potentially explosive atmospheres. The work of EECS originated with the Safety in Mines Research Establishment in 1926, when testing of mining equipment to prevent explosions was started in Buxton.  That work continues with the Mining Equipment Certification Service (MECS), a division of EECS. With the growth of the petrochemical industry in the 1950s and 1960s, the need for standards and a certification services outside of the mining industry led to the development of the British Approvals Service for Electrical Equipment in Flammable Atmospheres (BASEEFA). In 1987, MECS and BASEEFA were brought together to form EECS. Effectiveness A measure of the degree to which an item, system, or person can be expected to achieve a set of specific mission requirements. Performing the correct task efficiently. Efficiency In a general sense, efficiency relates to competence: the ability to do something well or achieve a desired result without wasted energy or effort. In engineering terms, efficiency is a measure of a machine's energy effectiveness: the ratio of the amount of energy used by a machine to the amount of work done.  For example, the measurement of the amount of heat produced per unit of fuel burned is a measure of a heating unit's efficiency. Electrical Current Analysis An investigation of the electric current (spectrum) of electric motors or generators. Through this analysis, irregularities (e.g. broken rotor bars, cracked end-rings, high resistance joints) are detected. Specialized tools and personnel exist for doing these investigations. Electronic Data Interchange (EDI) (EDI) links-Information-system linkages, based on communication