Instruct: Classify a given review as either positive or negative.
Query: Unacceptable for serious work.

I have had to send two of these back for the same reason. When I returned the first one, the company said it must have been a defective unit, but the replacement one does the same thing.The problem is that the MIN/MAX function does not work properly. Even when recording very steady sine wave acoustic signals well within the device's measurement range, the unit often reports that the MAX signal value encountered during the recording period was too LO to be recorded. And about as often, that the MIN signal level encountered was too HI to be recorded. This obviously makes no sense, and points to a problem with the device's data acquisition or a software bug.If you just want to look at the numbers flickering by and make a guess about maximum, minimum, and average values over a time period, this might work for you, but for any serious quantitative engineering or scientific work, forget it. It's a hobbyist level tool at best, not a professional tool.