Since this is an EN IEC standard, compliance allows manufacturers to sell their machinery globally, meeting CE marking requirements in Europe and similar standards in other regions.
The standard mandates precise measurement of the "dark-to-light" transition—how fast the device sends a stop signal once a beam is broken. en iec 61496
Safety of machinery – Electro-sensitive protective equipment Subject: Safety requirements and testing for light curtains, laser scanners, and safety radar systems. Since this is an EN IEC standard, compliance
[ S = K \times T + C ] Where: