Mechanical Filter UA-0559 is interposed between an accelerometer and the mounting point on the test object in order to prevent the accelerometer from detecting high-frequency vibration. There are several instances where this may be desirable.
- Where measurements of low-frequency vibration, possibly at low levels, and high-level, high- frequency acceleration masks the low-frequency components because of preamplifier overload, distortion, lack of electronic filters, etc.
- Where the accelerometer’s resonance frequency is being excited by high-frequency vibration of a possibly insignificant level, causing wideband measurement errors and overloads. Using the mechanical filter would then increase the useful dynamic range of the measuring instrument by more than 20 dB
- Where the accelerometer could be subjected to transient shock levels beyond its maximum capability – the mechanical filter could prevent possible damage
- Where the measuring instrument has a high-frequency response in excess of that required and is not equipped with suitable low-pass filters. Vibration measurements with a wide-band sound level meter is a notable example of this case
- Where a specific cut-off frequency is required without the use of specially built electronic filters or elaborate tunable filters. For example, when measuring vibration as applied to the human hand, arm or body, the measuring range is normally limited to below 1000 Hz