Document ID: chunk:federal_register_of_legislation:F2005L03990:front:0:p26
Version: federal_register_of_legislation:F2005L03990
Segment Type: other
Provision Reference: 
Character Range: 64652–67351

The errors shall be less than ± 1.5 per cent of the channel amplitude class.
2.6.2.1.2. Forces
 The error shall be less than ± 1 per cent of the channel amplitude class.
2.6.2.1.3. Displacements
 The error shall be less than ± 1 per cent of the channel amplitude class.
2.6.2.2. Dynamic calibration
2.6.2.2.1. Accelerations
 The error in the reference accelerations expressed as a percentage of the channel amplitude class shall be less than ± 1.5 per cent below 400 Hz, less than ± 2 per cent between 400 Hz and 900 Hz, and less than ± 2.5 per cent above 900 Hz.
2.6.2.3. Time
 The relative error in the reference time shall be less than 10-5.
2.6.3. Sensitivity coefficient and linearity error
 The sensitivity coefficient and the linearity error shall be determined by measuring the output signal of the data channel against a known input signal for various values of this signal. The calibration of the data channel shall cover the whole range of the amplitude class. For bi-directional channels, both the positive and negative values shall be used. If the calibration equipment cannot produce the required input owing to the excessively high values of the quantity to be measured, calibrations shall be carried out within the limits of the calibration standards and these limits shall be recorded in the test report.
 A total data channel shall be calibrated at a frequency or at a spectrum of frequencies having a significant value between FL and FH/2.5.
2.6.4. Calibration of the frequency response
 The response curves of phase and amplitude against frequency shall be determined by measuring the output signals of the data channel in terms of phase and amplitude against a known input signal, for various values of this signal varying between FL and 10 times the CFC or 3,000 Hz, whichever is lower.
2.7. Environmental effects
 A regular check shall be made to identify any environmental influence (such as electric or magnetic flux, cable velocity, etc.). This can be done for instance by recording the output of spare channels equipped with dummy transducers. If significant output signals are obtained corrective action shall be taken, for instance by replacement of cables.
2.8. Choice and designation of the data channel
 The CAC and CFC define a data channel.
 The CAC shall be 1, 2 or 5 to a power of ten.
3. MOUNTING OF TRANSDUCERS
 Transducers should be rigidly secured so that their recordings are affected by vibration as little as possible. Any mounting having a lowest resonance frequency equal to at least 5 times the frequency FH of the data channel considered shall be considered valid. Acceleration transducers in particular should be mounted in such a way that the initial