testo 477 - LED stroboscope

Order-Nr.  0563 4770

  • Extremely high measurement range: up to 300 000 flashes per minute (fpm)

  • Very high illumination: up to 4800 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

Inspections and quality control of machines and systems, rotational speed measurements of hard-to-reach, small and fast-moving objects. And all while the machines are still running. No problem. No problem at all. With the testo 477 LED stroboscope.


Product Description

The testo 477 LED stroboscope makes stunningly fast movements look as if they are taking place in slow motion. This allows you to check and inspect machines and systems while they are still running, and measure speeds of up to 300 000 rpm.

It is impossible to tell with the naked eye if the thread guide of a knitting machine is working properly. It therefore equally impossible to tell if there are any irregularities in vibration or rotational processes of machines or systems. But it’s a different story with the testo 477 LED stroboscope. That’s because the stroboscope emits a series of flashes which 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. And because there’s no need for reflex marks, there’s no need to stop the machines and no disruption to production processes either.

LED stroboscope – technical features

An extremely high measurement range of up to 300 000 flashes per minute (fpm) and a very high illumination of up to 1 500 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 (which also allows it to 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.

What’s included

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 colour

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

LCD (Liquid Crystal Display)

Display size


Reverse battery protection


Low level

< 1 V

Maximum current

50 mA



ISO calibration certificate/rpm

Order Number: 0520 0012

DAkkS calibration certificate/rpm

Order Number: 0520 0422


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.