What to Look for When Buying an Infrared Camera

Infrared camera photo above by Minea Petratos (Own work) [CC BY-SA 3.0], via Wikimedia Commons

IR cameras, also known as thermal imagers, allow you to get a much different view of the world around you. A regular point and shoot camera only captures light waves from the visible part of the electromagnetic spectrum. However, when it comes to IR cameras, they go beyond the visible spectrum and capture info that is invisible to the naked eye.

By using special infrared sensitive sensors, these cameras can sense black body IR radiation and then offer a visual representation of it. Thanks to this amazing functionality, you can see easily see the thermal characteristics of literally any object.

Why is this such a big deal?

Thermal imagery is very useful, especially for professionals such as electricians and mechanics who need to locate overloaded circuits, detect overheating parts and fix issues before they get worse. Home inspectors also use these types of cameras in order to detect the specific parts of the house that aren’t properly insulated and therefore cause various problems.

What to look for in an IR camera

There are quite a few things you should be looking for when you want to purchase an infrared camera. So if you’re interested in getting one as soon as possible, then the tips below will help you make the right choice.

Image Quality

This is by far the most important trait to look for in an IR camera. Typical cameras have a resolution of 10-12 MP and more, but the truth is that when it comes to IR cameras, the standard resolution is only 120 by 120 pixels. So if you want to go for one such camera, then no one will stop you, but the truth is that low resolutions aren’t going to help you capture enough detail for professional applications.

In order to help you get as much detail as possible, a lot of IR cameras feature a visible light camera which is there for two reasons: one of them is for combining with an infrared image for a more detailed and clearer image and secondly, to capture photographs that can offer some context to the scene.

The quality of the IR images is also influenced by the type of focus the camera features. For instance, if you go for a budget IR camera, then it can be focus free or have a fixed focus. What this means it that its lens was optimized to capture images across a wide distance without having to adjust or fine tune the focus.

Fixed focus does sound and can be convenient in a lot of applications, but a camera with a manual focus can help you focus on things that are generally out of range of fixed focus cameras.

Thermal Precision

Thermal Precision is generally influenced by a camera’s sensitivity, temperature range and accuracy. There are of course many other factors influencing a camera’s precision, but these are the most important factors you should focus on.

Accuracy specs are usually measured as a percentage and they let you know more about the accuracy of the temperature readings your camera is capable of. In general, IR cameras have an accuracy rating of + or + 2%. So when you use them to make measurements, you won’t have to worry about them being off more than 2%.

The temperature range is measured in degrees Celsius and most IR cameras have a range of minus twenty degrees Celsius to two hundred and fifty degrees Celsius. This means that within those readings, the camera is able to obtain an accurate reading.

Lastly, a camera’s sensitivity refers to its ability of distinguishing between various temperatures. So if you want to use an IR camera for work where even the most minutest temperature changes matter, then you should get a camera that can recognize temperature differences of point zero 5 degrees.

Auxiliary Features

Some IR cameras have features such as Wi-Fi connectivity, radiometric video or built-in illuminator lamps which undoubtedly are going to help you take a final decision on which model to get. On top of that, some cameras can also allow you to record or stream video with embedded thermal info. With this kind of functionality, you’ll be able to measure changes in temperature in real time and also record them.

A Wi-Fi capable IR camera allows you to share thermographic info via Wi-Fi easily and fast. Some cameras can also feature embedded laser points or built-in flashlights which help you easily identify the problem areas in your images.


The good news is that most IR cameras feature a very similar design, so you should never select yours based on this trait alone. They also have a rugged outer shell design and an LCD screen that ranges in size from three to three and a half inches. If you go for a high end model, then it’s also going to have a touch sensitive LCD screen for simple use.

In terms of battery, IR cameras feature lithium ion batteries that usually offer about 4h of continuous use. But depending on the model you’re getting, some may also come with extra batteries.

Help and Support

The majority of manufacturers are going to offer you a 2-year warranty when purchasing an IR camera, which means that during this time you’re going to be protected from defects in the detector and in the battery as well. Warranties also cover labor and parts, but there are also manufacturers that split up their warranty to cover only specific components of the camera for different periods of time.

On top of warranty info, you should also look at the calibration options. That’s because in order to remain accurate, IR cameras have to be calibrated periodically. Therefore, before you go ahead and purchase a camera, you should make sure to compare the amount of time it takes to calibrate it and the cost of calibrating it as well.

