Down and Dirty
Industrial environments create unique obstacles for IP video surveillance equipment
- By Willem Ryan, Cheryl Bard
- Aug 06, 2009
Heat, dust, flammable gases and poor lighting are just a few of the
challenges that IP video surveillance equipment must overcome.
These conditions can render some video devices ineffective or
cause a hazardous situation when mixed with video products that
are not equipped with the features designed for safe operation in
harsh locations. As a result, selecting the right equipment for an industrial facility is
extremely important to the success of a video system.
Lighting the Way
Adequate illumination is essential to acquiring useful images, observing activity and
identifying specific actions, objects or persons. However, lighting at many industrial
sites is often widely dispersed with high-intensity lamps that create overexposed "hot
spots" against a backdrop of darkness.
While day/night cameras are sufficient for many types of industrial facilities, some
organizations require a higher level of image quality at night. In certain industrial
environments, especially critical infrastructure facilities, it is important to obtain
high-quality images 24 hours a day.
For example, high-risk chemical facilities implementing stringent site security
plans as part of the Department of Homeland Security's Chemical Facility Anti-terrorism
Standards may need to add active infrared illumination to ensure a clearer picture
of sensitive areas.
Active-infrared illumination is defined as light that lies in the wavelength region of
700 to 1,000 nanometers. Its wavelength is just beyond the visible region of 400 to 700
nm, making it invisible to the human eye. The addition of active-infrared, day/night IP
cameras helps form clearer images.
An IR-sensitive day/night camera can be combined with an infrared illuminator to
produce video that more closely resembles crisp, monochrome images captured during
daylight hours. For the best results, look for IP cameras that deliver a virtually continuous
variation of gray levels. Achieved with cameras that offer 15- or 20-bit digital
image processing, this capability is important for exceptionally accurate picture reproduction. Also, choose illuminators that
eliminate hot spots and underexposure by
lighting both the foreground and background
of an entire scene.
As active-infrared light helps produce
clearer images with less noise, it
also greatly affects bandwidth in IP
video installations. Snowy or grainy
images interfere with the compression
algorithms used in today's IP cameras.
Consequently, nighttime images without
active infrared are less compressed and
produce larger file sizes and bit rates—
the amount of space per second required
to transmit data on the network. Infrared
illumination can decrease bit rates by
70 to 90 percent, helping to improve
network performance and reduce
storage requirements.
Infrared illumination also helps to
improve the nighttime performance of
video content analytics. Providing an
added layer of protection for sensitive
industrial facilities, such as critical infrastructure
sites, video content analytics
can help alert system operators to security
risks, such as a perimeter breach or loitering.
As infrared illumination produces
clearer images that are more evenly illuminated,
event detection and improved
situational awareness through analytics
are more easily achieved.
Tough Housings for Tough Environments
While image quality is usually one of
the foremost concerns with an IP video
surveillance system, choosing the appropriate
housing for a camera is almost
equally as important at an industrial
facility. Housings help protect the cameras
to ensure a long-lasting and durable
surveillance system and can ensure the
camera does not inadvertently create an
unsafe environment in a hazardous
location. Camera housings are rated
or certified to indicate the degree of
protection provided by the enclosure.
Ingress protection codes provide
insight into how the housing will stand
up to solids and liquids often encountered
in industrial environments. The
first number of the code indicates the
ability to withstand ingress of solid foreign
objects, such as dust. This number
ranges from 0, signifying no special protection,
to 6, which represents total
protection against dust.
The second number indicates protection
of internal equipment against
harmful ingress of liquids, such as
water. This number ranges from 0, for
no protection, to 8, signifying protection
against long periods of immersion
under pressure.
The National Electrical Manufacturers
Association also publishes rating specification
standards in reference to the operating
environments for a variety of electrical
devices. NEMA enclosures meet standards
for protection of the electrical equipment
installed within them. Possible ratings
include NEMA 1, 3R, 4, 4X and 12. A
NEMA-1-rated enclosure is typically used
for protecting controls and terminations
from objects and personnel, while a
NEMA-12-rated enclosure is designed to
prevent the ingress of dust, water and oil.
Class I, Division I certifications
ensure housings are safe for use in locations
where ignitable concentrations of flammable gases or liquid vapors are present during normal operation. Hazardous
gases and vapors include acetylene, hydrogen, ethylene and methane. Class II certification
indicates the product is safe for operation in areas with ignitable concentrations
of combustible dusts, such as carbon-based or agricultural dusts. Some environments
where these materials and vapors are commonly present include chemical factories,
petroleum refineries, and coal and carbon processing plants.
Manufacturers typically refer to these certified housings as "explosion protected,"
which means the housing will withstand an internal explosion of a gas or vapor without
rupture and without causing the ignition of an external gas or vapor surrounding
the enclosure.
A Critical Choice
Rohrer's Quarry Inc. in Lititz, Pa., does not require explosion-protected
housings, but this provider of concrete, stone and related products does need to
ensure its IP cameras are protected from the dust and water that are part of its
everyday operations.
When Rohrer's Quarry erected its new ready-mix concrete plant last year, it selected
Bosch FlexiDome IP Day/Night cameras as part of a surveillance system designed
to oversee operations—an important component of the company's efforts to provide a
safe and stable workplace for employees.
The FlexiDome cameras installed at the plant have a clear polycarbonate dome bubble
with a UV-blocking anti-scratch coating and can operate in temperatures from 14
to 104 degrees Fahrenheit and in 20 to 80 percent relative humidity. The cameras also
are IP-54 rated to prevent harmful deposits of dust and protect against water sprayed
from all directions. The rating ensures protection from conditions that are common
within a concrete-mixing plant. The NEMA-3R rating also ensures protection against
falling sleet and snow and external formation of ice on the enclosure—important for
products installed outdoors in the Northeast.
The 11-camera surveillance system captures video of the most critical points inside
the plant, which features three 200-ton cement silos, six compartments containing 340
tons of aggregate and a 430-foot vertical curve conveyer. The system shows crisp
images and a high level of detail of areas where conveyer belts unload onto other belts
and where the concrete contents are poured into the mixer.
"We require clear images from reliable cameras that can withstand the dust and heat
within the plant," said Travis Rohrer, a co-owner of Rohrer's Quarry.
Outside the plant, cameras are positioned to view the location where concrete is
discharged into the Quarry's 20-truck fleet of transit mixers. A camera installed on
the roof of the building that houses the plant also provides surveillance of the
surrounding property.
Overall, the IP video surveillance solution helps oversee plant operations—improving
efficiency by allowing the plant operator to monitor several areas that are essential
for proper mixing of concrete and for discharging it into awaiting trucks.
The cameras stream video for 24-hour observation to Bosch's VIDOS video management
system, which the operator uses to control cameras throughout the facility.
Using the VIDOS monitor wall application, video from the cameras is displayed in real
time on two LCD flat-panel monitors in the plant's central control room.
From the control room, the plant operator and dispatcher can see trucks in the
staging area waiting to be loaded and can keep track of vehicles that enter and exit
the quarry for enhanced security. They also can view areas that would otherwise be
inaccessible from the control room, allowing oversight of locations where aggregate
and sand are introduced into the cement and helping the dispatcher position trucks
under the mixer's discharge chute to achieve greater accuracy when loading them.
"The cameras have been invaluable in what they allow us to see throughout the
entire plant," Rohrer said. "They are a great tool
in helping us do our jobs better and faster."