IEC 60601-2-26:2012 standard applies to basic safety and essential performance of electroencephalographs used in a clinical environment (e.g., hospital, physician's office, etc.). This standard does not cover requirements for other equipment used in electroencephalography. This third edition cancels and replaces the second edition of IEC 60601-2-26 published in 2003. The aim of this third edition is to bring this particular standard up to date with reference to the third edition of the general standard IEC 60601-1:2005 Edition 3, through reformatting and technical changes.