What is Thermal Imaging?
Thermal imaging (also sometimes referred to as thermography, infrared imaging or thermal scanning) is the means by which humans can see the infrared portion of the light spectrum. Every object gives off some amount of thermal radiation so thermal imaging is ideal for observing temperature anomalies that are abnormal in machinery, electrical equipment, and even in solids such as wood, fiberglass, aluminum, and steel. Thermal imaging does not require light to see thermal radiation (like you would see in night vision cameras which require some amount of light) so thermal cameras can see in absolute darkness. Thermal imaging is used widely in law enforcement, security, the military, air and sea navigation, surveillance, firefighting, private industry, medicine, and science.
The tool used for thermal imaging is the thermographic camera, which is similar in appearance and operation of a portable digital video camera. We prefer using the Flir® brand infrared cameras. How an infrared camera works is by sensing electromagnetic waves within the light spectrum wavelength between approximately 0.9 and 14 micrometers (visible light that can be seen by the human eye is between .4 – .75 micrometers).
A special lens on the infrared camera focuses the infrared light emitted by all of the objects in view.
The focused light is scanned by a phased array of infrared-detector elements. The detector elements create a very detailed temperature pattern called a thermogram. It only takes about one-thirtieth of a second for the detector array to obtain the temperature information to make the thermogram.
This information is obtained from several thousand points in the field of view of the detector array. The thermogram created by the detector elements is translated into electric impulses.
The impulses are sent to a signal-processing unit, a circuit board with a dedicated chip that translates the information from the elements into data for the display.
The signal-processing unit sends the information to the color display on the camera, where it appears as various colors depending on the intensity of the infrared emission. The combination of all the impulses from all of the elements creates the infrared image. These impulses will also record surface temperatures of the image taken. Infrared cameras can be adjusted for optimum imaging by manually setting the distance to the object, humidity, and air temperature before the image is taken.
Benefits of Thermal Imaging
There are numerous benefits to thermal imaging in many industires. In the marine industry there are many advantages to thermal imaging. Some of these advantages are:
2. It is two-dimensional. Thermographic temperatures can be measured at one point or a hundred or more points on a single thermographic image.
3. It is real time. Allows fast scanning and recording of stationary targets. Objects can not escape their own radiation.
4. Thermal patterns can be seen. This helps significantly reduce the time and money spent on a technician or mechanic that would have to spend hours to disassemble and troubleshoot a component or go through miles of wiring on a boat or yacht to find the problem. The thermographic image can find the temperature anomaly quickly.
5. Enhances the marine survey report. If desired, thermal imaging can be included in the survey report on components such as engines, transmissions, tanks, electrical equipment, electronic devices, and hulls to look for heat anomalies that can determine if malfunctioning components, leaks, or delamination may exist within the vessel.
Thermography and How It Makes Your Vessel Safer
As you can see in the photos above, thermography can make your vessel (or prospective vessel you are planning to purchase) a safer investment. Thermography can sense heat that may prevent an electrical fire. Thermal imaging can detect leaking fuel or water from tanks that may prevent an explosion or water damage to the interior of the vessel. Thermal imaging can detect temperature anomalies in the engines or transmissions that can prevent much more costly engine or transmissions repairs later on. In the past I have found overheating electric motors stemming from branch breakers that would not stay on and temperature anomalies in several engines that would have lead to much more costly repairs had the thermal camera not been used to find them. Below are some other images I have captured on surveys that show other findings:
Feel free to contact me about any questions you may have about thermal imaging or to discuss if you think it may be necessary for your boat, yacht or commercial vessel. I can incorporate thermal imaging into any kind of marine survey report and can adjust special pricing for this service based on your needs.
Captain John Banister, SA
Suenos Azules Marine Surveying and Consulting
Palm Beach Gardens, Florida
Member SAMS®, ABYC®, IAMI®, and NFPA®
ABYC® Standards Accredited
USPAP® Certified Appraiser
ITC® Certified Level One Thermographer
USCG Licensed Master Captain