Push Rods - BRUEL & KJAER System V Instruction Manual

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 1 2 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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