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."