BRUEL & KJAER System V - Push Rods

Fig .3.6. VIbration testing of an electronic measuring instrument
where mF is the mass of the fixture and 10 m/ s
2
is approximately the gravitational ac-
celeration . The force necessary to drive the test object, fixture and moving element is:
FDRIVE = (0,5 + 0,45 + mF) 100 = 95 + 100mF
The maximum specified force available for the 4805 / 4812 combination is 3 12 N. The
drive equations can therefore be stated as:
FDRIVE = 312 - = 312 -5 -10mF
Combining the two equations,
307 -10mF = 95 + 100mF
110 mF = 212
mF = 1,93 kg
F
LlFT
3.9. PUSH RODS
Since the Mode Study Head has a central point through which all its force is directed and
since it is usually more convenient to have the driving point a short distance from the
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