1 Scope
This part of ISO 16063 specifies 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.
It is intended generally to be applied to a servo-type accelerometer with/without a velocity output, 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 specified enables the user 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 this method is 10−6 m/s2 (0,1 mGal). When the absolute gravimeter described in this part of ISO 16063 is used, the uncertainty of applied acceleration can be suppressed to 5 × 10−8 m/s2 (5 μGal). The relative expanded 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 is as follows:
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a) measurement and observation for the earth science including geophysics usage;
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b) measurement and observation for disaster prevention, such as detecting the precursor of a land slide;
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c) diagnosis for the soundness of a building structure and foundation soil in civil engineering;
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d) observation for nuclear-test detection.