The Important of "Potting" Electronic Access Control Equipment

Potting protects against water and moisture, and insulates key components electronically.

Scott Lindley is general manager of Farpointe Data, and a 25-year veteran of the contactless card access industry.
Scott Lindley is general manager of Farpointe Data, and a 25-year veteran of the contactless card access industry.
SDM

No longer do security providers face the problems that used to be inherent with mechanical hardware. Moving parts become fatigued. Electric products don't wear out. But, today, with electronic, solid-state computer peripherals, they nonetheless still have their issues, albeit new ones. Moisture, insulation and vibration, among other variables, can cause false alarms as well as damaged results and other failures.

The big question for manufacturers of security equipment is how can they eliminate costly repairs or replacements for their end users and help their integrators avoid annoying service calls.

Potting is, simply, the practice of covering a component with a resin to guard against potential environmental threats. Potting protects against water and moisture, and insulates key components electronically. Potting also defends sensitive printed circuit boards and other critical components from thermal and physical shock, and chemical attack and tampering, and it serves as a shield that protects intellectual property and consumer information. Using potting is recommended for guarding sensitive electronic components from impact, vibration and loose wires.

Although typically black, the potting material can be created in any color. Many companies prefer a color that will help them drive brand imaging.

And today’s potting is not the nasty material from the past. Potting substances are normally RoHS (Restriction of Hazardous Substances) compliant and do not contain any known carcinogenic components.

When we pot a plant, we steady and protect the vulnerable root system. We fill the pot with soil and nutrients to hold it in place. When it comes to electrical components, we do much the same thing. Electronic components are also "potted" in suitable enclosures and with appropriate compounds that not only protect against shock and vibration, but also against the formation of moisture. In this scenario, vulnerable electronic parts are kept from any kind of harm.

In the potting process, an electronic assembly is placed inside a mold (i.e. the pot) which is then filled with an insulating liquid compound that hardens, permanently protecting the assembly. The mold becomes part of the finished article and may provide shielding or heat dissipating functions in addition to acting as a mold.

There are other solutions that can get the weather-resistance job done, such as conformal coating, which applies a thin protective coating to an entire circuit board. But, depending on the application, they may be less cost-efficient than potting, and neither conformal coating nor full enclosures can address the issue of trapped hot air and the damages it can do. Thus, potting is often the best and most cost-efficient solution.

Among the advantages of "potting" electronics is that it is a very flexible solution. We can apply potting only to high-risk parts and components, or to complete boards and assemblies. Conductivity, electrical and thermal isolation and protection against various environmental conditions and threats can all be met by the many available potting materials.

What does all this mean to security access control hardware managers? Only install readers that are fully potted, that do not allow access to the reader’s internal electronics from the unsecured side of the buildingAn immediate upgrade is recommended for readers that fail to meet this standard.

Such vandal-resistant contactless card readers are ideal for installations where more durability is required than with a standard reader. They are becoming big hits at schools, universities, correctional institutions, housing authorities, factories, hospitals and other locales where RFID proximity and smart card readers can take a beating.

The impact of the added vandal resistance that potting provides cannot be underestimated. Essentially, potting helps in making a reader — especially one installed on the unprotected side of a door — more tamper-resistant.

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