Level 3 Examination
Location: Sheffield, UK
The objective of the Level 3 examination is to enable candidates to show that they have a broad knowledge of strain measurement methods and component behaviour, can evaluate strain gauge installations made by other personnel, and can make measurements using strain gauges and determine accurate values of stress.
- a practical test
- a written test
- an interview
The practical test
- a stress analysis task using pre-installed strain gauges, is based on measurements using strain gauges already installed on a component. It normally includes the use of rosettes, the correction of raw data, and the determination of principal values and the yield load.
- a load measurement task using pre-installed gauges is normally based on a body carrying six gauge grids. Appropriate grids are selected and used in a bridge circuit to achieve relationships between load and the bridge output.
- a written evaluation of a strain gauge installation, which requires the preparation of a short report. This is usually based on an examination of the installation, and the original specification for the installation.
The written test is held on the morning of the second day and has two sections:
- a basic section, containing questions based on general knowledge related to
(a) component behaviour and
(b) methods of strain/stress analysis
- a section containing questions based on the use of strain gauges
The Interviews are held after the written examination on the second day. The interview is conducted by three members of the Certification Committee and lasts around half an hour. It is concerned with:
- education and training
- experience in the analysis of strain and stress
- understanding and breadth of knowledge of strain measurement and stress analysis methods
- responsibility for gauge installations and test programmes
- supervisory experience
The candidate is expected to submit a summary of relevant work done over a period of around two years. At the interview candidates normally use additional supporting material such as photographs, drawings, graphs, models, samples and components.
It is highly recommended that candidates attend the one day pre-examination seminar is normally held about two weeks before each examination, so that candidates can make installations under examination conditions and discuss procedures, techniques and the sample written questions with an experienced engineer. It is normally held at the examination venue.