An infrared (IR) camera can help increase your productivity on the job, whether you’re tasked with inspecting electrical power lines, searching for faults in wiring or trying to find the source of energy loss in a home or commercial building. It’s therefore very important to choose an IR camera—or thermal imaging camera—that will offer not only the features you need to work efficiently, but also the quality, technical support and service that add value to your investment.

There are lots of thermal imaging cameras to choose from, ranging from extremely affordable point-and-shoot models to highly specialized HD-level science and research cameras. Here are eight key aspects to consider when choosing a thermal imager.

1. How to you plan to use it?

If your specialty is weatherization, you may only require a lower-cost point-and-shoot model to spot missing insulation, poor weather stripping and leaking windows. On the other hand, an energy auditor may want a more advanced model that can generate professional, customized reports and automatically upload images to secure cloud storage. And predictive maintenance professionals may need a high-resolution thermal imager with a removable telephoto lens to scan electrical power substations or power lines from a safe distance.

While your application can dictate the type of thermal imaging camera you need, you should look for the model within that category with the highest detector resolution (and therefore, image quality) that your budget allows. Higher resolution means that each image contains more information: more pixels, more detail and a greater likelihood of getting an accurate measurement. With more pixels you can measure smaller targets from farther away and create sharper thermal images, both of which add up to more precise and reliable measurements.

2. How long will you use your camera each day?

The camera’s weight can be a significant concern if you’ll be using it frequently or for extended periods of time. A lighter thermal camera will decrease strain on your shoulder and back during long inspections. A wide selection of compact, light point-and-shoot thermal cameras fit nicely into toolboxes and utility belts and pouches. Some models have lens systems that tilt along a 180-degree axis allowing users to keep the viewing screen comfortably in front of them while rotating the optical block straight up or down to scan hard-to-reach targets – perfect for a day full of overhead duct inspections, looking behind motors, under workstations and aiming from other challenging angles.

Another important consideration is the thermal camera’s interactive controls. Does it have dedicated buttons, a touchscreen or both? A few extra simple buttons that are intuitively positioned can make the camera easier to use as opposed to relying on one button to step through menu options.

Finally, make sure your camera is outfitted with at least two batteries (Lithium ion or better) that can be quickly and easily switched out in the field so you can keep working efficiently.

3. How high do you need to measure?

Check the thermal imaging camera’s specifications to see the full range of temperatures for which it is calibrated and capable of measuring. Think about the temperatures you’re likely to encounter in your application and select a camera with a range that meets or exceeds the highest temperature you’ll see. This is especially important for industrial applications such as measuring high-temperature equipment like boilers, kilns or furnaces. Some cameras have multiple ranges to measure a wider span of temperatures more accurately.

4. Will your target subjects be close, far away, or both?

Trying to measure a hot spot along overhead power lines using a thermal imager with a wide field of view (e.g., 54 degrees × 42 degrees) is just an exercise in frustration. For inspections on subjects overhead or at a distance, you need a thermal imaging camera that offers a telephoto lens with a narrow field of view (FOV) like 14 degrees × 10 degrees or 6 degrees × 4.5 degrees. For up-close work, a wide-angle FOV of 45 degrees or higher will allow you to capture more of the scene. Most camera specifications will list the camera FOV, but it’s important to understand that FOV is determined by the lens, not the camera itself. Choosing a thermal imager with removable lenses and a good selection of lens FOVs will give you the most options during thermal inspections.

Choosing a fixed lens thermal camera can be less expensive but note that many are considered “focus-free” or “fixed-focus,” meaning you can’t adjust the focus yourself. If precise temperature measurement is vital to your work, choose a camera that allows you to control the focus through manual focus, autofocus or both.

5. How consistent and accurate are the measurements?

Infrared cameras don’t just let you see differences in heat; they let you measure those differences, which means the accuracy and consistency of the measurements is a very important factor when determining the value of a camera. For best results, look for a thermal imager that meets or exceeds ±2% (or 3.6 degrees F) accuracy.

Producing correct and repeatable results also requires in-camera tools for entering “emissivity” and “reflected temperature” values. These settings should be easy to find and adjust while in the field, so you can record the most accurate temperature measurements.

Other helpful diagnostics to consider are multiple moveable spots and area boxes for isolating and annotating temperature measurements you can save as radiometric data and incorporate into findings for reports.

6. Do you need to present your findings to others?

Digital photos that correspond to your thermal images will help you further document a problem and communicate its precise location to decision makers. Therefore, consider buying a model that’s outfitted with a visible-light camera, illuminator lamp and a laser pointer as well as the thermal camera. There’s no need to carry a separate piece of equipment to document the location or the asset you’re inspecting. A built-in visible light camera also supports images that combine the visible and thermal into one picture such as the images below. Key elements from the visual image are in use, allowing you to see writing and other features that help identify the scene.