Complex sentence: Their instrumentation worked well during a mock test explosion of 100 tons of TNT, which was detonated two months beforehand, but no information was obtained during Trinity, because an unexpected rain shower the night before soaked the apparatus.
Split into simpler sentences: Their instrumentation worked well during a mock test explosion of 100 tons of TNT, which was detonated two months beforehand. However, no information was obtained during Trinity, because an unexpected rain shower the night before soaked the apparatus.