BS ISO 5348:2021 pdf download.Mechanical vibration and shock – Mechanical mounting of accelerometers.
The method most commonly used for determining the vibratory motion of a structure or body is the use of an electromechanical vibration transducer, also called a transducer or a vibration sensor. These vibration transducers can be divided into the two broad classes: non-contacting and contacting transducers.
Non-contacting transducers are relative measuring transducers recording a motion in relation to a fixed space coordinate system. Typical examples are eddy-current probes, optical sensors and laser vibrometers. These transducers have no direct mechanical contact with the structure and are therefore not dealt with in this document.
Contacting transducers are mounted onto the structure by mechanical coupling. This includes, for example, piezoelectric, capacitive and piezoresistive accelerometers as well as seismic velocity transducers. These absolute measuring transducers record the motion by seismic forces from the space coordinate system onto which they are mounted. If such a transducer is mounted onto a structure, the properties of the mounting can significantly influence the frequency response of the structure as well as the vibration transducer. Very large measurement deviations can occur in case of lack of care in the mounting property, particularly at high frequencies.
Under certain circumstances the mass, geometry and mounting stiffness of the transducer can directly
BS ISO 5348 specifies the important technical properties of the different methods for mounting vibration transducers and describes recommended practices. It also shows examples of how accelerometer mounting can influence frequency response and gives examples of how other influences can affect the fidelity of the representation of actual motion in the structure being observed.
BS ISO 5348 applies to the contacting type of accelerometer which is currently in wide use. It is applicable to both uniaxial and multi-axial transducers. This document can also be applied to velocity transducers.
BS ISO 5348 enables the user to estimate the limitations of a mounting and consequent potential measurement deviations.
Transducer mounting issues are not the only problem that can affect the validity of acceleration measurement. Other such problems include, amongst others: transverse movements, alignment of the transducer, base bending, cable movement, temperature changes, electric and magnetic fields, cable whip and mounting torque. Issues other than mounting and their possible effects are outside the scope of this document.BS-ISO-5348-2021