Pressure Pulse Generator
6909_002-173e-02.22Page 8
4.3 Location
To obtain ideal operation, i.e. max. pressures, shortest
pulse duration and good recoil of the drop weight, the
pressure pulse generator must be set up on a at and
hard base (e.g. steel plate, concrete oor).
Good recoil allows the weight to be caught again with the
hand after the initial impact on the piston.
4.4 Performing drop tests
The pressure generated is not proportional to the drop height,
i.e. even very low drop heights produce high pressure, and
the pressure rises only slightly with increasing drop height.
It is therefore advisable to begin testing with very low drop
heights and gradually to increase the drop height.
If pressure sensors with a pressure range of < 5 000 bar are
used, there is a danger when using the drop weight (5,4 kg)
that the permissible pressure range will be exceeded and the
sensors damaged beyond repair.
Pressure sensors with a pressure range of < 500 bar must not be
tested with the drop weight 5,4 kg but only with the aluminum rod.
With pressure sensors with a pressure range of up to 250 bar,
testing must be started with a drop height of not more than 5 cm.
4.5 Exchanging the adapter
Unscrew the 4 hexagonal slot screws M4 at the base
of the drop tube.
Remove drop tube and drop weight.
Unscrew the 4 hexagonal slot screws M8.
Remove the drop tube base
Withdraw the piston-cylinder unit from the adapter.
Fit new seal Type 1101B in the adapter and push
together with the piston-cylinder unit. It is advisable
to apply a light lm of grease to the tting surface to
increase adhesion between the parts.
Slide the piston up to the limit stop in the adapter.
Then t the adapter and piston-cylinder unit onto the
intermediate adapter.
Place the drop tube base in position, screw in the
4 x M8 hexagonal slot screws by hand and then
tighten them with the wrench in stages by tightening
opposite pairs of screws in turn until all screws are
fully tightened.
Fit the drop tube and screw in position.