By helping you to diagnose various problems before they become serious, IR cameras can save you a lot of time, stress and money. Using them, you can easily spot inefficiency in your house, overloaded circuits or overheating machinery. While they may be complex in nature, getting the right one doesn’t have to be a painstakingly difficult process and now that you know what to look for in one, you can definitely make a better decision based on your specific needs.

Ten Infrared Thermal Camera Facts

In the paragraphs below we’re going to discuss some of the more common misconceptions regarding the product quality pricing, mapping performance to apps and capabilities of handheld IR thermal imaging cameras.

  1. A thermal IR camera is able to see below the target’s surface (not true).

The thermal image on the left of someone pouring hot water in a bowl is derived from IR radiation that’s detected only from the surface. As you can easily see in the picture, there is nothing deeper than that that the camera reveals.

  1. Any kind of material can be measured easily with thermal IR cameras (not true).

The information of the temperature is given in the emitted radiation, but the truth is that the imager can also see the transmitted and reflected components. The majority of materials are opaque to infrared, so this means that the energy transmitted can be ignored. On the other hand, it’s good to note that a lot of materials with a lot emission level do reflect IR radiation.

  1. Thermal measurements can be influenced by the target’s color (not true).

One thing you should know about emissivity is that it is not related to color. This means that the colored labels you can see below all have the same temperature.

  1. Never use thermal imaging cameras in daylight (not true).You should know that when it comes to IR imaging cameras, they aren’t able to detect visible light. Two thermal images of an object which are taken under both day and night illumination levels will be basically identical and the camera only responds to the object’s long wave IR signature.
  2.  An increased sensitivity of the thermal IR camera improves its overall function (not true).

One thing you need to know about thermal cameras that have a high thermal sensitivity is that they’re quite expensive, so that is why before you get one, you should determine your application’s requirements. For the majority of engineering and inspection applications, a thermal sensitivity of one degree Celsius is more than enough.

  1. Visible image capture or image fusion are must have features for a thermal IR camera (not true).

When it comes to image fusion, it’s usually required by the military for target identification. In certain low light conditions, the image displayed by digital or analog fusion of IR or visible images has better clarity compared to either the visible or IR images. The thing is that in this case, there’s no quantified thermal data in the images. Sure, no one says that this is not useful for the military, but thermal visible image fusion isn’t necessary for thermal analysis.

  1. If the camera is more expensive, it’s going to perform better in terms of sensitivity and temperature range (not true).

You’ll be surprised to find out that there are a lot of great fixed position and handheld thermal cameras that start below two thousand dollars.

  1. Thermal imaging cameras can only be used properly by scientists and engineers (not true).

It’s already very well known that non technical personnel can easily set up and use these types of cameras by taking 4 day classes. In fact, you should know that there are many beginner courses available worldwide and they’re also free of charge or very affordable to consider.

  1. Affordable thermal cameras can only be purchased from outside the United States (not true).

One thing you should know about this is that in the United States there are many thermal imaging cameras manufactured and that is because the costs are pretty low. There are also many inexpensive thermal sensors manufactured here, so you can expect that getting a thermal camera here will run you pretty cheap.

  1. The price for thermal imaging cameras will drop under 1000 dollars soon (not true).

No one denies that there have been many advances in the field of thermal imaging camera manufacturing, but there is still a long time to go until they can become very affordable. Therefore, if you plan on getting one now, then get it, since the prices won’t drop anytime soon for obvious reasons.

Using Infrared Thermal Imaging for Home Inspections

IR is a non-invasive and very advanced technology that is greatly used by home inspectors in order to show their customers the various parts of their homes that have various problems which cannot be detected during a regular home inspection. Although benefits of thermal imaging inspection can be recognized in all parts of the US, the most rewarding would be most likely for the homeowners / buyers in climates characterized with significant temperature variations: cold winters and hot summers.

This article was inspired by a story I heard from my folks from Norther Illinois. Despite my suggestions they postponed performing a home inspection until finalizing their real estate purchase and moving into the house. That unfortunate decision resulted in rather costly home improvement job or should I say a few projects, the house was cheap but still….

They had to perform new window installation in Chicago home, replacement of their old siding, and install a new roof / gutters. Having a home inspection done before the purchase or at least an infrared camera scan could have save them a lot of money.

