Electronics Protection - September/October 2013 - (Page 9)

Feature Reliability Data The gasket holder with the DUT in place can be removed and subjected to accelerated aging to collect reliability data. The SE data for a gasket before and after 3,000 hours of 85 percent humidity and 85°C and maximum operating temperature (160°C) aging is shown in Figure 3. The SE of a control sample was recorded, and then it was subjected to accelerated aging and data after aging was captured. TEM Cell is the only method that maintains joint surfaces during aging. Samples for radiated enclosure and transfer impedance measurements are aged un-flanged. SE measurements with industry standard methods are presented in following section to equipto earthquake 2010:Layout 1 3/22/10 10:13 AM Page 1 validate TEM cell reliability data. Please see Laird on page 15 Figure 2. Noise Floor and Reference Measurements Gasket SE Measurement Excitation and measurement is performed by the TEM structures mounted in the GTE. The measurement is made by taking the ratio of received energy to the excitation energy. In particular, the transverse field produced by one of the TEM horns is incident on the slider, which also contains the DUT. Depending on the quality of contact between the gasket that is placed between the slider and the floor of the enclosure, a measure of the gasket shielding effectiveness is determined by how much of the transverse field is transmitted to other TEM structure. The SE is given in equation (1), where Einc is the incident wave, and Etr is the transmitted electromagnetic wave. The enclosure is a resonant cavity and TE and TM mode artefacts are significant and limit the useful frequency range to 2 GHz, though there may be ways to extend this in future. Protection from earthquakes and other threats When the ground starts to shake and things are being torn apart the last thing you want to worry about is the shock and vibration resistance of your system’s enclosure. O ur line of “Heavy Duty” modular, seismic hardened electronic cabinets meet NEBS seismic requirements of Telecordia GR-63 CORE through Zone 4, the most severe test. Without changing cabinet lines or your designs, Heavy Duty also meets requirements for: • Mil-Spec 810 and 901 • Shock and vibration • Mil-Std 461, IEEE 299, NSA -94-106 • EMI/RFI, FCC/VDE • Metric and more Documented proof and information to properly load our cabinets for your own seismic tests available on request. For personal assistance, or a catalog, contact us today. The shielding effectiveness of a gasket is determined by subtracting the measured insertion loss with the gasket in place from the reference measurement by utilizing formula (2). A 25 percent constant compression is applied uniformly for SE measurements on the DUT. The test gasket initial SE is captured and the DUT removed for accelerated aging without altering the initial compression. Figure 3. Reliability data of a test gasket with TEM Cell 800-204-7225 • 630-859-7840 • www.equiptoelec.com sales@equiptoelec.com • Aurora, IL 60506 ISO 9001:2008 RoHs Compliant Proven tough during the Chilean earthquakes September/October 2013 www.ElectronicsProtectionMagazine.com 9 http://www.equiptoelec.com http://www.equiptoelec.com http://www.ElectronicsProtectionMagazine.com

Table of Contents for the Digital Edition of Electronics Protection - September/October 2013

Geist Unveils Rapid Deployment Data Center Environmental Monitoring System
Enabling Effective Thermal Management with DCIM
Predicting Gasket Performance: SE Measurements with a TEM Cell to Study Gasket Reliability
Rack Containment 101
The Nine Core Elements of DCIM
Using Electronic Locking Solutions to Secure Enclosures and Meet Storage Compliance Needs
Hammond’s HJ Series Ticks All the Boxes
Rogers Introduces Poron SlimGrip Foam
Ferrite Suppressors Clear Interference
Fujipoly Thermal Sheets are a Cooling Influence on LED Lighting
GE Introduces TLE Series UPS Platform
Gore PolyVent XL Improves Reliability of Large Outdoor Enclosures
IMI Sensors Launches Linear Adjust Mechanical Vibration Switch
Industry News
Calendar of Events
Five Ways to Realize Server Room Profitability

Electronics Protection - September/October 2013