Flir TG165 Thermal Imaging Thermometer Review

Flir has come out with the TG165, their first-ever imaging IR thermometer. Flir offers a wide range of thermal imaging cameras, and is perhaps the biggest name in the thermal imaging business. The TG165 imaging IR thermometer is built with Flir’s new Lepton micro thermal camera and features thermal image resolution of 80 x 60 pixels.

The TG165 will be priced at $499.

As with other IR thermal imaging and temperature measurement tools, the TG165 works by capturing the infrared light that all objects and materials emit. The amount of infrared energy emitted by a subject depends on how hot it is. Thus, the intensity of infrared energy can tell you how hot or cold an object is. An IR thermometer will give you a non-contact temperature reading, while a thermal imaging device will show you the relative thermal properties of a subject or targeted area in the context of its surroundings.

For instance, an IR thermometer might tell you that the temperature of a circuit breaker in a panel is at 120°F, while a thermal imaging tool might show you that one circuit breaker is at an elevated temperature while surrounding breakers are cooler, indicating an imbalanced load.

The TG165 does both of these things.

Instead of hunting around for hot or cold spots as with a regular IR thermometer, the Flir TG165 imaging IR thermometer uses thermal imaging to show you the subject of interest. Then, the IR thermometer gives you a temperature reading for that spot.

Introduction and Features

Flir sent over a TG165 test unit a couple of days ago, and I have been putting it through it paces. Overall, I am impressed with the tidiness of the whole package, and how truly point and shoot of a device this is.

Flir also recently released the Flir One, a $350 iPhone thermal imaging module that is also built with the Lepton core. The next least expensive Flir thermal imaging product is the Flir E4, an entry-level thermal imaging camera that provides spectacular results, partially thanks to the built-in MSX contrast enhancement feature.

I walked into the review thinking that the TG165 would be a sort of slimmed-down version of the E4, but that’s not really a good way of putting it.

Flir purposefully describes the TG165 as an imaging IR thermometer, and not a thermal imaging camera, and after using it for a bit, I think that they were spot-on with the description. They also steered away from the visual IR thermometer language other brands use, for reasons I will discuss in a little bit.

Instead of the Flir TG165 being designed as a poorly featured thermal imaging camera, it seems to be designed as an advanced IR thermometer that is a big step up from basic IR thermometers. It’s a sort of go-between that bridges IR thermometers and thermal imaging cameras. The TG165 offers better measurement insight compared to IR thermometers, and is simpler to operate than thermal imaging cameras.

Compared to visual IR thermometers currently on the market, such as the Dewalt 12V model, Fluke VT02, and Fluke VT04, the TG165 offers far greater imaging resolution.

Compared specifically to the Fluke VT04, the Flir TG165 offers a wider field of view, slightly better accuracy, and a wider temperature measurement range, just to name a few advantages.

But to be fair, the Fluke VT04 and Flir TG165 work very differently. The Fluke overlays a thermal image on top of a visual image, making it more a visual IR thermometer, as it’s called. The Flir only provides a thermal image, making it truer to its description as an imaging IR thermometer.

The two approaches result in two very different types of images.

Flir provided some product imagery that, in my opinion, don’t do justice to the TG165’s small size. It’s not miniscule, but it’s barely larger than some of the premium IR thermometers I have used or tested. It has a nice build quality, and feels more solid than some of the other thermal imaging products I have handled before.

The TG165 is actually water resistant to IP54 standards, and is rugged with a 6.5 foot drop rating.

It features a dual laser targeting system, which can be turned off, that can be used to assist with aiming. This is helpful since there is no visual camera module to provide non-thermal contrast or clues as to what is actively being measured.

The TG165 has a spot ratio of 24:1, meaning at a distance of 24″ it measures the temperature of a spot 1″ in diameter. The dual lasers are most effective at distances beyond 36″ to indicate the area being measured.

Here are sample images, provided by Flir, of:

an active circuit,

refrigeration coils,

an overheating motor,

an overheated electric power component,

and anomalous heater or cooler performance.

What I like most about the TG165 is its a near-instant-on tool. Most other thermal imaging products are slower to turn on.

