Seismic scanner
From Tardis Wiki, the free Doctor Who reference
The seismic scanner was a component of the Doctor's TARDIS which signalled seismic activity outside the ship, such as on the volcanic planet Sarn. (TV: Planet of Fire)
Previously, the TARDIS had signalled seismic activity on Skaro, but it was not specified as the work of the seismic scanner. (TV: Destiny of the Daleks)
