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C-BEEPER detekuje kapacity od jednotek pF do stovek nF. Čím menší je kapacita na vstupu tím vyšší tón produkuje.

C-BEEPER is capacitance detector and will detect as little as 3 pF and oscillate at frequencies from kHz to fractional Hz.

http://blog.ok1cdj.com/2012/02/c-beeper.html

http://www.vk2zay.net/article/266