APPLICATION OF INFRARED THERMOGRAPHY IN NDT

Applications
Electrical
A/C Package Unit Switch		Burned Phase "B" wire
Often Overlooked - Motor Connections		T/F Connection

Mechanical
Motors	Bearings
Energy Loss
Heat Loss	Un-insulated Heating Duct
Building Envelope Roof Moisture
Saturated Roof of Office Building

A Brief Background
Infrared energy is radiated by every physical object in an amount proportional to its temperature. While such energy is invisible to the human eye, it can be measured, recorded and visually presented in a variety of useful formats through the use of today's advanced technology IR cameras and image enhancement computer programs. The resulting information has proven itself invaluable in identifying hidden physical, electrical and mechanical defects, and has been employed within the building management industry for well over a decade. Properly applied, IR technology provides a secondary benefit through its ability to reduce unnecessary maintenance by predicting the occurrence of future operating problems. Typically, an infrared inspection will provide advance warning of an equipment failure or fire threat months to years prior to its normal occurrence. In electrical systems, loose, corroded or poor connections produces heat. Heat, in return, raises electrical resistance - thereby creating additional heat. This runaway cause and effect condition eventually results in an electrical failure and often fire and/or explosion. For mechanical equipment, shaft misalignment, inadequate lubrication, or some other frictional defect is typically the cause of the heat generated. The resulting heat product further deteriorates any lubricants, bearings, seals, or other mechanical components, and again leads to an inevitable failure of the component. Such mechanical failures typically have secondary and costly consequences.
For building management interests, the benefits of IR testing are many. Infrared thermography can quickly expose hidden stresses, damaged components, loose connections, unbalanced loads and other faults in electrical equipment. IR can diagnose problems in rotating machinery by permitting the inspection of the motor shell, motor bearings, load bearings, and other transmission components under physical load. In electrical applications, loose, dirty, corroded or oxidized connections or contacts will produce infrared energy proportional to the amount of heat generated and dissipated due to their increased electrical resistance. In friction generating equipment, heat buildup will show prominently over the ambient surroundings.

For various other applications, the movement of heat energy can be visually traced from one medium to another. It offers additional uses in detecting water leakage in roofs, in finding insulation faults and steam trap malfunctions, in identifying HVAC air distribution patterns and building envelope energy loss, and by detecting underground pipeline leakage.

It should be noted that Infrared Testing is not an absolute science. It cannot provide certainty until further testing, (nondestructive and/or destructive) is completed, or disassembly of the component and/or components is completed to determine if a deficiency or anomaly actually exist. This further testing will also help determine the root cause of an existing deficiency or anomaly.

A final report of all areas found to exhibit elevated or atypical temperatures could then be used by operating personnel to both resolve immediate problems as well as plan or alter future preventive maintenance schedules. Some of the many applications for infrared thermography and the potential financial savings are: