We use several of these machines at a sober living facility. They are reliable, accurate and easy to use. The calibration is done here after several hundred uses and is a quick and easy process that that keeps the machines working well. I only wish the machine provided notification as to when it may need re-calibrated.
Unit is well used over the last year plus. Sent in for calibration and it was returned very quickly. Don't send in batteries. The unit will come back without.
I recently had this device calibrated within the past 60 days. And it now reads 0.000 on all blows regardless. It no longer can pick up a reading, regardless of alcohol consumption and has failed me.
I bought my Breathlizer Mobile one and a half years ago. It has worked fine, but knowing that you have to calibrate it once a year makes you doubt the readings once you are close to the 12 months. I wish you made one tha doesn't need calibration in order to give them as gifts to all of my friends and relatives. Thanks for this product.