Guralp Systems CMG-5TD - Manual (Page 34)

CMG-5TD Digital Accelerometer Calibration
7. Hold down SHIFT and drag across the window to select the calibration
signal and the returning component(s). Release the mouse button,
keeping SHIFT held down. A menu will pop up. Choose Broadband
Noise Calibration.
8. This runs a script, bbnoisecal, which prompts you for sensor
calibration parameters for each component you have selected.
MAN-050-0005 34 Issue D - April 2013