DIN EN 61689:2008 Ultrasonics - Physiotherapy systems - Field specifications and methods of measurement in the frequency range 0,5 MHz to 5 MHz (IEC 61689:2007); German version EN 61689:2007
2013DIN EN 61689:2013 Ultrasonics.Physiotherapy systems.Field specifications and methods of measurement in the frequency range 0,5 MHz to 5 MHz (IEC 61689:2013); German version EN 61689;2013
2008DIN EN 61689:2008 Ultrasonics - Physiotherapy systems - Field specifications and methods of measurement in the frequency range 0,5 MHz to 5 MHz (IEC 61689:2007); German version EN 61689:2007