6.1
Determining offset pressure
The digital pressure gauge has a low offset.
¶
To determine this offset the preselection for the test
pressure should be set to a minimum, to do so turn
the controller (Fig. 7, Pos. 4) in an anti-clockwise
direction up to the stop. Set the three-way switch
(Fig. 7, Pos. 6) to measuring pressure <P2>.
i
The pressure then shown is to be added to the
measured/applied pressure, which is quoted in the
Service Instructions, in order to enable the deviation
in the measurement to be compensated for.
Adjusting applied pressure <P1>:
Set three-way switch (Fig. 7, Pos. 6) to the position
P1 <Application pressure>. On the controller (Fig. 7,
Pos. 7) the application pressure is now adjusted, it
can then be read off on the display (Fig. 7, Pos. 5).
The applied pressure can be used to move the actu-
ated pneumatic cylinder into the correct reference po-
sition before the measurement.
Adjusting measuring pressure <P2>:
Set the three-way switch (Fig. 7, Pos. 6) to position
P2 <Measuring pressure>. On the controller (Fig. 7,
Pos. 4) the measuring pressure is now set, it can then
be read off on the display(Fig. 7, Pos. 5).The previous-
ly-determined offset pressure must then be added to
the set measuring pressure. The measuring pressure
can be used to generate an exactly-defined measuring
force in the pneumatic cylinder, the tolerance here is
<+/- 1N>.
i
Optimum measuring results can only be achieved in
combination with suitable measuring devices, e.g.
Bosch components for the repair of Bosch common-
rail injectors with solenoid valve (see example 2,
Fig. 4).
Return pressure <P0>:
!
To relieve the measuring device and to pull back the
pushrod, the cylinder on the measuring device has
supply pressure <P0> applied to it. In a state of rest
the direction reversal is set to <P0>, the cylinder is in
the raised, reversed basic position.
Robert Bosch GmbH
Operation | CRR 120 | 15
7.
Troubleshooting
7.1
The CRR 120 cannot be switched on
Possible faults:
The CRR 120 is not being operated with the operating
voltage of 24 V (DC), or the voltage regulator on the
voltage stabilizer is not set to 24V.
The CRR 120 has been connected with the polarity
mixed up. The compressed-air supply is not stable or
the input pressure is too low (< 6.5 ... 7 bar) / not avail-
able.
7.2
The applied pressure and/or the
measuring pressure cannot be
adjusted
Possible faults:
The CRR 120 is not being operated with the operating
voltage of 24 V (DC), or the voltage regulator on the
voltage stabilizer is not set to 24V.
The controllers for the applied or measuring pressure
have been locked.
en
|
0 986 629 504
2020-08-24