IRIS provides management of, and access to, observed and derived data for the global earth science community.
This includes ground motion, atmospheric, infrasonic, magnetotelluric, strain, hydrological, and hydroacoustic data.
IRIS facilitates seismological and geophysical research by operating and maintaining open geophysical networks and providing portable instrumentation for user-driven experiments.
Instrumentation support includes engineering services, training, logistics, and best practices in equipment usage.
All data collected with IRIS instrumentation are made freely and openly available.
Our mission is to advance awareness and understanding of seismology and earth science while inspiring careers in geophysics.
IRIS is a consortium of over 125 US universities dedicated to the operation of science facilities for the acquisition, management, and distribution of seismological data, and for fostering cooperation among IRIS members, affiliates, and other organizations in order to advance seismological research and education.
From what I know these sensors have flat amplification from DC values to