Category I

Personnel classified to category I shall at least:

a) know of the basic principles of vibration and recognize the different units of measurement;

b) be able to collect reliable data ensuring appropriate standards of repeatability;

c) be able to identify errors in collected data;

d) be able to retrieve pre-defined measurement settings for use with VA equipment and transfer data from an analysis system to a computer-based system;

e) be able to compare overall or single-value vibration measurements against pre-established alert settings;

f) be able to identify deviations from the norm for single-value vibration values and trends

g) report on visual observations of equipment

They shall not be responsible for:

  • the choice of sensor, test method or technique or for any analysis or diagnosis to be conducted;
  • the assessment of test results, other than identifying conditions against pre-established criteria, such as acceptance, alert, alarm, shutdown, etc

  Category II

Personnel classified to Category II require all the knowledge, experience and skills expected of category I, and in addition they shall at least:

a) be able to define the measurement activities to be undertaken by a category I individual in the course of routine data collection;

b) be aware of and capable of using the basic principles of signal analysis and, as such, can define acquisition and analysis settings to collect data appropriate to the machine(s) monitored;

c) be able to perform basic (single-channel) impact tests to determine natural frequencies;

d) be able to interpret and evaluate test results from routine analysis and acceptance tests in accordance with specifications and standards;

e) be able to diagnose common fault indications and recommend basic corrective actions commensurate with their area of machinery experience including carrying out single-plane balancing of rigid rotors with or without phase;

f) be able to provide technical guidance to and instruct category I


Category III

Personnel classified to category III require all the knowledge, experience and skills expected of personnel classified to categories I and II, and in addition shall at least:

a) be able to design, direct and establish routine condition monitoring programmes and non-routine investigations for the purpose of fault diagnosis;

b) be able to specify the appropriate vibration instrumentation hardware, software, and processing for portable monitoring systems, permanently installed surveillance systems, and equipment protection systems

c) have an in-depth knowledge of the principles and techniques of machinery VA and be able to make initial diagnoses of suspected faults beyond the range of commonly encountered This should include, but not be limited to, the use of frequency spectra, time waveforms and orbits, transfer functions, basic operating deflection shapes, and acceleration enveloping under both steady state and transient conditions with or without a phase trigger;

d) be able to manage such condition-monitoring programmes, evaluate the alarm sets, write working procedures and specify vibration acceptance testing procedures;

e) be able to initiate and validate machinery corrective actions including in situ two-plane rigid rotor balancing;

f) be able to recommend restrictions to machine operation;

g) be able to understand and direct, when necessary, alternative condition monitoring technologies to verify or investigate issues raised through routine data collection;

h) be able to provide technical guidance to and instruct category I and II personnel, and, subject to agreement with the employer or client, deem them competent to carry out certain duties which would normally be outside the scope of those competencies.

It is the responsibility of the employer or client to ensure that category III personnel have the necessary competency in the required management skills, e.g. creating budgets, preparing cost justifications, and managing personnel development.


Category IV

Personnel classified to category IV require all the knowledge and skills expected of category I, category II and category III personnel. In addition, they shall be able to direct and audit condition monitoring strategies.

In addition, personnel classified to category IV shall at least:

a) be able to apply vibration theory and techniques, including measurement and interpretation of multi-channel spectral results such as frequency response functions, phase and coherence;

b) be able to understand and perform signal analysis, including understanding of frequency and time domain processing, including orbits and their limitations;

c) be able to determine the natural frequencies, mode shapes and damping of systems, components and assemblies;

d) be able to determine and assess the operating deflection shapes of machines and connected structures and recommend means for correction;

e) be able to use generally recognized advanced techniques for VA, parameter identification, and fault diagnosis;

f) be able to apply the basic principles of rotor-bearing dynamics to vibration diagnosis;

g) understand and apply advanced two-plane influence coefficient or static and couple balancing theory;

h) be able to recommend corrective actions or design modifications, including component change or repair, isolation, damping, change of stiffness and change of mass;

i) be able to interpret and evaluate codes of practice and specifications published in International Standards and other documents;

j) be able to recognize vibration caused by gas pulsation in machines, such as reciprocating machines and screw compressors, be able to measure the necessary parameters, and recommend means for correction;

k) be able to recommend corrective actions for resilient mounting and other holding-down and foundation problems.