Tanita HC-212F Breath Checker is a device that helps you monitor your breath odor level. It has a semi-conductor gas sensor that detects and measures the presence of volatile sulfides and hydrocarbons in the breath and displays the degree of odor in six levels. The device is easy to use. Just put the cap in the up position and the sensor will turn on. The number on the display will count down from 5-1, and then the “START” will be displayed. Do not breathe into the sensor. Wait for “E” to start flashing. Then breathe into the sensor until it beeps (breathe for about 4 seconds).