3.1.1 Where
calculations indicate the possibility of significant lateral vibration
responses within the range of working speeds, measurements using an
appropriate recognised technique may be required to be taken from
the shafting system for the purpose of determining that hazardous
whirling or excessive vibration does not occur.
3.1.2 The method
of measurement is to be appropriate to the machinery arrangement and
the modes of vibration which are of concern. When measurements are
required, detailed proposals are to be submitted in advance.