The amount of signal loss from a fiber splitter is usually measured by its insertion loss, measured in decibels (dB). Insertion loss refers to the signal strength loss caused when the splitter distributes the input signal to the output port, that is, the difference between the input signal power and the output signal power. In general, the insertion loss of a PLC splitter will vary between different specifications and manufacturers, but its typical value is usually around 3-5dB.