"Seismologists made direct measurements leading up to temblors by inserting sophisticated electrical probes one kilometer into the fault ★＜that＞ detected the tiniest stresses in rocks. " I can't translate this sentence into Japanese. I understand ★<that> is relative pronoun which stands for "probes". But I don't understand whether the probes detected the tiniest stress in rocks or not. Did these probes actually detected the tiniest stress in rocks?