There are two types of breathalyser used by the police in Spain – one is a mobile design, used by the Police when out on patrol.
It is more rudimentary and less precise than the larger version that is used in Police Stations. This latter version is the definitive breathalyser and it is the results on this machine that are used to determine what action, if any, should be taken against a motorist.
So, in order for there to be a conviction for drink driving in Spain, the latter test must be carried-out. At this point is is worthwhile pointing out that the driver must submit to this test as a refusal will be considered a crime of disobedience.