WILLMORE SEISMOMETER, 1960's

The Willmore Seismometer is a device for measuring earth tremors and was developed by Doctor P.L.Willmore, 1921-1994, who was for many years in charge of seismological operations at the British Geological Survey organisation (BGS) in Edinburgh, for which this instrument bears his name. Inside is a large magnet suspended around fixed coils, and works very much like a moving coil microphone but in reverse, here the magnet moves instead of the coil, the coils are monitored by an amplifier and the voltages created are recorded on a Chart Recorder. This is just the sensing part of the system. It is quit heavy weighing 20.5 lbs, almost 9.3 Kg. The unit may be placed upright or horizontal, and, the suspension is designed to compensate for both positions, in the picture the large magnet can be seen as the black mass in the middle of the unit, inside are two coils, one at the each end of the coil. The whole unit has been carefully designed to meet all types of earth tremors through calibration.

Donated by Tracy Nunn

Your comments:

• My late dad worked for BGS and we knew Pat Willmore personally. I remember these instruments well, having been present (as a child) at many installations here in Scotland and in Brazil in the 70s.
  Thank you for the memory!
  .......... Trevor Morgan-Edmond, Edinburgh, Scotland, 8th of October 2025
  
  

A1831