Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: very worrying device

I dont know whether the Tanita Breath alert is accurate or not. There is very little information available, other than one site, http://www.halimeter.com/bostonchannel1.html, which offers the advice that it is overly sensitive and gives high readings for the majority of those tested - did they all have bad breath that day? I know that it has given very erratic readings (both high and low), and I have been unable to find any informaion, on the Tanita Website, or anywhere else, which gives correlations between the tanita readings and the ppm readings that you would expect from a Halimeter. The device has affected my confidence considerably, and I would caution those who are wanting to know if they have a problem, that this will make your fears worse. I am off to the dentist!