Quality Assurance Through Infrared Imaging

Fig. 1   The dark loops revealed in this grey-scale infrared image (Fig. 1) are electric heating circuits embedded beneath ceramic tiling. The imaging camera does not "see" through the tile. Instead, it pictures the transfer of heat from the wire loops through to the tile surface. Both, the quality of workmanship and operation of circuits can be quickly visualised and quantified.

Knowing and controlling the temperature of welds is important to maintaining a quality product. In this case (Fig. 2) a manager at a flywheel production plant wanted a quick, non-contact method of determining the temperature and uniformity of the welds after the flywheels had exited the arc-welder and were moving on the conveyor. IR imaging was suggested and to the manager's surprise the temperature was degrees below what he had expected.   Fig. 2

Fig. 3 Paved surfaces can be inspected for sub-surface voids and delaminations. After a severe leak from a water main, the extent of damage to the gravel base of this paved surface (Fig. 3) was determined using infrared imaging. Some of the voiding has already been repaired (the warmer red area at the top of the image) by back filling with a gravel mixture. The infrared image shows that the extent of damage is greater than originally assumed (blue areas).

The thermogram (interior view of ceiling section) to the right (Fig. 4) reveals deficient insulation. Improper installation practices are a major cause of poor energy management and can be avoided. Quality control at the construction phase is essential to maintaining efficient use of energy resources and money. Using infrared thermography, large facilities can be inspected quickly. Qualitative and quantitative analysis can be performed to assess the integrity of the building envelope. Homeowners or those considering the purchase of a new or used home can quickly and cost-effectively inspect the building envelope and window seals for efficiency and quality of construction. Fig.4