Quick verdict
A point-and-read infrared thermometer with a 10 to 1 distance-to-spot ratio and a targeting laser, reading from minus 4 to 752 F with fixed 0.95 emissivity and a backlit display with hold, for checking a cordless tool battery that feels warm after a fast charge, a charger that is working hard in a hot shed, a mower engine, a blade bearing or a compost core without touching any of them. Lithium batteries charged hot age fast and charged very hot are a hazard; a reading of the pack surface says whether to let it cool first. Klein makes electricians tools and this is their basic IR gun.
Strengths
- Reads surface temperature at a distance in a second
- Covers minus 4 to 752 F for batteries, engines, bearings and heaps
- Laser targeting and 10:1 spot ratio for a small target
- Backlit display with auto-hold
- Klein build quality
Weaknesses
- Fixed emissivity; shiny metal reads low
- Surface only; the inside of a battery pack is hotter than its case
- Not for people or animals, as the maker says
The overall YardToolLab Score is out of 100. Section scores are out of 10.
Is That Battery Too Hot to Charge?
A cordless battery straight off the trimmer on a hot afternoon is warm in the hand, and the question is whether it is warm or too warm to put on the charger. An infrared thermometer answers in a second without touching it. Klein’s IR1 is a laser-targeted IR gun reading from minus 4 to 752 F with a 10 to 1 spot ratio, which covers a battery pack, a charger, a mower engine and most of what gets hot in a yard.
This review is based on the maker’s specifications and on how infrared thermometers are used for equipment checks generally. We have not used this thermometer ourselves.
Batteries and Chargers
Lithium packs are meant to charge and work between about 40 and 105 F. A pack from a July trimmer or a fast charger in a closed shed can be far above that, and charging it hot ages it; a pack that is hot enough to be uncomfortable to hold is a pack to leave on the bench until it reads under 105 F on the case. The charger body is checked the same way, since a charger that is hot to the touch in a hot shed is working at the edge of its own limits. Point, read, decide.
Using It
Aim the laser dot at the target close enough that the measured spot is smaller than the target; at 10 to 1, from a foot away the spot is a little over an inch. Pull the trigger, read the backlit display, and the hold keeps the number after the trigger is released. Auto power off saves the battery.
Around the Yard
A mower engine shroud or a deck spindle that is running hotter than its neighbour, a pressure washer pump after a minute in bypass, the core of a compost pile from the side, a greenhouse bench under a heat mat, the asphalt before the dog walks on it.
Emissivity
The IR1 is fixed at 0.95, which suits plastic, painted metal, wood and soil. Bare shiny metal reflects and reads low; a strip of masking tape on the spot fixes that.
Build
Klein makes tools for electricians and the IR1 is their simple gun: solid case, clear display, no modes to misread. It is not a medical thermometer and the maker says so.
Who Should Buy It
- Owners of several cordless batteries charging in a shed.
- Anyone diagnosing a hot mower or washer.
- Composters and greenhouse growers reading heat without a probe.
Common Owner Complaints
Low readings on bright metal. Tape the spot.
Alternatives to Consider
An Etekcity IR gun for a cheaper tool. A probe thermometer for the inside of a compost pile. A thermal camera for a whole engine at once.
Verdict
For knowing whether a battery, a charger or an engine is hot or too hot, a point-and-read IR gun is the quick answer and the Klein is a solid one. Aim close, tape shiny metal and let a hot pack cool before it charges.
Full specifications
Klein Tools IR1 Infrared Thermometer with Targeting Laser, Auto-Hold, Minus 4 to 752 F FAQs
Lithium tool batteries should charge and be used between roughly 40 and 105 F. A pack straight off a trimmer in July or a fast charger in a hot shed can be well above that; charged or used hot, it loses life, and a pack that is very hot is a fire risk. Point, read, and let it cool if the case is over about 105 F.
Aim the laser at the target from close enough that the spot is smaller than the target, pull the trigger and read. At 10:1, a foot away reads a spot a little over an inch across.
A mower engine or a blade spindle that is running hot, a compost pile core from the outside, a greenhouse bench, a hot tub cover, a pressure washer pump in bypass.
Bright metal reflects rather than emits and reads low at 0.95 emissivity. A strip of tape on the surface gives a true reading.
