I am afraid the FO gauge almost certainly reads only a representation of the rain not a measure of the rain. See here for calibration,
http://www.meteocercal.info/forum/Thread...07#pid2607
A good way of checking is to buy a plastic manual gauge with a decent diameter,(100mm to 150mm) and use it for a month or so.
http://www.ebay.co.uk/itm/The-REMEX-rain...SHDkFN0Y9g
http://www.meteocercal.info/forum/Thread...07#pid2607
A good way of checking is to buy a plastic manual gauge with a decent diameter,(100mm to 150mm) and use it for a month or so.
http://www.ebay.co.uk/itm/The-REMEX-rain...SHDkFN0Y9g