scope:

This International Standard prescribes the instrumentation and procedure to be used for the accurate calibration of seismometer sensitivity using local gravitational acceleration (local Earth's gravitation; local value for the acceleration due to the Earth's gravity) as a reference value. This International Standard should generally apply to a servo-type accelerometer with/without a velocity output, as which usually has a mass position output, in the category of a wide-band seismometer with a bandwidth from 0,003 Hz to 100 Hz. The method described in this International Standard enables the users to obtain static sensitivity for the seismometers up to 10-5 m/s2 (which corresponds to 1 mGal and approximately 1 ppm of the gravitational acceleration). The combined and expanded (k=2) uncertainty of applied acceleration achieved by these methods is 10-6 m/s2 (0,1 mGal). When the absolute gravimeter described in this document is used, the uncertainty of applied acceleration can be suppressed to 5 x 10-8 m/s2 (5 ìGal). The relative uncertainty of calibration, excluding the uncertainty due to the device under test (DUT), is 0,5 %. The intended end-usage of the seismometer to be applied in this standard is as follows. a) Measurement and observation for the earth science including geophysics usage; b) Measurement and observation for the disaster prevention, such as detecting the precursor of a land slide; c) Diagnosis for the soundness of a building structure and foundation soil in the civil engineering; d) Observation for nuclear-test detection.