How it Works, Compared to Other Thermal Imaging Products

Even though the TG165 is built with a thermal imaging sensor with 80 x 60 pixel resolution, you do not get 4,800 temperature measurement data points. With a truth thermal imaging camera, such as the Flir E4 or another E-series camera, you get as many data points as there are sensor pixels.

With the Flir TG165, there is one single spot IR thermometer that provides temperature measurements. This is where the 24:1 spot ratio comes into play.

The Flir E4, a true out-of-the-box thermal imaging camera with a 80 x 60 pixel thermal resolution, you get 4,800 individual temperature measurements.

With the TG165, the thermal imaging sensor is only used for imaging purposes. A separate IR thermometer perfectly aligned with the imaging sensor is used for temperature measurement purposes. You can see this in the first image of the post, which shows the front of the device.

Specifications

• 80 x 60 pixel thermal imaging sensor (4,800 pixels total)
• 2.0″ LCD display
• 150 K thermal imaging sensitivity
• 150 ms response time
• -25° to 380°C (-13° to 76°F) temperature measurement range
• 24:1 IR temperature sensor spot size
• Adjustable emissivity
• 9 Hz frame rate
• 2 color palettes – grey scale and “hot iron”
• BMP saved image format
• Accepts micro SD cards
• 1/4″-20 tripod thread
• Built-in rechargeable battery (via microUSB)
• 8-hours continuous battery life ensures the battery will last through a typical workweek of 8 hour days

The Flir TG165 has its benefits, and its tradeoffs.

Pros

• Thermal imaging provides more insightful temperature measurements than simple IR thermometers
• Simple enough for effective use without the need for thermography training
• Turns on nearly instantaneously
• Narrow 24:1 temperature measurement spot size
• comfortable grip
• No calibration delays
• No need for manual lens focusing
• Water-resistant design
• Smaller and lighter than thermal imaging cameras
• Can easily fit inside a tool bag or pouch

Cons

• No built-in visual camera
• No MSX visual contrast enhancement feature
• Only 2 color palettes

Price: $499

Buy Now(via Amazon)
Compare(E4 via Amazon)
Compare(Fluke VT04 via Amazon)
More Info(via Flir)

First Impressions

Flir says that the TG165 will be a must-have tool for electricians, HVAC techs, building contractors, maintenance techs, mechanics, and hobbyists.

Compared to simpler IR thermometers, the TG165 is a more capable test and measurement tool. It doesn’t tell you the temperature – it shows it to you. Well, it actually does tell you the temperature of whatever it is that you’re measuring, but in the context of what’s around it.

I have started testing the TG165, and thus far I’m really liking it.

Admittedly, it took me a couple of minutes until I understood how the imaging IR thermometer worked. As mentioned above, it can help to think of the TG165 as a combination thermal imager and infrared thermometer.

Some might point to the Flir One as an alternative, but the two products are designed for different uses. The Flir One thermal image quality should benefit greatly from MSX visual image contrast enhancement, a feature I absolutely love on my Flir E4, but the One also requires the display and processing power of an iPhone to operate. If you figure in the cost of an iPhone, the One and iPhone combination is priced in the same ballpark as the $1000 E4.

The Flir TG165 isn’t just about providing a decent resolution thermal image, but also provides a non-contact IR temperature reading with reasonably good accuracy.

I like what I’m seeing in the TG165, and although I plan for additional testing, I don’t think there will be anything to change my mind.

One worry I have is that some users will try to treat the TG165 as they would a true fully-featured thermal imaging camera, and that would be a mistake. It does not offer quite the same level of image control, nor does it offer quantitative temperature measurements aside from those acquired through the IR thermometer.

Overall, I like that the TG165 is true to what it tries to be – an imaging IR thermometer. It is compact, lightweight, and sturdily built. The $499 price point should make the TG165 very appealing to professionals who normally use IR thermometers for their temperature testing, measuring, and inspecting tasks.

If you want a better product, be prepared to step up to the $1000 Flir E4. But, to date, the TG165 provides the best thermal imaging quality that I have seen at a sub-$1000 price point.

Thank you to Flir for providing the review sample unconditionally. Review samples are typically given away, donated, or retained for editorial and comparison purposes.