Klein Tools TI290 Rechargeable Pro Thermal Imager with Wi-FI

Not directly on or near live circuits. The TI290 is not insulated and will not protect against electrical shock, so Klein's own warning is to never use it on or near live electrical conductors. In practice that means the panel cover stays on, or the work is done under the same PPE and safe-work procedures you would use for any other energized inspection task. The imager itself offers no shock protection.

The measurement range runs -4 to 752 degrees F (-20 to 400 degrees C). That covers refrigerant lines and cold spots at the low end and most steam piping, flue and boiler surface work at the top. You can also set high and low temperature alarms anywhere in that same range so the unit flags a reading instead of you watching the screen.

Yes, emissivity. The TI290 lets you set it anywhere from 0.01 to 0.99. Bare shiny copper and polished metal are low-emissivity and will read far cooler than they really are if you leave the setting at a default painted-surface value. The standard field fix is to set emissivity to match the surface, or put a piece of electrical tape or flat paint on the target and read that instead.

The sensor is 49,152 pixels, displayed on a 3.5 inch TFT LCD at 480 x 320. For building envelope work, missing batt insulation, thermal bridging at studs, wet drywall and radiant loop tracing, that resolution reads the broad patterns clearly. Where it gets thin is small targets at distance, like a single terminal across a wide switchgear room, because each pixel covers more area the further back you stand. For that kind of work you want to get closer rather than assume the camera will resolve it.

Images transfer over Wi-Fi to a free companion app on Google Play or the App Store, so you can pull a scan onto a phone or tablet at the truck and attach it to a work order or condition report the same day. Onboard memory holds 10,000 images, which is enough to run a full building survey before you offload anything. Charging is over USB-C.

The kit includes the thermal imager itself, a USB-C charging cable, a molded soft-storage case with a carabiner, and the instructions. The lithium-ion battery is built in and rechargeable, so there are no cells to buy. Nothing else is needed to start scanning apart from the free phone app if you want Wi-Fi image transfer.

It is a pocket-class instrument at 7.5 oz (213 g), with an ABS housing and a body measuring 4.48 x 3.1 x 1.06 inches. Klein rates it for 6.6 foot (2 m) drop protection, which covers a fall from a step ladder or off a panel ledge. The included soft case has a carabiner so it can hang off a bag or belt loop rather than ride loose in a pouch.

No laser sighting on this one. Targeting is done on screen instead, using crosshairs that report the temperature at the center point plus automatic high and low temperature spots in the frame. Field of view is 55.6 degrees plus or minus 2.8, which is wide, so on a small target you will want to close the distance rather than rely on a spot marker to tell you what is in the frame.

It is built for still capture, not video. Frame rate is under 9 Hz, which is the standard export-friendly refresh for handheld imagers and is fine for walking a panel or scanning a wall, but it will smear if you pan quickly or try to track something moving. The workflow is: settle on the target, let the image stabilize, capture the still, then transfer it over Wi-Fi.

Three palettes are available: ironbow, rainbow, and grayscale. Ironbow is the usual choice for electrical and mechanical hot spot hunting because heat reads as bright against a dark field and photographs well in a report. Rainbow spreads a narrow temperature band across more colors, which helps on building envelope and moisture work where the differences are only a few degrees. Grayscale is the cleanest for seeing fine structural detail without color banding confusing the picture.

The TI290 carries CE and UKCA marking, which covers sale and use in the EU and the UK respectively.