Adding Armor to Security Systems
a&s International | Date:
As video surveillance systems find their way into new markets and applications, it is important to protect increasingly sophisticated cameras from not only good old vandalism, but also harsh weather conditions and environments.
Weather and environmental stress that can disrupt service in the surveillance system must be evaluated and accounted for. Enclosures are to cameras what shells are to turtles, except much more durable and versatile. Different environments will require different considerations, as one will definitely not fit all.
Recent trends in camera enclosures include smaller form factors, customized designs, increased tolerance to extreme temperatures and more offerings that include both the camera and lens, said Barry Lawson, Global Marketing Manager for Schneider Electric. “Advanced materials, such as plastics that are resistant to any type of challenging environment, are being used in camera enclosures.”
Developments in camera housings are leading to new, cost-effective, indoor plastic camera enclosures and vandal-resistant aluminum and polycarbonate outdoor camera enclosures,Marketing and Product Management for Arecont Vision. “Also becoming more available are all-in-one designs that include the camera, mounting hardware and IP66 enclosure. In general, cameras are reducing in size yet provide higher resolutions.”
Fine-tuning materials to eliminate any form of rust or oxidation on the exterior of the housing ensures longevity of the housing itself, as well as its aesthetics, said William Ferris, Engineering Department of Dotworkz Systems. “In addition, the use of different types of vandaland gunshot-resistant materials in outdoor housings allows for more design flexibility." Cameras of all types can be placed closer to the action, without the risk of damage.
Some types of housings see new developments more rapidly than others, but it has more to do with the standards than anything else, said Kostas Mellos, Commercial Leader for Video and Transmission, Interlogix (a UTC Fire & Security company). “Explosion-proof housings that are intrinsically safe against sparks are governed by specific NEMA and UL conditions. They must adhere to the conditions specified and do not see rapid changes.”
There are mainly three types of housings targeted for adverse environments, Mellos said. “There are ones that withstand atmospheric conditions, such as extreme heat and cold; explosion-proof; and pressurized bubbles.” As environmental conditions vary widely from project to project, the characteristics of the site must be accounted for differently and accordingly.
For example, electronics have specified operating temperatures; when mounting an outdoor, vandalproof dome camera outside a building in a very cold region, you must have at least heaters in there to ensure the electronics do not malfunction, Mellos continued. “Plastics have come a long way and some can deal with this type of environment, but you still can't use them in explosion-proof settings. They simply do not conform to the specifications that are needed.”
For projects that face corrosion and extreme conditions, the enclosure can deteriorate quickly and cause the camera view to be compromised, the housing mounts to be altered or the wires to be exposed, said Lem Blanco, Engineering Manager at CPS Security. “All these may lead to countless issues, such as falling housings or loss of video.”
Natural factors, such as insect infestation, temperature and climate, salt, humidity and wind, must be evaluated, Blanco continued. “For example, airports need to address the constant jarring movements caused by landing planes, while oceanfront projects such as seaports must factor sea breeze and salt water into the equation.”
Protecting the inside of the housing is just as important, through added pressure using dry nitrogen or other types of gas, Mellos said. “When the inside pressure is greater than the outside pressure, outside elements can't enter the inside, effectively protecting it from harm.”
Cable management is another issue. How the housing manages the cables that come out of the camera or heater is critical in some cases. In the UL standard for explosionproof environments, a certain type of conduit is required to avoid any risk of sparks within that space.
System requirements such as power supply also need to be examined. For truly extreme locations, directly powering camera housings ensures that the cameras are set up for long-term reliability, Ferris said. “PoE injectors can create a point of failure in the long term. Furthermore, many professionalgrade brands of video hardware have higher power requirements than PoE can provide. For example, a high-end extreme cold weather system can easily require 65 watts just for the heating system, exceeding current PoE limits.”
Products that incorporate heaters/ blowers or IR illuminators currently require separate auxiliary AC or DC power sources, but there are companies developing technology to support power for these accessories via PoE, Calderon said. “Gaskets and fillings are provided to facilitate proper installation and protection from outside elements. When properly installed, they maintain protection for the auxiliary power wiring as well as the PoE/ data cable.”
Maintenance should not be overlooked, either. For a high-performance, 360-degree, HD camera housing that oversees high-value assets, performance can quickly deteriorate due t o dus t and salt buildup on the lower lens.
Commonly it only takes a few weeks before cleaning maintenance is required, Ferris said. “Properly scheduling maintenance and purchasing the needed cleaning tools are often overlooked. Products designed to safely clean all shapes of exterior lenses and camera housings from ground level are available.”
The biggest issue for pressurized housings, or housings that are intrinsically safe such as explosionproof housings, is maintenance. A pressurized dome in an environment with a lot of dust will need the typical cleaning, wiping down and pressure cleaning as any other appliance, Mellos said. “However, the internals do not necessarily need maintenance. If it's pressurized, the camera tends to be more stable than its non-pressurized counterparts since no outside elements can find their way into the components. If there is something wrong with the camera, or if you need to do something to the camera itself, you need to depressurize the housing, which is not a big deal, but you need to have the proper tools.”
Frequent maintenance is necessary for really adverse environments. For mills or furnaces, it is very possible that the cameras themselves will not last long, due to the sheer heat generated, no matter how much you try to cool the housing, Mellos said. Factors to keep in mind differ per location or need, Blanco added, but one thing to always be on the lookout for is quality.