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 thermalimaging 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. Thermalimaging is used widely in law enforcement, security, the military, air and sea navigation, surveillance, firefighting, private industry, medicine, and science.
The tool used for thermalimaging is the thermographic camera, which is similar in appearance and operation of a portable digital video camera. I 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:
No contact is needed. Keeps the user out of danger.
It is two-dimensional. Thermographic temperatures can be measured at one point or a hundred or more points on a single thermographic image.
It is real time. Allows fast scanning and recording of stationary targets. Objects can not escape their own radiation.
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.
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.
Photo of breaker panel wiring
Same breaker panel as seen with an infrared camera showing an overheating wire and connection leading to the battery charger
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 transmission 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:
Infrared thermal image of an overheating turbocharger on a six cylinder Yanmar diesel engine while running at wide open throttle
A normal infrared thermal image of two Yamaha outboard engines running at high RPM
Infrared thermal image of transom delamination on a center console power boat near the starboard trim tab
Deck core deterioration under the fiberglass on a center console power boat
A "picture in picture" digital / infrared image of fiberglass blistering on a hull bottom with trapped water in the blisters
Infrared themal image of fiberglass blistering near a bow thruster on the port side hull
Infrared thermal image of fiberglass delamination around an underwater light on the transom of a hull
Infrared thermal image of two cracks in the interior of a sailboat's fiberglass hull after being shipped by truck
Infrared thermal image of an overheating 125 volt AC wire connection on the back of the power distribution panel on board a sailboat
Infrared thermal image of the lead ballast inside a fiberglass keel (in the darker purple color)
Infrared thermal image of a Yamaha outboard engine overheating due to a faulty thermostat on the starboard cylinder bank
Infrared thermal image of core replacement in the deck of a sailboat (darker square on the port side of the image)
Infrared thermal image of raised fiberglass tabbing along the stringer and transverse frame on the hull interior of a sailboat
Infrared thermal image of large multiple hull patches from a previous repair in the starboard side of a 65' sportfish yacht that were unseen on the surface of the gel coat
Infrared thermal image of cracks in the hull around the depth transducer from the inside of the hull
Infrared thermal image of significant keel delamination of the fiberglass (in the lighter grey colors) of a sailboat
Infrared thermal image of two overheating branch breakers due to corrosion in the wiring on board a power vessel
Infrared thermal image of the belt on a Perkins diesel engine that was overheating due to corrosion on the groove of the pulleys causing friction and wearing of the belt when running at higher RPMs
Infrared image of core detioration under the fiberglass deck on board a yacht
"Picture in picture" digital / infrared image of cracked gel coat and blistered gel coat resulting from an allision on the fiberglass topside of a large yacht
Infrared image of a in-line six cylinder Yanmar engine running at wide open throttle that was funtioning normally
Infrared image of a Yamaha 115 HP outboard engine running at high throttle that was functioning normally
"Picture in picture" digital / infrared thermal image of the presence of water inside a hull blister during a bottom inspection on a hull
Infrared thermal image of a 24 volt bus bar on board a sailing catamaran with corrosion on the terminals causing overheating due to excess electrical resistance
Multiple areas of trapped water and delamination on the bottom of an older power boat during a bottom inspection
"Picture in picture" digital / infrared thermal image of a hull bottom near the chine with hidden delamination under the fiberglass
Below is a thermal imaging video that was taken of two 2007 Suzuki four cylinder, four stroke, 115 horsepower outboard engines while running during a pre-purchase survey:
Below is a thermal imaging video that was taken of a 2006 5.0 MPI MerCruiser marine engine while the vessel was running at wide open throtte during a sea trial:
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. Thermal imaging is included at no extra charge in all pre-purchase marine surveys. I can incorporate thermal imaging into any kind of other marine survey report and can adjust special pricing for this service based on your needs.
Captain John Banister, AMS® Suenos Azules Marine Surveying and Consulting Palm Beach Gardens, Florida SAMS® Accredited Marine Surveyor ABYC® Standards Accredited Yamaha Certified Outboard Engine Technician Mercury / MerCruiser Certified Technician Honda Certified Outboard Engine Technician USPAP® Training Certificate on Appraisal Standards ITC® Certified Level II Thermographer Member SAMS®, ABYC®, IAMI®, and NFPA®
Note: This page, written content, and all photos were orginally written and published by John Banister in May, 2012. No other person, company or entity has my permission to copy the content of this page (including photos) or any page on this website or other websites owned by me or Suenos Azules LLC. In other words, go to school, get trained on your own equipment before you use it, take your own photos, and publish your own content based on your own work, knowledge, experience, and training. “Infrared Training Center,” “ITC,” and “Flir” logos and designs are registered trademarks of Flir Systems Incorporated and are used on this website and in proprietary reporting with exclusive permission from Flir Systems Incorporated.