This model is a K2 made by Kinemetrics and part of the PacificNorthwestSeismographNetwork.
A seismograph is also sensitive to changes in temperature, and many instruments are constructed from low expansion materials such as nonmagnetic invar.
A Kinemetrics seismograph, formerly used by the United States Department of the Interior.
The PNSN is operated jointly by the University of Washington, the University of Oregon, and Oregon State University, and is funded by the U.S. Geological Survey, U.S. Department of Energy, and the State of Washington.
PNSN data help scientists understand PacificNorthwest earthquake hazards, predict volcanic eruptions at Mount St. Helens, and determine the location of faults and volcanic magma chambers.
The PNSN is developing the capability to detect the earliest earthquake signals arriving at the coast and immediately broadcast warnings to tsunami warning centers.