I'm having an awful time finding a hygrometer under $50 that is rated by users as accurate. How accurate should it be? Within 5-10% ? I'm in the desert and our humidity usually runs about 5-8% outdoors, 25% indoors, so this is a concern for my next hatch as the last one was not successful. I'm using a Brinsea probe thermometer in a Little Giant 'bator with fan and turner.