Thermographic analysis — looking at things by the heat they give out, rather than the light they reflect — is becoming an increasingly popular tool in the electronics world, thanks in no small part to the launch of low-cost, smartphone-driven thermal camera hardware.
For professional use, though, it's hard to beat dedicated tools — like the FLIR ETS320, a benchtop entry in the company's dedicated electronic testing range. Boasting a high thermal resolution of 320x240, the microscope-style camera captures 76,800 individual measurements on every push of the button — but it's taken the community, not FLIR itself, to unlock its true potential through the addition of a simple 3D-printed adjustment tool.
The FLIR ETS320 comes pre-calibrated and ready-to-run in a cardboard-and-foam housing with handy carry handle. There's no assembly: The camera module is already attached to the microscope-style stand, and its internal battery holds enough charge to get you up and running — though plugging it in via the micro-USB slot is recommended to get it fully topped up.
The stand includes a textured base, designed to be non-reflective to infrared radiation — meaning it won't show a reflection of the camera sensor — and with a clip for a grounding wire to provide electrostatic discharge (ESD) protection. The camera unit itself slides up and down on the silver mounting pole, and is locked in place with a thumbscrew and an additional fixing ring underneath. Like the microscopes on which it's based, there's also a fine-adjustment knob which moves the camera up and down even when the mount is locked.
The adjustment knob isn't just for show: The sensor in the ETS320 is fixed-focus — in theory, at least — meaning that the position of the camera needs to be adjusted to compensate for the height of the object on test. With a focal distance of around 70mm, that means that the camera module spends most of its time down near the bottom of the mount.
The sensor itself is a 320x240-resolution uncooled microbolometer, common to commercial thermal camera systems. Unlike many of FLIR's handheld thermal cameras, there's no visible-light sensor alongside it — which means there's no opportunity for MSX, the company's "multispectral imaging" feature which blends edge-enhanced visible light imagery with thermal data. It's not much of a drawback: The relatively high resolution of the sensor helps compensate for the loss of MSX.
Finally, there's an internal battery good for several hours of testing per charge, plenty of storage for the small JPEG images the camera captures, and a control panel located next to a bright and clear color LCD panel.
The ETS320 comes bundle with the FLIR Tools+ software package, normally a paid-for upgrade over the company's free FLIR Tools. Compatible with Windows and macOS systems, FLIR Tools allows for the usual generation of reports based on thermal data while adding in the ability to group together thermal and visible light imagery, stitch together multiple thermal images into a larger panorama, and record thermal video files.
The panorama feature is particularly notable thanks to a major drawback of the ETS320's design: The short focal distance of the camera means it can only capture an area of 49x37.5mm (around 1.9x1.4"). By capturing multiple images, moving the board on test between shots, you can compensate for this somewhat — but the requirement for a 30-percent overlap combined with the likelihood temperatures will change between the first short and the last mean it's not a great fix.
For those who don't run Windows or macOS, FLIR Tools+ is a no-go — but that doesn't mean the ETS320 can't still be used. The images it captures can be transferred over USB as a USB Mass Storage device on any system, and contain both a processed JPEG and the raw thermal data itself. As an added bonus, the camera appears as a standard webcam device — though any images or video captured include the full user interface as seen on the LCD panel.
Using the ETS320 itself couldn't be simpler: Hit the power button, with or without anything connected to the micro-USB port, and wait for the device to boot up. After a few seconds of calibration, a thermal image of the stand's base appears; move the board on test underneath the camera and adjust the height until the image appears sharp. When you're happy, press a button to capture an image to the internal memory.
There are a number of settings, accessed using a menu button and directional pad. You can adjust the pre-set thermal emissivity — how easily a surface gives off its infrared radiation, high for something like matte-black plastic and low for polished metal or glass — and choose from a traditional iron, bright rainbow, or black-and-white color palettes. You can also lock the upper and lower temperature scales and have the camera mark where the hottest or coldest part of an object is — a feature limited, sadly, to an even smaller section at the centre of the already-small capture area.
When you're finished capturing the images, the camera connects to a host system via the same micro-USB port used for charging. Images can be automatically imported into FLIR Tools+, if running, or drag-and-dropped from a file browser.
If the object on test has been properly treated — for a populated PCB, this usually means applying a conformal coating of known emissivity, to avoid false readings and reflections — the images captured are sharp and clear, but at 320x240 undeniably small. More eye-catching imagery come from extracting the raw thermographic data, processing it, and applying it to a visible-light image in the manual equivalent of FLIR's MSX — an approach which takes considerable time, but with impressive results.
For technical use, though, this isn't necessary: Even at their native resolutions, the thermal images are clear enough to capture everything from shorted components in the process of overheating to areas which could benefit from a heatsink or other thermal management device. In testing, the ETS320 even showed itself sensitive enough to capture read processes taking place on a microSD card from the heating of the internal components.
The small capture area is a big negative in the ETS320, even with FLIR Tools+'s panorama mode. It's possible to capture a wider area by moving the camera module upwards, but everything quickly blurs into a mush - and the effective resolution of that 320x240 resolution sensor drops accordingly.
Officially, there's no solution to this. Unofficially, there is: A small, 3D-printed tool designed by the thermographic imaging community, and in no way supported or endorsed by FLIR itself, which engages with the lens mechanism and allows it to be screwed closer or unscrewed further away from the sensor.
Using the tool to adjust the lens — there's a handy hole through the middle, so you can monitor the progress of your adjustments in real-time on the LCD - means you can greatly widen the capture area of the sensor. It's a somewhat fiddly process, but the results are impressive — and easily reversed to switch the camera back into microscope-like close-up mode again afterwards.
It's not a destructive modification, but it is a modification nonetheless: It's theoretically possible to accidentally unscrew the lens fully, or damage the threads or sensor — and any such damage won't be covered under FLIR's two-year device or 10-year sensor warranties. For the careful, though, it vastly increases the ETS320's flexibility — to the point where it feels ridiculous that FLIR didn't fit an adjustable lens in the first place, a feature that will hopefully be considered for its successor.
The FLIR ETS320 is a fantastic tool for electronics work, but one that comes at a cost: The device costs $2,499, including the bundled FLIR Tools+ software license. For most hobbyists, it's too much to ask — and you can get similar results, albeit at a lower resolution and without the fantastically adjustable hands-free stand, from a handheld camera like FLIR's own One family or the Seek Thermal range, at a fraction of the cost.
For the professional, or the hobbyist with a bonus check burning a hole in their pocket, it's a tempting proposition — especially if you're working with designs that are likely to need cooling in production. Add in the focus adjustment tool and the ETS320's potential is truly unlocked.
The FLIR ETS320 is now available direct from FLIR.