EWIS Yule Log
With 2020 drawing to a close, we wanted to finish our busiest year in our lab with one more experiment. We hope that you all enjoy Lectromec’s version of the traditional yule log. Read more
Blog
Impacts of Sanitizing Fluids on Wiring
Key Takeaways COVID-19 has resulted in a higher concentration of sanitizing products being used on aircraft. The FAA has released special airworthiness information bulletins highlighting the concerns with the application of sanitizers on aircraft. An internal Lectromec study was performed to determine effects of sanitizing fluids on wires. Wire and cable are exposed to a […] Read more
New Means to Assess Corrosion Susceptibility
Low outgassing materials are critical for space applications. As one might imagine, a small, enclosed space with outgassing materials is not an ideal environment. To that end, space system developers have always sought insulation constructions with low outgassing properties. In past articles, Lectromec has covered the developments of the methods and materials used to reduce outgassing. Here, we examine the latest testing techniques for these materials. Read more
WPAFB Wire Study
Key Takeaways Publicly available recorded data compares many of the commonly used aerospace wire types. Corona extinction and inception voltages of cables decrease drastically with an increase of elevation. Many insulation types display a significant decrease in mechanical durability at increased temperatures. Modern wires of the AS22759 family are incapable of stopping 270 voltage DC […] Read more
IEEE 1584-Arc Standard
Key Takeaways IEEE 1584 provides a basis and a model for arc flash protection and necessary safe separation distance. The standard targeted the necessary calculations for power distribution. While there is some overlap with the aerospace industry wiring system requirements, the model’s range inhibits its use for aircraft. Research down an unfamiliar path often includes […] Read more
Conductor Resistance ASTM B193
The measurement of resistance seems to be a trivial task. Hook up a standard handheld multimeter with two probes and attach the probes to either side of the device or component that you want to measure. For the most part, this process works well. More correctly, for devices with resistances between 2 Ohms and 1M Ohm, this is a good technique, however, once the resistance values get really high or really low, the process becomes a little more complicated. While the basic physics remains the same (Voltage = Current * Resistance), getting the setup to correctly measure the component requires attention to detail. Read more
AS4372 – Building a Wire/Cable Specification
While it is possible to start from scratch and develop an independent set of tests and performance requirements, there are existing standards that can be used to expedite the process. Read more
Selection of Zones for Degradation Testing
Maintenance zones within an aircraft are not homogeneous. They vary from the extreme Aircraft areas within the aircraft (engines) to more benign areas (inside pressure and temperature-controlled areas). And because of this, the components within each of these zones will age at different rates. Naturally, different components are selected for each of these zones; those components better able to handle the severe environments are installed in those environments, and lower requirements are placed on those parts installed in benign environments. Read more
Solder Sleeves and Splicing in Shields
Shielded cables are necessary. They provide necessary EMI protection to ensure signal fidelity, and in some cables, such as coaxial cables, the shield is integral for signal transmission. Trying to use only non-shielded cables in any modern design would encounter such a significant impact on performance, it may not be possible except for a limited number of applications.
Because of this need for shielded cables, there is a wide range of components and supporting technologies to ensure proper use and reliable transmission of data. One of these technologies is a device to help with shield termination.
Read moreDielectric Constant
There are some properties that are taken for granted with wires and cables until they are needed for precision applications. A conductor’s conductivity is assumed until the impact of a voltage drop or heating must be determined. In the same way, a cable’s dielectric constant is uninteresting until the integrity of high-frequency signals becomes critical.
This last property (dielectric constant), is important not only for cable insulations but also for a wide range of applications.
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