The Sober Check SC3000 breathalyser is an entry-level, personal unit, designed to give you an indication of your breath alcohol level.
The SC3000 uses a semi-oxide sensor to detect the level of alcohol on the breath.
This unit is certified by the US Department of Transportation.  It is calibrated to New Zealand’s drink drive level.

Recalibration is recommended every 6-12 months under normal personal use, although it may be required more or less frequently dependent upon the amount of alcohol registered by the sensor.  You will be able to identify the need for recalibration as the unit will measure significantly higher or lower than usual.