Let’s go back to our main subject, since thermal imaging inspection is highly specialized, it’s vital that the info the customers are presented with meets their needs and they can use it in order to take action and fix the issues their home is dealing with.

One of the main things you should know about infrared imaging inspection is that the results interpreted by the inspector need to be very accurate. If they’re not, then the customer won’t know what kind of action he should take in order to deal with the various issues affecting his property.

I encourage you to watch this video from FLIR, the leaders in IR cameras.

Inspectors should generally:

a) Explain the pros of thermal imaging and the benefits customers can get when considering such services. As an inspector, it’s very important that you have marketing materials that you can give to your clients which outline the various issues that can be detected through IR.

b) Explain the limitations of IR imaging, including the fact that it can also be used in order to predict future problems. Keep in mind that if your roof for instance, has been detected to experience moisture intrusion, then it’s certainly going to cause you a lot of trouble in the future if you don’t repair it as soon as possible.

IR inspections can easily document and identify the energy loss, moisture intrusion and also hot spots. When it comes to energy loss, infrared cameras can detect:

  1. Broken seals in double pane windows.
  2. Missing insulation around window frames
  3. Structural defects such as missing framing members or under-fastening.
  4. AC compressor leaks.
  5. Malfunctioning or damaged radiant heating systems.
  6. Air infiltration or heat loss in doors, windows, floors, ceilings and also walls.
When it comes to moisture intrusion, an infrared imaging camera is able to detect:

a) Moisture and water intrusion at the building envelope, foundation and around penetrations which could cause mold and structural damage.

b) An infrared imaging camera can be used to detect hot spots in the house, including:

  1. Electrical faults prior to them causing a fire.
  2. Overheated electrical equipment.
  3. Undersized and overloaded circuits.
  4. Circuit breakers that require immediate replacement.
Depending on the color gradients the IR imaging provides, home inspectors are able to detect:
  1. Hazardous flue leaks which can cause CO poisoning of the house’s occupants.
  2. The presence of intruders, including large pests, mice and rats hiding in the home’s structure. The IR camera can detect them because of their heat signature.
  3. Potential pest infestation as it’s revealed by energy loss through shelter tubes.
Standard Images with IR Images

One of the best things about the IR report is that it’s user friendly. So the way it goes is that after it’s done, the home inspector is going to show the customer the standard images side by side with the infrared images. As a result, the client will be easily able to locate the problem points in his house and then address the issues.

Interpreting the Data

In order to ensure the home inspector provides a solid infrared imaging report, he needs to make sure that he knows exactly how to interpret the data. It’s a process that greatly depends not only on his experience, but also on his level of training as well.

Based on the locations of the images and the established baseline infrared readings, the results can show customers the critical repairs that need to be made (for instance electrical hot spots) or maybe show them one or more items that need to be kept in check (such as insulating an interior or maybe an exterior wall).

Since overall, thermal imaging equipment is very expensive, not every home inspector can offer such services. However, if you’re someone who wants to see exactly what’s wrong with your house and make the required repairs or improvements to enhance its energy efficiency, then you certainly need to take some time to research a great home inspector that offers thermal imaging inspections.

Just remember that before hiring one, to ask him several questions regarding his experience, the equipment he’s using and the types of problems that can be detected throughout this process.

Home Energy Auditing with Thermographic Camera

When it comes to energy auditors, they will generally use thermography or IR scanning in order to detect air leakage and also air defects in building envelopes.

The way a thermographic inspection works

One thing you should know about thermography measures is that they use still cameras and IR video in order to measure surface temperatures. The tools are basically going to detect light from the heat spectrum and the images on the film or video will record that variations in temperature that exist throughout the house.

The colors in which these temperatures are going to be displayed in range from black for cooler areas and white for warmer areas. Based on the images he gets, the auditor will determine whether the homeowner needs to consider insulating his house or not. The images also act as a QC tool which tells the homeowner whether his insulation was properly installed or not.

One thing you should know about thermographic inspection is that they are either an exterior or an interior survey. Depending on the weather condition, the home inspector will take a decision on the best method he can use in order to inspect the house. Most of the times though home inspectors will do an interior scan and that is due to the fact that warm air that escapes from a building won’t always move in a straight line through the walls.

If there is any heat loss detected in one area of the exterior wall, then it may be caused by a flaw inside the wall. On top of that, detecting temperature differences on the property’s outside surface is a bit harder during windy weather. Because of that, in such cases, an interior survey is a lot more accurate since it benefits from a minimized air movement.

