HL Deb 04 July 1986 vol 477 c1252WA
The Marquess of Ailesbury

asked Her Majesty's Government:

Whether the type of breathalyser used by motorised police is so adjusted as to give a positive reading at precisely the legal limit.

Lord Glenarthur

All types of roadside breath screening devices approved for use by the police are designed or adjusted to operate, within acceptable tolerances, at the prescribed legal limit.