INTRODUCTION Radiated emissions testing is only one part of emissions testing. CISPR 32, the document that lays out limits and methods of measurement for emissions (radiated and conducted) for Information Technology Equipment (ITE), broadcast receivers and multimedia equipment is 120 pages in length. ANSI C63.4 deals with only the testing part (limits are contained in a … [Read more...]
About the Author
Ghery Pettit
Ghery S. Pettit, NCE is the President of Pettit EMC Consulting LLC. He is a graduate of Washington State University and is a Life Senior Member of the IEEE. He has worked in the EMC world for the past 42 years in positions with the US Navy, Martin Marietta Denver Aerospace, Tandem Computers, Intel Corporation and now as an independent consultant. Mr. Pettit is a past President of the IEEE EMC Society and currently serves as Chair of CISPR Subcommittee I, which is responsible for emissions and immunity standards for broadcast receivers, ITE and multimedia equipment. He has designed and operated EMC laboratories, provided EMC analysis, design, troubleshooting and testing support for a variety of projects and contributed to various EMC standards such as ANSI C63.4, CISPR 22, CISPR 24, CISPR 32 and CISPR 35. Ghery may be reached at [email protected] or at (360) 790-9672.
Summary of Military and Aerospace EMC Tests
INTRODUCTION Military and aerospace EMC tests cover a wide range of products. While the standards, including limits and test methods may differ, all EMC test standards have a few things in common. The most basic are the limits for emissions and the types and levels of susceptibility testing. Emissions tests (and their associated limits) are put in place for military and … [Read more...]
Summary of Commercial EMC Tests
Introduction Commercial EMC tests cover a wide range of products. These include the obvious ones like computers and their peripherals but also cover household appliances, electric tools, and a wide variety of other products. While the standards, including limits and test methods, may differ, all EMC test standards have a few things in common. The most basic are the limits for … [Read more...]
A Short History Of A Few ITEM Issues
1977 My first issue of ITEM (Interference Technology Engineers Master) is from 1977. Was this the first issue of ITEM? No, it was not. However, it was my first issue. Why? I got my start in EMC in 1976 while working for the US Navy and was too late to get the 1976 issue. I graduated from college in 1975 and moved from Code 2330 (Nuclear Controls Engineering Division) at Mare … [Read more...]
HOW TO PREPARE YOUR PRODUCT AND YOURSELF FOR EMC TESTING
INTRODUCTION Your product has EMC requirements. You have to test it to demonstrate compliance with those requirements. How do you prepare for the test? How do you prepare your product for the test? These are two different areas that need preparation before you go to the lab. Let’s look at them, one at a time. HOW DO YOU PREPARE FOR THE TEST? First, you need to … [Read more...]
What is EMC?
Introduction This article will serve as an introduction to the topic. It is aimed at the people who have been told by their management, “You are now my EMC person. Go figure out what it is and how we must deal with it!” It will not be an all-encompassing treatment of the subject, but it will provide the reader with a start and some ideas of where to go for more … [Read more...]
New and Proposed Changes to CISPR SC I Standards
Are you familiar with CISPR 32 and CISPR 35? CISPR 32 was originally published in 2012, followed by a pair of corrigenda and then the 2nd edition was published in 2015. CISPR 32 replaced CISPR 13 (Broadcast receivers emissions) and CISPR 22 (ITE emissions), both of which were withdrawn by the IEC on March 5, 2017. In the EU CISPR 32 is published as EN 55032 and it has … [Read more...]
EMC Laboratory Selection Audit Items
Introduction This blog will provide the reader with an introduction to some of the items that need to be looked at when auditing an EMC laboratory with an eye to placing them on your company’s approved lab list. This is not an in-depth look at each item but is based on my experiences auditing laboratories (both in-house and 3rd party) over a number of years. Key … [Read more...]
Does the Number of Bypass Capacitors for a Chip Matter?
How do you decide on the size of a bypass capacitor (or capacitors) for your project? Do you need multiple capacitors to bypass a specific chip? Are multiple value capacitors important for a given use? Do you subscribe to the old Wife’s Tail about having a couple capacitors a couple orders of magnitude different in value in parallel? Here is one take on the subject for you … [Read more...]
Emissions Test Facility – OATS vs SAC?
You’ve been tasked by management to build a new, from scratch, EMC test facility. Among other items, you need to decide between an Open Area Test Site (OATS) or an RF Semi-Anechoic Chamber (SAC). How do you decide? To someone who has been there, done that, the choice is clear, but what are some factors that might sway the decision one way or the other? Design of an … [Read more...]