Concerning thermographic scans, they’re generally used while a blower door test runs. What the blower door does is that it increases the air leaking issue through the various defects in the building’s shell. As a result, the air leaks are going to appear as black streaks in the IR camera’s viewfinder.

Not only is it necessary to have your home scanned in order to assess its energy efficiency, but you should also consider it before you buy a new house. You may think that new houses are exempted from such problems, but the truth is that there are many of them which aren’t built properly and have severe air leakages.

Watch this very short video for an infrared camera in action and continue reading below the video clip.

Devices used for thermographic inspections

There are many kinds of devices that energy auditors will use in order to detect the energy efficiency of a property as following:

  1. Point radiometers are one of the simplest tools used during one such inspection. What this does is that it measures the radiation in one spot at a time and then shows the meter reading of a certain spot. In this case, the auditor is going to carefully pan the area with the device and then write down the various differences in temperature he finds.
  2. Thermal line scanners are also used for showing radiant temperatures that’s viewed along a line. This is a process which is going to show the various temperature changes along the line.

The IR imaging camera is currently one of the most effective devices for detecting a property’s energy efficiency and that’s because it produces a 2D thermal picture of the area and lets you see exactly where heat escapes from your house.

How to prepare for a thermographic inspection If you want to use such services, then you should first of all take the required steps that would allow the inspector to provide you with an accurate result. This includes removing drapes and also moving furniture away from the walls.

The most accurate thermographic images are going to be produced when there’s a great temperature difference between the exterior and interior air readings. In northern states for instance, thermographic scans are usually done in the winter. If you live in a southern state though, the scans will generally take place during good weather when the AC is on.

Keep in mind that in certain period of time year, you may be required to maintain a certain exterior/interior temperature difference for up to 4h before the inspector can perform the test.

Infrared Imaging Explained

If you’ve wondered what infrared imaging is all about, then you’re probably someone who loves physics a lot. Nevertheless, this is a method of capturing IR images not visible to the eye which are then going to be converted into images visible to the human eye. As humans, we can only see the visible light, but this is only a very small part of the electromagnetic spectrum. But what is this spectrum, you ask?

Well, it’s a special scale that classifies the various forms of electromagnetic radiation, such as radio waves, microwaves, infrared rays and so forth. So if you’d like to see in infrared light, then you’ll need to use infrared cameras and imagers since they feature special sensors which don’t operate by using visible light.

Any object or organism that has a temperature above absolute zero will be able to produce infrared radiation. However, when temperature increases, this also causes the molecular and atomic activity to increase which means that more thermal radiation or heat will be produced. This in turn is going to emit more infrared radiation.

Infrared radiation that is reflected from or emitted by warm objects can be easily picked up by long-wave thermal infrared imagers. This is because the imagers feature lenses that can have as much as 7000 sensors which can easily convert IR energy into electrical signals which are then going to finally be converted into a visible image.

What’s special about infrared light is its ability of penetrating areas which visible light could never be able to, allowing it to reveal obscure objects. As one can imagine, this makes it very useful in a lot of applications and it’s generally used by the military in order to produce gun sights, binoculars and other infrared imaging devices.

Firefighters, police and many other agencies can use these imagers to rescue individuals who are lost at sea, lost in the woods, to catch criminals and so forth. As a technician using infrared imagers, you can easily located under-heated or overheated parts in order to eliminate leaking chemicals that can lead to potential hazards.

Lastly, if you’re an archaeologist, you can use these imagers in order to monitor archaeological sites and examine artifacts, while if you’re a wildlife researcher, you can use them for studying warm-blooded animals in their natural habitats. There are currently many luxury cars, planes and ships that use infrared images, but they’re also used in astronomy telescopes and space satellites for research.

Infrared Imaging Bascis

Infrared Imaging, Infrared Thermography, and Thermal Imaging refer to a process of using thermographic cameras to produce images by detecting radiation in the infrared range of the electromagnetic spectrum. That range is roughly between 900-14000 nanometers.

And here is another way to put this: all types of objects emit infrared light / energy in a form of heat. Because each of the objects / its components as well as parts of our body have slightly different temperature an infrared camera sensor detects those temperature variations and “paints” an image based on those readings. Because the output image is based on radiation, dark or bright environment does not affect the image.