Nothing to worry about with your readings.
Time to start investigating is above 20% depending on time of year and ambient conditions.
30% and above and you have problems which need attention.
Yes under 20% is no problem. I assume you have one with a wooden frame and there is always a certain amount of moisture in that so if you cannot get a nil reading.
Hutch.
what was the reading pre repair?
Since I sorted out the internal tank and tap leaks I've gone down from 48% to 12%
Will test again in a few weeks.
When we checked at the last Woosie fest His Highness, Sproket, at the time checked it an came out at 15 % all about. Bought the meter same as your and got readings 12 to 15 % Coachman returned my now imaculatly repaired caravan and I checked the damp at 12 to 15 % so I am now happy to know this is a normal level. Thanks tomall.
Just been the "Caretaker" for a mates Bailey Unicorn S3, and had it serviced today, and although its been on his driveway, unused, for a year now and I have only been into it three times, the damp levels throughout the van were at 8% very nice.
The service engineer suggested that cat litter is good for anyone with damp, as it will absorbe upto 10 times its own weight.
Going back tomorrow and check my £20 meter to his readings.