Thermal Imaging

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. I prefer using Flir® brand high definition professional grade 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.
Infrared Thermal Cameras Used in My Marine Surveys and Inspections
I only use Flir® brand high definition professional grade infrared thermal cameras in my marine surveys, engine surveys, and inspections. These cameras that I own are calibrated infrared thermal imaging cameras with a minimum of 320 x 240 pixels to a maximum of 464 x 348 pixels with an image frequency of 30 Hz. The cameras I own can detect a minimum of 43,200 - 161,472 individual temperature shots per digital or video image. The minimal thermal range of the cameras I use are between -4 degrees farenheit - 2,732 degrees farenheit (-20 degrees celsius - 1,500 degrees celsius) which means I can see thermal anomalies in cold temperatures (such as freon hoses in marine air conditioning systems and refrigeration systems) and in extremely hot temperatures (such as overheating turbochargers and overheating exhaust manifolds in engines).
Each infrared thermal image I take is properly tuned based on the enviromental conditions at the time of the inspection with special software to reveal thermal anomalies accurately. As an ITC® Level III Certified Master Thermographer, I know how to properly take, tune, and interpret infrared thermal images to determine if there are abnormalities in the thermal images or video taken of hull composites, engines, electrical systems or marine components. I further understand how these systems work and what normal running temperatures are in many different engines and systems on board vessels from years of professional training and experience as a marine mechanic, a marine surveyor, and a thermographer.
My professional thermography certifications and training certificates can be found here.
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.
Thermography and How It Makes Your Vessel More Safe
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
Unseen foam core that can be seen with the infrared thermal imaging camera that is under the gel coat and fiberglass laminates on a hull bottom
Partial resin saturation that did not fully absorb into the fiberglass matting on a new boat
Mercury Verado L6 outboard engine midsections where the internal aluminum exhaust passages can clearly be seen under the saddle panels
A MerCruiser inboard engine with an overheating port side exhaust manifold
Overheating DC cables on a bus bar on board a yacht while powered up
A sportfishing vessel with large unseen patches under the gel coat along the starboard side hull where there was once significant damage
Raised tabbing along the stringer and transverse frame in a sailboat from impact damage
Water collected under a fuel tank in the interior of the boat along the keel of a center console power boat
A Yamaha F300 outboard engine running with a slight raw water restriction in the lower starboard side head
AIr voids seen in the outer skin laminates in the hull bottom of a center console power boat
Debonding of the fiberglass laminates from the balsa core on the hull bottom of a yacht
An overheating head on the port side Mercury outboard engine while both engines were running
Significant delamination on the hull bottom of a sportfishing vessel where seawater has found its way in between some of the FRP laminates
Two overheating branch breakers on a 120 volt power distribution panel on board a yacht
As you can see from the photos above, infrared thermal imaging can reveal many things that may not have otherwise been found using standard marine surveying practices. This is an amazing technology and incorporating infrared thermal imaging into any marine survey or damage inspection gives the boat owner or potential buyer a much better idea of what they are dealing with. As a marine surveyor, I would feel limited in my abilities without having the thermal imaging camera as one of my tools. It only makes for a much better inspection and report. With infrared thermal imaging incorporated into my survey inspections I can submit my findings with a lot more confidence especially when dealing with issues that are beneath fiberglass, rubber, wood, metal heads, or other materials you may find on boats, yachts or in engines. The saying, "a picture is worth a thousand words" goes almost double with infrared thermal images when they are presented to a boat owner or potential buyer. With a good thorough marine survey aided with thermal imaging provides little to no doubt (or argument) of what the true condition (and sometimes value) the vessel is actually in. I believe infrared thermal imaging is the future of marine surveying and engine mechanics and in time will be just as common as the use of the moisture meter among marine surveyors, marine mechanics, and other marine related service professionals. Feel free to contact me about any questions you may have about thermal imaging or to discuss if you think that it may be necessary for your boat, yacht, commercial vessel or marine engine. Pre-purchase marine surveys include infrared thermal imaging on certain components of the vessel as part of the survey inspection. 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.
Capt. John Banister, AMS®Suenos Azules Marine Surveying and ConsultingPalm Beach Gardens, FloridaSAMS® Accredited Marine SurveyorABYC® Standards AccreditedABYC® Gasoline Engines Certified TechnicianYamaha Certified Outboard Engine Technician Mercury / MerCruiser Certified Technician Honda Certified Outboard Engine Technician USPAP® Training Certificate on Appraisal StandardsITC® Certified Level III Master ThermographerMember SAMS®, ABYC®, IAMI®, and NFPA®
Note: This page, written content, and all photos were orginally written, modified, 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 Teledyne Flir Systems Incorporated and are used on this website and in proprietary reporting with exclusive permission from Teledyne Flir Systems Incorporated.
Suenos Azules Marine Surveying and Consulting - Fort Lauderdale, Florida