Second step: Vibration testing

The starting frequency is set at 5 Hz and increases at a rate of 2 octaves per minute until reaching the set point. This test is inspired from MIL-STD-883J (Method 2005.2). The software automatically tunes the increase of g, since the physical limitation of the apparatus does not allow displacements big enough to reach the acceleration set point at low frequencies. 
The definition of a sweep is a logarithmical round trip from 5 Hz to either 2,000 or 2,400 Hz -- and back again to 5 Hz following the same path. The duration of a single sweep is 8 minutes and 30 seconds. It is important to point out that vibration testing in the MEMS-REAL study never managed to show any failure in the accelerometers produced by Murata. During the present study, no failure after vibrations testing was also recorded.

Third step: Mechanical shocks (response)

The first and second steps have been scaled so that 100% of the samples survived until this third step. The number of shocks necessary to reach total failure were known from the previous MEMS-REAL tests and used as comparison (Figure 5).