Complex sentence: The PPM was originally developed for use in AM radio broadcasting networks in the 1930s, independently in both Germany and the United Kingdom, as a superior alternative to earlier types of meter that were not good for monitoring peak audio levels.
Split into simpler sentences: The PPM was originally developed, independently in both Germany and the United Kingdom, for use in AM radio broadcasting networks in the 1930s. They are superior to earlier types of meter that were not good for monitoring peak audio levels.