Tiltmeters

Attached to the bridge are two BDI T500 Tiltmeters that measure the rotation of the South Tower of the Memorial Bridge, that is the tower closest to Portsmouth. By comparing the data of the tiltimeter at the top and bottom of the tower, the rotation of the tower during lift events can be found. One is attached to the top of the tower and one to the bottom. The unit is accurate to +3° in arclength.