I've got a cheap digital humidity meter, and a cheap analog one, and an expensive dehumidifier with a humidistat. Before running the dehumidifier, the humidity was around 70-80% according to all three. I ran the dehumidifier flat out for a couple of days and it removed huge quantities of water, and I can feel the air is dry in my throat. Its humidistat reads 31%, which I can believe - everything is bone dry, no condensation, clothes hung indoors dry rapidly, yet the 2 meters are reading 65%! At various times the 2 meters sometimes agree and sometimes are out by 15-20%. I've calibrated them using the damp salt method to 75%, but they suck when it changes from that. Where can I get one that actually works?

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Why do they call it a TV set when you only get one?