Instruct: Classify Amazon reviews into positive or negative sentiment
Query: piece of junk

This thermometer is completely inaccurate pretty much every time. I didn't know that when I started measuring my temperature every morning for my fertility charting and worried myself sick why on earth my temperature jumped all over the place, from 96.5 to 98. But then I read various reviews on Amazon and decided to go with the following beautiful and reliable machine: mercury-free glass thermometer. I suppose the key phrases here for me were that this new thermometer was not digital and that it is supposed to be certified accurate. I did a few side by side comparisons and the temperature on the digital one never makes any sense, still.