Infrared Thermography Study

What is Thermography?

It is a thermal analysis tool that has become widely used for preventative maintenance on mechanical and electrical systems. Infrared Thermography is the technique that uses an infrared imaging and measurement camera to “see” and “measure” invisible infrared energy being emitted from an object.

Principle of Thermography

Thermal, or infrared energy, is energy is not visible because its wavelength is too long for the sensors in our eyes to detect. It is the part of the electromagnetic spectrum that we perceive as heat. Everything with a temperature above absolute zero emits infrared electromagnetic energy. Even cold objects such as ice cubes, emit infrared radiation. The amount of radiation emitted by an object increases with temperature. The higher the temperature of the object, the greater the infrared radiation emitted. The Infrared camera allows us to see what our eyes cannot. Therefore, Thermography allows one to see variations in temperature. When viewed through a thermal imaging camera, warm objects stand out well against cooler backgrounds; Thermal imaging cameras detect radiation in the infrared range of the electromagnetic spectrum (roughly 9–14 µm) and produce images of that radiation, called thermograms.

Why Thermography is required?

Thermography is one of the preventive maintenance tools. Thermography can be useful in identifying potential issues. In the industrial/commercial environment, almost everything gets hotter or cooler before it fails. The primary benefit of including a thermographic survey in a preventative maintenance program is the ability to monitor thermal trends over time. However, infrared reports often fall short, by not including necessary information required to understand historical trends. This information is necessary for the electrical equipment manufacturer to assist the customer with evaluating equipment operational concerns.

Failure of equipment, machine in electrical or any system may result in loss of production, injury, fire or other damages to property etc., all resulting financial loss. IR Inspection identifies fault sites in advance and suggests for corrective actions based on fault severity. IR Thermography removes unnecessary preventive maintenance and typically in ordinary circumstances 30 to 40 % of the maintenance costs can be saved.

Thermography advantages

  • It Finds problem before it finds you

  • Less expensive

  • Reduce maintenance cost

  • Extend asset life

  • Reduce inventory base

  • Increase product quality & consistency

IR Inspection methodology

  • It involves scanning

  • Image taking and image analysis of thermograms

  • Report Preparation (Report contains methodology adopted for the study, Executive summary, analysis of the data obtained through field study, measurements, possible recommendations of the study etc.)

  • All above activity would be carried out by certified Level-II Thermographer

Guidelines for IR Inspection

American Society for Non Destructive Testing (ASNI) is an apex organization; it gives guidelines for performing effective IR Thermograph inspections in both qualitative and quantitative.

  • Qualitative: gives only images not the temperature data

  • Quantitative: gives images, temperature data

Caution:

Infrared thermography is currently being used in two distinct ways for preventative maintenance. It is important to remember that infrared scans are only one of many activities necessary in a preventative maintenance program. They should not replace the standard maintenance procedures found in the instruction and maintenance manuals for the electrical equipment.

Few thermal images