Released in May of 2011, GR-1089-CORE Issue 6 Electromagnetic Compatibility (EMC) and Electrical Safety requirements for Network Telecommunications Equipment has undergone a number of technical changes. We look at its substantial modifications and the potential impact on previously certified products. Click here for the full article written by NTS EMI/EMC Engineering Manager Jeffrey Viel for InCompliance Magazine.
Critical EMC Concepts for Meeting Radiated Immunity Requirements Seminar
An examination and discussion of the nature of external EMC influences, product enclosure design and physical artifacts of the chassis i.e. shielding and various design compromises, effects of system cabling and interconnection, external interface port design and RF referencing of supporting circuitry, and resident internal design structures that would assist/weaken external interface ports. Includes coverage of troubleshooting techniques to quickly characterize the specific issue, isolating the circuit function affected, identify point(s) of entry and transmission mechanism(s), and determining mode of propagation along with effective mitigation techniques. Visit the events page for more information and to register.
NTS Test Systems Engineering Division to Develop Automated Test Equipment (ATE) for the Boeing 777 Program
Calabasas, CA (July 7, 2010)…National Technical Systems Inc. (NASDAQ: NTSC) (NTS), a leading provider of engineering services, announced today that its Test Systems Engineering Division has been selected by The Boeing Company to provide Automated Test Equipment (ATE) systems in support of its 777 Program. The ATE systems will perform tests on 777 systems, avionics and engines using automation to quickly perform measurements and evaluate the test results.
NTS is pleased to announce that we’ll be exhibiting at the upcoming Farnborough International Air show to be held from July 19 to 25, 2010 in Farnborough, UK. The Air Show at Farnborough is the premier global showcase for everything that is part of the aerospace industry. Held once every two years, the 2008 Air Show attracted nearly 300,000 visitors. Exhibitors include nearly all the world’s aircraft manufacturers including Boeing and Airbus, as well as manufacturers of aircraft components and services. More information on the show can be found on their website. NTS will be in stand H2/B35.
The M82 Percussion Primer is employed to initiate the propelling charges of separately loaded artillery weapon systems. Unique to the 155 mm M777 Light Weight Howitzer weapon system design is the use of a magazine assembly mounted in the breach mechanism of the howitzer in which ten M82 percussion primers are loaded. This design allows the primers to experience shock loadings associated with multiple howitzer firings. To address concerns as to the potential impact this shock environment may have on the sensitivity of the percussion primers in the Marine Corps inventory, the Expeditionary Systems Evaluation Division of NSWC Crane, in concert with National Technical Systems (NTS) Ordnance Sciences department, conducted tests to characterize the pyrotechnic shock imparted to the magazine assembly of the M777 howitzer during weapon system firings and then used this data to develop a series of laboratory tests to characterize changes in the sensitivity of the M82 Percussion Primer as a result of multiple exposures to these shock environments. This work was done in support of the Program Manager for Ammunition of the Marine Corps System Command service life accelerated age testing program. The paper “Pyrotechnic Shock Loading of the M82 Percussion Primer in the M777 Light Weight Howitzer Magazine Assembly” will be presented at the NDIA Joint Armaments Conference being held in Dallas, TX, May 17 through 20, 2010. NTS will be exhibiting in booth 521.
by Vesta I. Bateman, Chair, IEST Working Group DTE032
The IEST Recommended Practice on pyroshock testing has been revised and updated to reflect advances in the art of pyroshock testing and to address common problems related to data accuracy in the pyroshock community. The key changes to IEST-RP-DTE032: Pyroshock Testing Techniques are described here.
New definitions for near-field pyroshock, mid-field pyroshock, and far-field pyroshock adopted by IEST-RP-DTE032.2 are consistent with the definitions given in MIL-STD-810G, Method 517, as shown in the table and the spectra definitions below. The definitions and table values are quantified in terms of shock response spectra (SRS). The SRS, with an appropriate damping value, is the most widely used tool to analyze pyroshock data and is calculated using acceleration measurements near components and subsystems that must be qualified separately. The Jet Propulsion Laboratory will be revising NASA-STD-7003 during the coming year, and the current NASA values for near-field, mid-field, and far-field pyroshock are also shown in the table.
A near-field pyroshock test requires frequency control up to and above 10 kHz for amplitudes greater than 10,000 g. A pyrotechnically excited simulation technique is usually appropriate, although in some cases a mechanically excited simulation technique may be used.
A mid-field pyroshock test requires frequency control from 3 kHz to 10 kHz for amplitudes less than 10,000 g. A mechanically excited simulation technique other than shaker shock is usually required.
A far-field pyroshock test requires frequency control no higher than 3 kHz for amplitudes less than 1,000 g. A shaker shock or a mechanically excited simulation technique is appropriate.
via: Pyroshock Testing, Institute of Environmental Sciences and Technology
The FCC has announced that it has currently halted issuing new and any Class 2 Permissive Change certifications that require a DFS evaluation for Master devices until further notice. The National Telecommunications and Information Administration (NTIA) is currently investigating interference with UNII Master Devices and the FCC. Dynamic Frequency Selection (DFS), a mechanism to allow unlicensed devices to share spectrum with existing radar systems is mandated in the 5250-5350 and 5470-5725 MHz UNII bands.
Elliott Laboratories continues to test Master devices and is currently awaiting on further updates from the FCC. For more information, please contact us via email at info@elliottlabs.com or at 408-245-7800.
The Federal Communications Commission (FCC) issued a $7,000 forfeiture against Sennheiser Electronic Corporation for willful and repeated violation of Section 302(b) of the Communications Act of 1934; the apparent violation involves Sennheiser’s marketing of unauthorized radio frequency devices.
In July 2008, the Enforcement Bureau Spectrum Enforcement Division began an investigation into Sennheiser’s marketing of wireless microphones. In a letter of inquiry dated August 15, 2008, the Division instructed Sennheiser to provide specific information regarding the manufacture, marketing, and the certification status of the wireless microphone systems it sells. In its September 15, 2008, response to the letter of inquiry, Sennheiser indicates that, while preparing its response, it discovered that one of its wireless microphones did not have a valid certification.
Readers can view the FCC notice by clicking here.
Manufacturers of Information Technology Equipment (ITE) intended for sale in the European Union should take note of some important changes that are slated to go into effect with regard to their EMC testing requirements under emissions standard EN 55022:2006.
In November 2008 the European Union’s Official Journal (OJ) published lists of standards for the Electromagnetic Compatibility (EMC) Directive and Radio and Telecommunications Terminal Equipment Directive (R&TTED). Both lists include references to EN 55022:2006 and its amendment A1, released in 2007.
EN 55022:2006 will supersede EN 55022;1998 and become the requirement for Information Technology Equipment (ITE) sold into the European Union after October 1st 20091 , with the requirements of Amendment A1:2007 coming into force one year later on October 1st 2010. What are the differences between the 1998 and 2006 versions of the standard and what new requirements will be introduced by A1:2007? Let’s begin by reviewing the history of CISPR 22 from 1997 onwards. International Standard CISPR 22 is the basis for not only EN 55022 but also for many of the other national versions of standards for ITE.
To read the rest of the article, please click here.
Elliott Laboratories is currently equipped to conduct the EU free space testing above 1 GHz per EN55022:2006+ A1 and/or CISPR 22:2005 + A1 in all chambers at our Fremont facility. For more information about how this change affects your products or for a price quote to test your product, please contact us at info@elliottlabs.com or call at 408-245-7800.
