||The maximum rate at which an instrument’s output can be changed by some stated amount.
||A statistical term; the square root of the variance, i.e. the square root of the mean of the squares of the deviations from the mean value.
|Steady state vibration
||Periodic vibration for which the statistical measurement properties (such as peak, average, RMS and mean values) are constant.
|Step Stress Test
||A test consisting of several stress levels applied sequentially for periods of equal duration to a sample. During each period a stated stress level is
applied and the stress level is increased from one step to the next.
||A modern electronics production tool for precipitating latent defects such as poorly soldered connections. Utilizes random vibration and temperature
||A sinusoidal quantity having a frequency that is an integral sub multiple(X1/2,X1/3) of a fundamental (X1) frequency.
||Selecting or altering test procedures, condition, values, tolerance. etc., to simulate or exaggerate the environmental effects of one or more forcing
|Transducer (or pickup or sensor)
||A device which converts some mechanical quantity into an electrical signal.
||In steady state vibration, Tr is the non dimensional ratio of response motion/ input motion. two displacements, two velocities or two accelerations.
The maximum Tr value is the mechanical ‘Q’ of a system. At resonance, Tr is maximum.
||Mechanical oscillation or motion about a reference point of equilibrium.
|Vibration machine (or exiter or shaker)
||One which produces controlled and reproducible mechanical vibration for vibration testing mechanical systems, components, or structures.
||An apparatus ( usually an electronic amplifier, detector and readout meter) for measuring electrical signals from vibration sensors. May read \
displacement velocity and /or acceleration.
|Wear-out Failure period
||That period during which the failure rate of some items is rapidly increasing due to the deterioration processes.