Broadband, high gain instruments are calibrated using sine waves, step functions, and a random step function. Sine wave calibrations are done simultaneously on the N, E, and Z channels at 0.001, 0.02, 0.04, 1.0, 5.0 Hz. Step calibrations have positive step polarity and each channel is calibrated individually to verify connectivity and proper polarity. Random step calibrations are run simultaneously on the N, E, and Z channels.
Short period, high gain instruments are calibrated with step functions. Steps are positive polarity. Channels are calibrated individually for the same reasons as the broadband, high gain instruments. After step calibrating each individual channel, all channels are simultaneously calibrated with a positive polarity step function.
A table has been constructed to organize calibration infomation currently online. Notes on problematic calibrations are also available.