All objects emit infrared radiation, and the amount of radiation an object emits increases as its temperature rises. Thermal imaging cameras and other imaging equipment display a color map that identifies temperature differentials of equipment invisible to the naked eye.
For example, since nearly every electrical component heats up before it fails, infrared inspection as a diagnostic method can provide a cost-effective method for identifying potential problems in electrical systems before damage occurs and safety hazards arise. If we find potential problems early enough, remedial measures can be planned and scheduled to our convenience, thus eliminating unplanned production / services downtime.
Infra red imaging thus helps in setting up a condition based maintenance system. Corrective measures could be taken depending on the severity of the identified condition.
Unlike the fragile, bulky, and expensive first and second generation IR imaging equipment, the new-generation equipment is more compact and durable. With the reduction in cost of equipment, it is now possible to get fairly good IR Imaging cameras for about USD 5000.
Of the latest advances in infrared thermal imagery, a few manufacturers have developed technology that integrates infrared and visual — or visible light — images in full screen or picture-in-picture views. The technology helps users recognize image details and better identify problem areas by quickly scrolling through the different viewing modes. They include:
- Full infrared — high-resolution, standard infrared images
- Full visible light — a visible-light image similar to that of a digital camera reference
- Automatic blending — combines infrared and visible-light images blended at user-adjustable levels for maximum image clarity
- Infrared/visible alarm — displays only the portions of the image that fall above, below, or between a user-specified temperature range as infrared, leaving the remainder of the image as full, visible light.
A huge advantage to this application of thermal-imaging technology is that we can perform scanning while the system is live, with no impact on the facility or its operations.
Safe Infrared Scanning of Electrical Panels Starts with Personal Protective Equipment
We can safely scan electrical equipment with a thermal imaging camera in two ways: by leaving the panel closed and scanning through a specialised infrared window or by opening the electrical panel while wearing all of the required personal protective equipment (PPE).
Depending on the arc-flash rating of the equipment, PPE could include but is not limited to protective clothing, gloves, and a face shield. Most arc-flash events happen because of a change in state of the equipment, such as opening a piece of equipment to scan it.
By installing infrared windows, technicians can scan electrical equipment more frequently and safely, as well as without being forced to change the state of the equipment.
Other Thermal Imaging Applications
The thermal imaging applications go beyond electrical systems and cover a few more such as:
- Scan the exteriors of commercial buildings for heat leaks. The thermal imaging equipment allow them to identify places where heat is escaping through the shell or windows or doors.
- Thermal imaging of internal combustion engines help in identifying the health of individual cylinders through comparison of temperatures at the fuel ignition point and the running temperature of each cylinder.
- Many international airports have installed thermal-imaging cameras during the recent H1N1 flu outbreak to help identify travelers with elevated body temperatures as a first-level defense against the virus infected people entering.
- Firefighters use the units to see through smoke and detect trapped people, as well as to locate the base of a fire.
- Law-enforcement officials use them to track down suspects and find missing persons.
- Medical applications are expanding, since inflammation and the resulting increased temperatures accompany many diseases in the human body.
Adapted from a series of articles By Michael Newbury in PE Edition of March 2010