This part of ISO 18312 specifies a method for evaluating the vibration power emitted by machines or pipelines,
referred to hereinafter as machines, under operational conditions on to supporting structures to which the
machines are directly connected via bolted joints. This part of ISO 18312 specifies the method for evaluating
the vibration power components emitted in the six degrees of freedom of a Cartesian coordinate system at
each joint, i.e. three translations and three rotations. The vibration power is determined by processing the
signals from force and velocity (or acceleration) transducers mounted on to the bolted joints under operational
conditions of interest. This method is applicable for machines under the assumption that their vibration can be
characterized by a stationary random process.
The components of emitted vibration power in the frequency domain are obtained by computing the
cross‑spectrum of the force and velocity measurement pairs with a given narrow band width at each bolted joint.
This direct method assumes that the supporting structures are adequately rigid and, hence, it is not applicable
to cases where the foundation or supporting structures are resilient, which will potentially go into a state of
resonance within the frequency range of interest. Practical frequency limits of the method are specified in this
part of ISO 18312.
This part of ISO 18312 can be used in operational conditions for:
a) specification of vibration power emission of machines at the (bolted) joints;
b) identification of vibration power severity;
c) resolving diagnostics issues;
d) planning vibration control measures.