IASPEI standard procedures for magnitude determination
These procedures address the measurement of amplitudes and periods for use in calculating the generic magnitude types: ML; Ms; mb; mB; and mb(Lg). A standard equation is also specified for Mw. For further details, please refer to the recommendations published by the IASPEI Working Group on Magnitudes (Magnitude WG).
Summary of the Magnitude WG recommendataions (pdf) - please refer to for seismometer responses referred to below and the Gutenberg and Richter (1956) attenuation function.