How to buy thermal imagers
Thermal imaging cameras can help give cops superpowers, but only if they are of high-quality – make sure your devices have the features you need and a strong manufacturer behind them
Thermal imagers have multiple uses. They are a great tool in finding suspects on the run and they also can be used to locate heat sources, like a suspected illegal residential marijuana grow or the source of a fire through choking smoke.
Even though prices have fallen dramatically over the past few years, buying an infrared camera is a big commitment. There are dozens of products with thermal imaging technology from a 2x3 inch device that connects to a smart phone, to advanced aircraft-based or permanently-mounted cameras with electronic pan-and-scan, auto-iris zoom lenses and powerful analysis software. Some allow remote access through the internet, letting you share images with first responders and command staff alike.
Here are five important considerations for review before buying a thermal imaging camera:
1. Do you need visible as well as thermal imaging?
If you have a remote camera or it is mounted in a vehicle, you might need a visible as well as a thermal image to fully understand the situation. If the camera is in your hands, you still might not be able to use your own eyes to see what’s going on. Maybe you need to look around or over a wall with a periscope. You can either switch between the camera and your eyes or you can use a dual-spectrum camera.
You might also need to record the image for evidence and it may easier to explain the situation to a jury if they can see both visible and thermal images of a scene. Some cameras support side-by-side or picture-in-picture visible and infrared images.
2. What technical specifications are important for law enforcement?
Thermal cameras have many uses, such as manufacturing, electrical engineering and agriculture, and each application has different needs. Here is what is important to law enforcement:
- Temperature range: Room temperature to a couple of hundred degrees. You don’t need to measure molten metals or cryogenic processes.
- Field of view: How much do you need to see versus how much detail do you need? Some cameras are available with zoom lenses at a higher cost.
- Resolution: Higher resolution cameras can measure smaller targets from farther away and create sharper thermal images, helping you determine exactly what you are seeing if the target is concealed. You need to look at both sensor and display resolution. A high-resolution display with a low-resolution sensor is a waste of money because the quality of the thermal image and its measurement data are always determined by the detector resolution.
- Repeatability: If the imager is aimed at the same type of object in different environments, does it give you the same results?
- Accuracy: Imagers don't just let you see differences in heat, they let you measure those differences.
- Image overlay: Can it overlay the visible and infrared images letting you see visible spectrum details like numbers, labels, signage and texture on top of the thermal image?
If you have a limited budget, you may need to compromise on one or more of these. Which is more important? Many manufacturers say that sensor resolution is the most important spec. See if you can borrow a loaner to try it for a while to see what works for your agency.
3. How does the device store and transmit evidence?
In addition to real-time intelligence, your imager may be used to collect evidence of criminal activity. Look for these features:
- Storage in a standard format such as jpeg and MPEG 4 video with an embedded scale.
- Removable storage using standards like mini- or micro-SD cards.
- Bluetooth and encrypted Wi-Fi access to stream real-time data.
- Can you create instant reports right from the camera, or on your mobile device with a wireless-enabled device?
- Can it perform a wide range of tasks from simple spot measurements to custom calibration?
- Will the software let you take remote control of camera functions like focus, image level and other adjustments? This comes in handy when it’s necessary to deploy the camera on a robot.
5. A strong partner
There are dozens of thermal cameras available on Amazon and eBay at very attractive prices, so why not buy something cheap that you can replace when it breaks? Well your cops literally may be trusting their lives to whatever infrared camera you select and you want one that not only has the functionality you need, but comes from a manufacturer that has your back.
The quality of customer service and the depth of technical support available should be integral to your decision on which infrared camera to purchase.
Find out if your camera manufacturer offers training. I’ll bet your evidence techs got some formal photographic training; your thermographers need training too.
Reputable infrared camera manufacturers want to make sure your thermal imager will serve you well for many years. That’s why some offer extended warranties. Whatever camera you choose to go with, just be sure it comes with a solid warranty that will give you peace of mind.
Thermal imaging cameras can help give cops superpowers, but only if they are of high-quality. Make sure you purchase devices that have the features you need and a strong manufacturer behind them.
Make sure you take your time to determine your requirements and research what is available before you start writing your grant proposal or cut a purchase order.