Instruct: Classify a given review as either positive or negative.
Query: humidity sensor not accurate at all

I have two same Planet Waves humidity sensors. Don't trust any of them as putting both side by side I have completely different readings of humidity (like 34% versus 25%). Sometimes units having less difference in readings, but had never been less than 3%. This is crap unit with no stability and accuracy. I should mention that Hunidifier itself works fine and I use it as well as Humidity controls pack I have.