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iliasam / Laser_tape_reverse_engineering

Alternative firmware for a cheap X-40 laser tape measure
https://habrahabr.ru/post/327642
MIT License
121 stars 46 forks source link

Accuracy and Range Limits #4

Closed epsi1on closed 3 years ago

epsi1on commented 3 years ago

Can you please describe how much is Range limit of measured distance? The original laser meter is marked as 40m, but what about the new firmware? Can it measure distances more than 40m by prism reflectors?

Thanks

iliasam commented 3 years ago

Modulation frequencies are selected so that max range is 37.5m. If you need more, you have to change firmware. I'm not sure that you will get enough signal at such range with my firmware - it was designed for high speed measurements. Prism reflector or just reflective plate could probably help.

epsi1on commented 3 years ago

Thanks for information. The phase difference method for calculating the distance is also used on equipment named Total Station. In the advertisement they say in each KM with their own special prism there is a few millimeters error. image

What method do they use to first get a KM range, and also such good accuracy of mm?

Thanks heaps

iliasam commented 3 years ago

As I know, total stations could use low frequency (1-10 MHz) modulation for initial (not accurate) big distance measurement. After that, station is switched to high frequency mode to increase resolution. Of course, total station is based on high complex electronics, and have a lot of calibrations to get high precision.