Infrared thermometers
Does a fixed 0.95 emissivity matter?
Both thermometers are 12:1, both cover roughly −50 to 600 °C (-58 to 1112 °F), and both read in half a second. One has emissivity adjustable from 0.10 to 1.00; the other is fixed at 0.95 and says so plainly. On matt surfaces they agree. On shiny metal they do not.
| Compared on | Infrared thermometer, −50 to 590 °C (-58 to 1094 °F) | Infrared thermometer, fixed emissivity 0.95 |
|---|---|---|
| Emissivity | Adjustable 0.10 – 1.00 | Fixed at 0.95 |
| Distance-to-spot ratio | 12:1 | 12:1 |
| Temperature range | −50 to 590 °C (-58 to 1094 °F) | −50 to 600 °C (-58 to 1112 °F) |
| Stated accuracy | Not published | Not published |
| Response time | Not published | Under 500 ms |
| Usable on bare metal | Yes, with emissivity set | No, without a matt patch |
| Batteries supplied | Not published | Two supplied |
| Listed on amazon.com | Yes | Yes |
A tick marks the better answer on that line only. Counting ticks does not decide the page — the two verdicts below do, because these products answer different questions.
Buy the Wintact if anything you measure is metal. Adjustable emissivity is the difference between a reading and a wrong number, and nothing on the instrument warns you when 0.95 is inappropriate.
Buy the KETOTEK for matt surfaces — cooking, radiators, plaster, plastic, wood — where 0.95 is close to correct anyway, and appreciate that it states its limitation instead of hiding it.
A patch of matt insulating tape on the shiny surface. The tape reaches the surface temperature and radiates like matt tape, which is close to 0.95 — so you measure the tape instead of the metal. It works with any thermometer.
Polished metal can have an emissivity below 0.1, and it reflects its surroundings rather than radiating. The error is large and always in the same direction: the reading is too low.
12:1 distance-to-spot · −50 to 590 °C (-58 to 1094 °F) · emissivity adjustable 0.10–1.00
A 12:1 infrared thermometer covering −50 to 590 °C (-58 to 1094 °F), with emissivity adjustable across the full 0.10 to 1.00 range — the setting that decides whether a reading on shiny metal means anything.
Best for: Anyone measuring metal, foil or glossy surfaces, where a fixed-emissivity thermometer is simply wrong.
≈ $19
12:1 · −50 to 600 °C (-58 to 1112 °F) · emissivity FIXED at 0.95 · under 500 ms
A −50 to 600 °C (-58 to 1112 °F) thermometer with a response under 500 ms, and an emissivity fixed at 0.95 — stated plainly, which makes clear what it can and cannot be pointed at.
Best for: Painted, plastered, plastic and organic surfaces — everything that is genuinely close to 0.95.
