April 2004                                                                                                                                                

PUTTING SENSORS TO WORK

Infrared Thermography
for Remote Condition Monitoring and Control

Optical surveillance systems can work the night shift too, with the addition of IR cameras. This Web-enabled system watches for intruders and other anomalies and either notifies the appropriate personnel or decides on its own what action to take.

Corey Maple, MiniMax Corp.
Leonard Phillips, FLIR Systems Inc.

Incidents of sabotage near Anderson, CA, and Klamath Falls, OR, and the subsequent 2003 East Coast blackout have served as disquieting reminders that the country’s electric transmission and distribution infrastructure is vulnerable to both hostile activities and accidents. Short of building watchtowers and staffing them with guards, how can utility companies ratchet their security up a few notches?

Web-Enabled Surveillance
The answer is that many utilities are turning to proactive systems such as MiniMax’s ScadaCam (see Figure 1), which combines real-time imaging, alarming, and computer network connectivity.

Figure 1. The ScadaCam system is on sentry duty at the Wright-Hennepin Electric Cooperative in Rockford, MN. One of the problems it watches for is overheating, as exhibited by the inset thermal image of a transformer that is far too hot.

Engineered for rugged, unsheltered, industrial use, ScadaCam is a Web-enabled, easily customized, remotely accessible monitoring and control system. The platform provides real-time imaging over a network to any connected PC and archives the video footage as well. ScadaCam is smart enough to notify appropriate personnel when it recognizes a pre-taught type of incident and can even take action autonomously.

Initially equipped with visible light cameras only, ScadaCam has been upgraded by the addition of FLIR’s ThermoVision A20 IR camera. These units allow the monitoring system to detect temperature differentials and thus keep watch in complete darkness as well as monitor the condition of equipment around the clock. The system can be customized to respond in various ways to thermographic changes, motion, and anomalies in the monitored equipment’s behavior. For example, the FLIR A20-equipped ScadaCam can be configured to send an alert when it detects anomalously high or low temperatures or when the average temperature in its field of view suddenly changes, such as when a warm body enters the picture.

Smart IR Cameras
The ThermoVision A20 (see Figure 2) and A40 IR camera families combine microbolometers, optics, and temperature-related electronics in a rugged form factor with flexible, onboard, user-configurable logic; multiple inputs and outputs; standard 60 Hz color video output (RS-170 EIA/ NTSC or CCIR/PAL composite video); and plug-and-play Ethernet or FireWire network connectivity.

Figure 2. FLIR’s ThermoVision A20 and A40 IR cameras detect and measure temperature differentials and so can work through the night. A Web-enabled network allows the ScadaCam to send an alarm to a designated person—or choose another course of action if the situation warrants it—when overheated equipment, the presence of an intruder, or other anomalous condition is discerned.

The A20 can measure temperatures from –20°C to 1200°C with an accuracy of ±2°C or ±2%. The camera includes four internal sensors and a feedback loop to maintain accuracy in varying ambient conditions. It offers four independently configurable target spots/areas, six independent alarming functions, real-time 60 Hz scan speed, and a wide range of output options. Its modular design and small size make it well suited for remote substation or underground vault installation and advanced security applications. A20 camera models have a 160 × 120 pixel focal plane array (FPA), and the larger A40 models have an FPA of 320 × 240.

Designed for network connectivity, the cameras are currently used for remote monitoring, process control, machine vision, design verification, and advanced security applications. Their control capabilities include autonomous reaction to programmable thermal parameters and remote access via Ethernet or FireWire. With FLIR’s LabVIEW Developers SDK and the ThermoVision System SDK based on ActiveX and Visual Basic C++, they can be easily integrated into existing control systems.

Try It Out
You can visit and test-drive a prototype FLIR A20-equipped ScadaCam installed on a test site at a substation of Wright-Hennepin Electric Cooperative in Rockford, MN (see Figure 3).

Figure 3. This graphical user interface lets users control the ScadaCam with a mouse via hub browser connectivity over the Internet. Pull-down menus on the upper left quadrant and the hyperlink-peppered substation map below provide power control options. The image appears in the upper right quadrant window.

Here’s how:
Direct your PC Web browser to www.scadacam.net, and register your name, password, etc. After accessing the graphical user interface (GUI), you will see a series of drop-down menus, including CAMERA SELECTION, LARGER IMAGE (of current image), and so forth. These options let you choose a particular camera, specify the image size and quality, and satisfy other preferences. There will typically be a combination of thermographic and video cameras available.

At the bottom of the GUI is a schematic diagram of the substation, with embedded hyperlinks in various locations in the facility. To point the camera to any preset position, simply place your cursor over a mapped link, e.g., BARN or OIL LEVEL. The cursor will turn into a pointing-finger icon when it’s over a link. Left-click the mouse, and the ScadaCam system will turn the camera to image that area. The image will appear in the window at the upper right of the GUI.

PAN/ZOOM/CAMERA CONTROLS lets you pan around the facility, zoom in and out, and see a wide-angle view of the entire facility by controlling the zoom, with direction image dialogs, or by clicking in the image window. The system is intuitive and easy to learn and use.

Wright-Hennepin and others see ScadaCam’s incorporation of intelligent thermographic capabilities as a valuable innovation that’s helping to replace passive monitoring with a more powerful, capable, and proactive solution. By fully exploiting the onboard intelligence of the IR camera, facilities engineers will be able to empower the system to dispatch digital warning messages or to autonomously control on-site functions via a PLC or relay, completely without human intervention.

Corey Maple is President, MiniMax Corp., St. Paul, MN; 651-251-3005, crmaple@minimax.net.

Leonard Phillips is Senior Writer for Infrared Applications, FLIR Systems Inc., N. Billerica, MA; 978-901-8109, leonard.phillips@flir.com.

For more information, call FLIR Systems at 800-464-6372.

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