I use the machine mostly in the morning after a party to see if I could drive a car again. Even at parties is part of a nice gag) After inserting the batteries have to the Power switch Press for two seconds to turn the unit on. After a 15-second warm-up period of the sensors, it blows evenly in the device to this, unfortunately a little too loud beeps. It measures almost exactly and it can be output even in three units the result: parts per thousand, and percent mg / L.
Very handy, I find that the five test tubes are built into the device back. These can be washed after use and do short hot back into the device.
Super, I can here express an absolute recommendation!
