testo 477 - LED stroboscope

Order-Nr.  0563 4770

  • Very high measurement range (up to 300,000 flashes per minute)

  • Very high illumination (up to 1500 Lux)

  • Long operating times (battery power for up to 5 h)

  • Trigger input and output (for connectivity to external systems and control via external sensor)

The testo 477 LED stroboscope allows you to perform inspections and quality control of machines and systems and rotational speed measurements on hard-to-reach, small and fast-moving objects while the machines are still running.


Product Description

The testo 477 makes stunningly fast movements appear as if they are in slow motion. For measuring speeds of up to 300,000 rpm and inspecting machines and systems while they are still running.

There is no way of telling with the naked eye if the thread guide of a knitting machine is working properly or if there is anything wrong or irregular about vibration or rotational processes of machines or systems while they are still running. The testo 477 LED stroboscope emits a series of high-speed flashes that makes what you see appear as a frozen image.

The testo 477 LED stroboscope can also measure the rotational speed of very small and hard-to-reach objects without having to first shutdown machines or disrupt production processes.

Technical features

A very high measurement range of up to 300,000 flashes per minute and a very high illumination of up to 1500 Lux allow you to carry out rotational speed measurements of up to 300,000 rpm. A trigger input and output ensure connectivity to external systems and control via an external sensor.

The LED stroboscope’s integrated impact protection and sturdy IP65 rated housing (can be wiped down) ensure that the testo 477 can stand up to the rough and tumble of everyday use. And thanks to a longer battery operating time, you can carry out uninterrupted measurements for up to 5 hours.

Delivery Scope

testo 477 LED stroboscope, carry case, trigger signal plug, calibration protocol, batteries.

Technical Data

rpm - LED

Measuring range

30 to 300000 fpm


0.02 % of mv


±0.1 (30 to 999 fpm)

±1 (1000 to 300000 fpm)

General technical data

Protection class


Flash duration

Can be adjusted

Flash intensity

4800 Lux at 6000 FPM / 30 cm

Flash color

Approx. 6500 K

Battery life

NiMH rechargeable battery: Approx. 11 h at 6000 fpm; Batteries: approx. 5 h at 6000 fpm (3 x AA)

Display type


Display size


Reverse battery protection


Low level

< 1 V

Maximum current

50 mA


Speed measurements on ventilators, fans, and lathes

The testo 477 allows the speed measurement of very small objects or places that cannot be directly accessed – without interrupting the production process, as reflective markers are not required.

Our powerful LED stroboscope testo 477 allows fast moving objects to appear in slow motion and determine the speed up to 300,000 revolutions per minute.

Industrial maintenance and monitoring of product quality

Using our testo 477 allows fast moving objects to appear in slow motion and conclusions to be drawn about rotational and vibratory movements. The “flashing light analysis” allows irregularities to be detected in systems and machines; for example, the detection of “vibration hotspots”, the monitoring of packaging machines, the checking of vibratory conveying technology, or the display of oscillation amplitudes.

With the aid of stroboscopes, rotating production systems and belts are presented in slow motion, allowing evaluation of the product and manufacturing quality. For example, the thread guide on knitting machines can be monitored in the textiles industry, or the consistent image quality of printing machines.