Frequently Asked Questions

What is infrared radiation and how does it relate to problem detection?

Everything that has a temperature emits infrared (IR) radiation . The amount of IR radiation emitted at a certain wavelength, from the surface of an object, is a function of the object's temperature. This is a very important concept, since it implies that one can calculate the temperature of an object by measuring the infrared radiation emitted from it. Detectors in todays infrared imagers translate incoming IR radiation patterns from an object into visual maps that co-relate image intensity or colour to the amount of IR radiation recieved from that object. The amount of radiation receieved, along with other parameters, is used to calculate the actual surface temperature of the target object. The detectors are extremely sensitive to minute temperature differences and, under the control of a trained thermographer, temperature calculations are accurate and reliable.

What is a thermal anomaly?

Any disequilibrium or gradient in real or apparent surface heat distribution and/or magnitude, with respect to a uniform reference temperature, which should not exist under normal or ideal conditions.

What is emissivity?

Emissivity is a term used to describe how effective a substance is at emitting electromagnetic
radiation at a particular wavelength. It not only depends on intrinsic thermophysical properties of a particular substance, but also on an objects surface characteristics, and the direction the radiation leaves this surface. Determining material emissivities is important when deducing its temperature from the amount of infrared radiation it emits.

What are the advantages of using infrared imaging for temperature
measurement?

1. Measures temperature without contacting object.

2. Minimises maintenance downtime because equipment does not have to be taken offline for
inspection.

3. Detects fault conditions before they lead to outright failure.

4. Will not deface or destroy the product being inspected.

5. Takes temperature measurements within milliseconds rather than seconds as with contact methods.

6. Can be used to study and analyse transient phenomenon or moving objects.

7. Can measure the temperature of irregularly shaped objects.

8. Measures through hazardous atmosphere.

9. Does not act as a heat sink as do contact methods.

10. Collects large amounts of data in a short period of time and can store this data for future reference and trending.

What is Infrared Radiometry?

Radiometry is the study of the physical principles behind how electromagnetic radiation is detected and measured. It also includes information on the design of different radiation detectors and the associated science of optics. The sub-field of radiometry that involves calculating temperature using the infrared part of the electromagnetic spectrum is termed Infrared Radiometry.

What is Infrared Thermography?

Infrared Thermography (IRT) is the applied discipline of combining infrared radiometry, heat and mass transfer theory, and thermodynamics for the purpose of qualitative and quantatative non-destructive testing.

Who is interested in using Infrared Thermography?

Property managers, engineers and facility managers of all types are always concerned with the condition of buildings and equipment under their care. All would agree that proper maintenance, management of energy resources and quality of construction are necessary for optimising safety, performance and cost savings.

Veteranarians and doctors are using infrared imaging to analyse surface thermal patterns that are symptomatic of an underlying ailment or condition. Nowhere is the value of clinical IRT for animals more evident than when its applied to the care of horses. Many minor injuries to muscle tissue may go unnoticed until the problem is more severe. However, infrared imagers used today can pick up the smallest change in temperature as a result of increased blood flow to damaged tissues. In this way IR imaging aids the expert trainer in caring for the horse.

Manufacturers concerned with non-destructively testing product quality and performance, are also among those employing, infrared radiometric technologies. An automobile manufacturer might use IRT to measure the real-time thermal dynamics of a prototype engine block or a plastics manufacturer might be interested in monitoring its extrusion process. Many industrial processes implicate the use of IRT where temperature and heat flow are a useful indicators of how a process is operating.