Compatibility Standard
International Electrotechnical Commission standard families specify electromagnetic compatibility requirements for electrical equipment used in measurement, control, and laboratory environments. Attaining IEC 61326 compliance demonstrates that an instrument operates reliably without emitting excessive electromagnetic radiation or suffering performance degradation from external field interference. Standard testing covers both immunity to environmental disturbances and limit compliance for radiated emissions.
Certification allows industrial instruments to carry international regulatory safety marks.
Immunity Limit
Laboratory evaluation subjects equipment under test to electrostatic discharges and fast electrical transients along power lines. Radiated radio-frequency field immunity testing verifies signal stability under intense electromagnetic fields up to six gigahertz. Conducted emissions limits restrict high-frequency noise fed back into plant electrical distribution wiring.
Enclosure shielding and power line filtering prevent unwanted RF energy leakage into surrounding workspace.
Certification Process
Technical compliance files documented by accredited testing laboratories form the legal basis for commercial product release. Demonstrating IEC 61326 compliance requires functional evaluation under specific operational modes defined in the product specification. Test plans specify performance criteria A, B, or C depending on whether temporary performance loss during disturbance is allowable.
Industrial location requirements enforce higher immunity levels than basic laboratory equipment standards. Shielded signal cabling and proper chassis grounding arrangements remain mandatory during immunity testing routines. Re-certification becomes necessary whenever major hardware or PCB layout revisions take place.
Installation Boundary
Calibrated biconical and log-periodic antennas measure radiated emissions inside anechoic test chambers. Surge generators apply standardized impulse waveforms up to two kilovolts to assess transient immunity bounds. Incomplete cable shielding or improper connector grounding causes immediate compliance test failure.
Unshielded sensor wiring acts as receiving antenna, introducing destructive transient voltages into internal electronics.
