Smart infrared cameras need skilled operators
Published: 08 April, 2015
Thermal imaging has now become widely adopted for preventative inspection but, although the technology is exceptionally easy to apply, the need for training is more important than ever. It is vital that the camera user understands the science behind thermal imaging. Without it, thermal images are virtually meaningless and findings are at risk of serious misinterpretation. PWE reports.
Thermal imaging is getting smarter as well as much more affordable. What you get for your money, in terms of camera functionality, increases year on year. Even troubleshooting infrared cameras now have standard features that were once only the preserve of top-of-the-range models. Sophisticated user interfaces allow simple point and shoot operation. One click saves the image in a variety of modes, complete with embedded thermal data for subsequent analysis. For those involved in plant maintenance this is essentially good news.
Stuart Holland from the Thermographic Consultancy in Swindon is a Level III thermographer who has worked in electromechanical and building science for thirteen years.
He explained: “When I first started, courses weren’t readily available so I initially learnt through trial and error and believe me, I made mistakes. Certified training has given me a definite advantage and this is the testimony of others too. Even thermographers with more than four years’ experience have been amazed at the knowledge they were missing and how much more they understood following dedicated instruction.”
Training is vital as it not only ensures that the users get the best return on the camera investment but also that application standards are upheld. Indeed best practice guidelines often require those responsible for maintenance to be trained to a specific standard. As a result, courses are now available that range from foundation through to professional level, in three levels.
What do the various qualifications mean?
Any good supplier of thermal imaging cameras will provide a basic level of operational training and they will also recommend the user takes a foundation course. These are aimed at novices in thermal imaging and designed to provide a good basis for further study. They may also be application specific, for example, focusing on HVAC, electrical or building inspection.
The next stage is Level I which instructs the camera user to perform industrial thermographic measurements and fundamental infrared thermography, including basic image post-processing according to established and recognised procedures. This includes the use of measurement tools, emissivity adjustments and span & scale adjustments.
Put simply, a Level I thermographer can use the equipment without knowing too much about its inner workings and perform uncomplicated measurement following existing routines. He or she will be able to detect obvious faults, recognise possible errors in measurement and carry out post processing and data collection.
In the Level I training course, the emphasis is very much on hands-on training. Theory is kept as simple as possible and use of formulas, minimised. Whilst the student leaves the course as a competent user of an infrared camera they would need to defer to a higher-qualified thermographer to define inspection routines and guidelines.
In the Level II course, this knowledge base is expanded. The training course includes more theory and goes deeper into the physical laws that the infrared camera uses to generate an image and measure temperature. It also explores the causes, anomalies and patterns that are commonly encountered in thermal imaging.
The student uses more formulas and is expected to be able to perform simple calculations. Steady state and transient mechanisms are examined in greater detail and the course work involves more laboratory experiments. As a result, the certified Level II thermographer is qualified to perform and direct infrared thermography according to established and recognised procedures.
For any professional thermographer, Level III certification is the gold standard. It signifies wide experience and a standard of knowledge that meets internationally recognised criteria.
The goal of this course is to enable pre-qualified Level II thermographers to set up and run a successful condition monitoring programme. As such, the instruction includes guidance on acquiring and developing the necessary personnel, resources and technologies.
Thermal imaging is a highly valuable technology but only effective at saving maintenance costs and minimising downtime in the hands of properly trained users. It is therefore especially important that training should be planned with the purchase of every camera.
Stuart Holland concludes: “Even though the technology is getting smarter it still requires user knowledge to configure the camera correctly. So, the camera user needs to ask several important questions. Do I understand thermodynamics, conduction, convection and radiation? Can I define emissivity, reflectivity and measure them correctly. Do I know how to thermally tune my camera? If not, get on a training course!”
For further information please visit: www.flir.com