| If you are about to purchase wire or cable for | | | | Disadvantages: Not effective above audio |
| the first time, or even if you have purchased it in | | | | frequency range |
| the past, you may find the task daunting. After | | | | Combination Shields: |
| all, most distributors stock thousands of wire and | | | | Uses: Video, CATV, MATV, networking, computer |
| cable products. Your application may require | | | | I/O cables |
| ribbon cable, but which specific ribbon cable should | | | | Advantages: 100% foil coverage, strong and low |
| you buy? Having choices is important, but with | | | | resistance |
| so many choices, decision-making can become | | | | Disadvantages: Higher cost than other shields |
| overwhelming. | | | | Chemical Resistance |
| Do you know what questions to ask? Before | | | | An engineer will tell you that electrical cables |
| beginning a search, equip yourself with the right | | | | possess various levels of chemical resistance, but |
| knowledge. Background information combined | | | | there may be more to it. You should know |
| with basic preparation can give you some | | | | which chemicals could present a potential problem |
| command during the buying process. In the | | | | in the entire lifespan of your cable. Also, consider |
| article, “Specifying High-Performance Cables: | | | | that oils and corrosive chemical vapors or liquids |
| The Devil Is In The Details,” by Alpha Wire | | | | could potentially enter into the cable connections. |
| Company, they evaluate four main issues to be | | | | Any type of chemical intrusion could lead to cable |
| considered. These are cable shielding, flexibility, | | | | failure. You might need to add additional sealing |
| chemical resistance, and temperature range. | | | | to prevent moisture permeation. |
| Shielding | | | | Temperature |
| When purchasing cable, be sure to explore cable | | | | Temperature range is another essential factor in |
| shielding. Shielding ensures that the electrical | | | | the mix of things. What temperatures will your |
| process runs smoothly. An engineer will tell you | | | | cable need to withstand to be effective? You |
| shielding minimizes problems of signal exit or | | | | may find that a cable possesses all the necessary |
| entrance caused by interference. Types offered | | | | electrical features required for extreme |
| include braid, foil, spiral, or a combination braid/foil | | | | temperatures, but will it be able to adapt to the |
| shield. Each type has advantages and | | | | physical demands associated with that |
| disadvantages: | | | | temperature? |
| Foil Shields: | | | | Flexibility & Flex |
| Uses: CATV, MATV, Video, computer I/O cables | | | | A flexible cable can make installation and |
| Advantages: 100% cable coverage, low weight | | | | troubleshooting much easier. However, did you |
| and low cost | | | | know that “flexing” is a different issue |
| Disadvantages: High DC resistance and lower | | | | that needs to be addressed? Due to the nature |
| mechanical strength | | | | of many manufacturing applications, cables may |
| Braid Shields: | | | | encounter constant flexing. Particular cables are |
| Uses: Computers to terminate interconnect for | | | | built better for this than others. |
| process or control applications | | | | Conclusion |
| Advantages: Great structural integrity, flexibility | | | | There is more to finding the ideal cable than |
| and flex life | | | | meets the eye. Don’t be intimidated by |
| Disadvantages: Does not provide full coverage, | | | | choices. A cable exists for just about every |
| heavy | | | | environment and application if you know what to |
| Spiral Shield: | | | | look for. Spend some time asking the right |
| Uses: Microphone, audio cables and retractile cords | | | | questions and consider every angle. |
| Advantages: Great flexibility and flex life | | | | |