Technical notes written by people who ran an accredited EMC laboratory before they supplied one. Standards-based and practical, with no brochure language.
Each note takes one question we are asked in laboratories and answers it from the standard, in enough depth to act on.
What CISPR 16-1-2 and IEC 61000-4-6 actually ask a LISN, ISN or CDN calibration to measure, why a raw S21 is not a voltage division factor, the uncertainty terms a plain S-parameter budget leaves out, and how to read a scope or a certificate in two minutes.
7 minute read Test methods · AmplifiersThe saturation check and the harmonics check of IEC 61000-4-3: what the 5.1 dB step proves, why harmonics should stay 6 dB below the fundamental, and what each fault does to the test.
8 minute read Test methods · ChambersThe uniform field area of IEC 61000-4-3 in plain words: the upright square, its sixteen points, the twelve-of-sixteen rule in V/m, both polarisations, and a 3D simulator from 80 MHz to 6 GHz.
8 minute read Test methods · ChambersCISPR 16-2-3 Amendment 1 ties the largest EUT to the measurement distance: 1.5 m at 3 m, 2.0 m at 5 m. Where it is cited, what it changes now, what is coming, and why 5 m is the sensible step.
10 minute read Site validation · AutomotiveFour editions, four answers to how an automotive component chamber is proved fit for use, and the one that survived: the long wire antenna method of Edition 5, how it works and where it applies.
9 minute read Site validation · UncertaintyWhat NSA and site VSWR are, where the chamber's deviation enters the CISPR 16-4-2 budget as a triangular term, and how much a validation result better than the tolerance is worth in the expanded uncertainty.
10 minute read Site validation · StandardsCISPR 16-1-4 added NSIL, a site validation for 9 kHz to 30 MHz with a pair of loop antennas. The method, the geometry, who it applies to, and a measured result from a semi-anechoic chamber at 3 m.
9 minute read Calibration · StandardsThe 2025 edition adds a second-peak limit to the discharge current, calibrates the air discharge tip for the first time and redraws the calibration set-up with a dimensioned ground plane. What each change means for a certificate.
9 minute read Test methods · CalibrationThe CISPR-average detector and a spectrum analyser's average agree on a steady signal and part company on everything else. How they differ, and which one a CISPR or FCC average limit is written for.
8 minute read CalibrationA sine-wave calibration cannot show CISPR 16-1-1 compliance. What Annex K and Table K.1 actually require, which rows a spectrum analyser calibration can never cover, and what to look for on the certificate.
9 minute read Calibration · Test methodsA three-phase LISN can be used for a single-phase product, but a three-line CDN cannot be used with two lines. The opposite answers come from how CISPR 16-1-2 and IEC 61000-4-6 define impedance.
6 minute readSend it to us. If it is one we hear often, it becomes the next note.
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