ISO 2954:1975 pdf free

ISO 2954:1975 pdf free.Mechanical vibration of rotating and reciprocating machinery
If a vibration pickup designed for attachment to the object of measurement is used, this shall be affixed by a rigid mechanical connection, for example cementing, clamp-ing or screwing on or by means of a probe tip. No mechanical resonances of the rigid mechanical attachment or of the probe tip shall appear in the oper ating frequency band of the pickup.
For all types of attachment, the transverse sensitivity ratio shall be less than 0,1 over the whole measuring-frequency range.
The maximum level of vibration velocity for linear response of pickups shall be at least three times the vibration veloeity at fll-scale deflection in the sensitive direction.
To show the extent to which the vibration pickup affects the object of measurement, the effective mass of the vibration pickup shall be indicated in an easily visible manner on the vibration measuring instrument. To suit a wide range of applications, the mass shall be kept to the minimum possible.
NOTE- An indication of whether the mas of the pickup is too great can be obtained by the following method :
Double the co-wibrating mass of the pickup by an additional mass; if the new indicotion shows a deviation from the original reeding of more than 12%，the mass of the vibration pickup is too great as compared to the object of measurement and the result should be rejected.
The amplitude and frequency range of the vibration pickup shall be wide enough to avoid exceeding the permissible measurement error, as specified in 3.4.
The pickup shall withstand, without changing its characteristics, vibration in all directions of at least three times its specified maximum vibration input.
The equivalent input quantity of the self interference by hum and noise and the equivalent input quantity of the extraneous interference for interference fields and excitations with a magnitude as stated below shall not affect the measurement by more than 10 %. When the value depends on the orientation of the instrument in the field, the most unfavourable value shall be used.ISO 2954 pdf download.