To determine the Planck constant "h" with LEDs (inner photoelectric effect).
If voltage is applied on an LED, the breakdown voltage can be ascertained through the flash (or with an mA meter).
This is characteristic but differs because of the wavelength (colour) of the diode.
The Planck constant "h" can be determined by means of the wavelength of the diode and the breakdown voltage.
6 plug-in blocks (PIB) with diodes of different wavelengths:
405 nm (light blue)
465 nm (azure)
565 nm (green)
585 nm (yellow)
660 nm (signal red)
870 nm (IR)
1 plug-in block (PIB) current limiter 10µA
Can be used on P3910-1A plug-in panel or as an addition to the P9901-4D SEK Electricity 1