What is Thermographic Testing?
Thermography is a method of inspecting mechanical and electrical equipment by means of non-contact imaging and analysis of thermal energy from the surface of the object. This inspection method is based on the fact that most components in a system show an increase in temperature when malfunctioning. The increase in temperature could be due to a worn bearing for a mechanical equipment and loose connections in an electrical circuit. By observing the heat patterns in a system components, anomalies can be located and their rating can be evaluated.
Thermographic Testing is used as a predictive maintenance tool for plant and machinery. This technology has particular application for electrical systems and has the ability to identify electrical connections that could possibility fail in the future.
What equipment is used in Thermographic Testing?
The equipment used by Thermographers is the Thermal Imager. These are specialized devices which measure the natural emissions of infrared radiation from a heated object and produce a thermal picture. The resulting image is directly related properties and composition of the object, and the operating condition during the inspection.
What are the benefits of Thermographic Testing?
The benefits of Thermographic Testing are,
- Reduced electrical fire potential by identifying faulty connections
- Minimizing breakdown potential in production processes
- Able to identify preventative maintenance needs which can then be planned
- Reduced risk of fire, equipment downtime and business interruption
- Lower maintenance costs and extend equipment life
What is the Scanning Process?
The Thermographic scanning process is carried out with machine and equipment operating under normal load conditions. It is preferable to be able to scan equipment when operating at its maximum operating capacity if possible.
Thermographic scanning relies on a direct line of sight to the equipment or surfaces being scanned for temperature variations. For this reason the main task with carrying out Thermographic scanning is the opening or removing of covers over switchboards or connections. The technician is required to remove covers and open switchboards and this should be arranged prior to the commencement of the survey.
How is the report prepared?
After the scanning is completed and anomalies have been identified a report is produced. This uses images saved electronically to the camera. A digital photo is used as a reference to identify the location of the connection and equipment. The report will show a color image of the anomalies which are analyzed and then recommendations or rectification are provided. The problem is also prioritized as to the seriousness of the anomalies.
Sources:
Infrared Thermographic Testing Modules - PNRI
