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Review

testo 871s Review: 240×180 Thermal Imaging With App Connectivity

The testo 871s sits between the 868s and 872s: more pixels than the entry model, the same assistance functions and app, and a lower price than the 320×240 flagship. This review explains what the 240×180 detector changes and where to buy it, since it is not on Amazon US.

By the Akermin Editorial Team · 4 min read

As an Amazon Associate, Akermin earns from qualifying purchases. Product links on this page are affiliate links.

Verdict

The testo 871s is the model to choose when the 868s’s 160×120 detector is the only thing holding it back. testo documents a 240×180 detector with SuperResolution to 480×360, the same thermal sensitivity class as its siblings, and the same assistance functions: ScaleAssist, the IFOV warner, automatic hot and cold spot marking, an integrated visible camera and the Thermography App for reports. It is not currently listed on Amazon US, so this review is based on testo’s documentation and on the listed 868s as the closest reference. For a building surveyor or maintenance electrician who wants more pixels without paying for the 872s, it is the sensible middle option.

What Is Different Across the Range

Item testo 868s testo 871s testo 872s
Detector 160×120 240×180 320×240
SuperResolution 320×240 480×360 640×480
Measurement pixels 19,200 43,200 76,800
ScaleAssist, IFOV warner, hot/cold spot Yes Yes Yes
Visible camera and app Yes Yes Yes
Amazon US listing Listed Not currently Not currently

What 240×180 Buys

Resolution in thermography is about distance and target size. With 43,200 pixels the 871s measures a target of a given size from roughly one and a half times the distance of the 868s, or resolves a target two-thirds the size from the same distance. On a building survey that means a whole facade in one frame with enough detail to see individual window reveals; in a plant room it means reading a terminal on a contactor without opening the enclosure door wider than necessary. SuperResolution to 480×360 makes the displayed image correspondingly sharper. Our guide to comparing thermal camera resolution explains how to translate detector size into working distance.

The Assistance Functions

The 871s inherits the functions that distinguish testo’s handhelds. ScaleAssist fixes the display scale from entered indoor and outdoor temperatures so that images from a survey are directly comparable. The IFOV warner shows the smallest measurable spot at the current distance. Hot and cold spot detection marks the extremes automatically. The integrated visible camera records a matching photograph for reports. These are the same on the 868s, so the decision between the two really is about detector size alone.

App and Reporting

The testo Thermography App connects to the 871s for live view on a phone or tablet, on-site analysis and PDF reports. For larger surveys, testo’s desktop software handles batches of radiometric images. Owners of testo handhelds describe the software as functional rather than elegant; the strength is that every image carries the scale, emissivity and reflected temperature settings, which is what makes a report defensible. See setting emissivity for why those settings matter.

Availability

Because the 871s is not on Amazon US, it is bought from testo directly or from instrument distributors, often as a kit with a case and sometimes with a calibration certificate. Buyers should confirm the current specification and warranty from testo, and compare the distributor price against the listed 868s and the 860i before deciding. For most building-diagnostics buyers the 871s is the sweet spot of the three; for those who mainly inspect at close range, the 868s does the same job for less. A useful way to decide is to list the three or four targets you photograph most often and the distance you can stand from each. If any of them is a small target at more than a few metres, such as a busbar connection in a switchroom or a flat-roof detail from the ground, the 871s pays for itself on the first report; if every target is a wall or a panel within arm’s reach, it does not. Our guide to choosing a thermal camera for home inspection covers the residential end of that decision.

Strengths

  • More than double the measurement pixels of the 868s.
  • Same assistance functions and reporting workflow as the rest of the range.
  • Integrated visible camera.

Limitations

  • Not currently listed on Amazon US.
  • Fixed focus.
  • Higher price than the 868s for the same functions.

How It Compares

The testo 868s is the listed, lower-cost sibling. The testo 872s adds 320×240 for professional inspection at distance. The testo 860i offers a 256×192 detector in a wireless phone-connected format at a lower price than the handhelds. The FLIR E5 Pro is the FLIR alternative at the 160×120 level with cloud upload.

How We Research

This review is based on testo’s published specifications for the 871s and the rest of the handheld range, the Amazon listing for the 868s as the closest listed model, and owner reports. We did not run laboratory tests. Buyers should verify current specifications with testo, since the model is not on Amazon US.

Testo 868s Thermal Imager – High-Resolution Thermal Camera with 160 x 120 px - Integrated 5 MP Camera and App-Operation – Thermal Images with Automatic Hot and Cold Spot Detection

Testo 868s Thermal Imager – High-Resolution Thermal Camera with 160

View on Amazon
testo 860i Wireless Thermal Imaging Camera Set for iPhone & Android - Thermal Imager with Carrying Pouch & USB-C Cable - Handheld Infrared Camera 256 x 192 Resolution & -4 to +662 °F Measurement Range

testo 860i Wireless Thermal Imaging Camera Set for iPhone &

View on Amazon

Products shown because their documented specifications fit this guide. Price and availability are on Amazon and can change.

Frequently Asked Questions

Is the testo 871s on Amazon?

Not on Amazon US at the time of writing. The 868s and the 860i are the testo thermal cameras listed. The 871s is sold through testo and instrument distributors.

How much better is 240×180 than 160×120?

It is 43,200 measurement pixels against 19,200, more than double. In practice you can measure a target of the same size from about one and a half times the distance.

Does it have the same functions as the 868s?

Yes. testo documents ScaleAssist, the IFOV warner, hot and cold spot detection, a visible camera and the Thermography App across the 868s, 871s and 872s.

Which should I buy, 871s or 872s?

The 872s has 320×240 and is aimed at professional inspection from distance. The 871s is the better value for building work and close-range electrical inspection.

Affiliate disclosure: Akermin earns a commission from qualifying Amazon purchases made through links on this page. Our editorial picks are based on documented specifications and owner feedback, not commissions.