Unlike traditional seismometers, which detect ground motions through their effect on weights hanging from springs, the precision laser inclinometer (PLI) measures their effect on the surface of a liquid, CERN Updates.
Sensor used at CERN could help gravitational-wave hunters
Sensor used at CERN could help gravitational-wave hunters
Sensor used at CERN could help gravitational-wave hunters

The PLI (bottom two plots) picked up the same signals as devices already installed at Virgo (top two plots) for an earthquake in Northern Italy on 17 August (Image: Beniamino Di Girolamo/CERN)