2.0 Key Terminology and Application Methods
Precise, standardized definitions are fundamental to achieving compliance and ensuring the validity of test results. These terms remove ambiguity in test execution and reporting, which guarantees that results are comparable and reproducible, regardless of the testing facility or personnel involved.
Table 1 – Core Terminology per IEC 255-22-2
| Term | Definition per IEC 255-22-2 |
| Contact discharge method | A method of testing in which the electrode of the test generator is held in contact with the equipment under test and the discharge to the equipment under test is actuated by the discharge switch within the generator. |
| Air discharge method | A method of testing in which the charged electrode of the test generator is approached to the equipment under test, and the discharge is actuated by a spark to the equipment under test. |
| Direct application | Application of the test directly to the equipment under test. |
| Indirect application | Application of the test to a coupling plane in the vicinity of the equipment under test, and simulation of personal discharge to objects which are adjacent to the equipment under test. |
The standard mandates that Direct application of the test to the equipment shall be used. The Contact discharge method is designated as the preferred method for application to all conductive surfaces of the EUT. The Air discharge method is to be used only for those accessible surfaces that are non-conducting. The Indirect application method is explicitly stated as not being applicable to static measuring relays and protection equipment under this standard.
These defined methods are applied at varying levels of intensity, which are categorized into distinct severity classes.