric and you can't really get a reading of the wall/floor beneath. There are non-invasive ones available (from China/Hong Kong of course) at a fraction of the cost of professional ones but whether any good I couldn't say.

professional one - http://www.ebay.co.uk/itm/Protimeter-Aquant-Moisture-Meter-2-Non-Invasive-Damp-Meter-BLD5765-/370998450942?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item56613b1afe


cheapo one - http://www.ebay.co.uk/itm/Digital-Non-Invasive-Inductive-Moisture-Meter-LED-4-modes-Wood-Drywall-Masonry-/271585603573?pt=UK_Sound_Vision_Other&hash=item3f3bc36ff5

Has anyone used the Aldi meter and if so have you found it accurate and how noticeable are the pinholes it leaves? 
Also has anyone purchased the cheaper non invasive type from Hong Kong and found it to be accurate?

As I said I've got an Aldi one. How accurate it is I don't know but it can certainly show a damp area against a dry area. The pin pricks aren't noticeable really but I wouldn't use it on the ceiling. What it is lacking is illumination of the scale, when you use it down low and inside cupboards you need to shine a torch on the scale to see it. I had a small area that gave a reading of over 40%, had the seam resealed and over a period of time, as it dried out the reading reduced to less than 10%.

So would you use the probes into the carpeted areas under the seats for example Paul?

I don't think the pins would give an accurate reading unless you could get through the carpet to the wood behind. Same goes for vinyl. Our undersink cupboard has cushion-floor vinyl on the floor.Putting the pins in the vinyl gave a very high reading. Lifting the vinyl and putting the pins into the wood floor gave a very low reading. So I think some materials have a high moisture content. The non-invasive metres detect to a depth of more than 1.5 cm so I would think they would be better at detecting moisture behind carpeted walls etc.