WIKA 851.02.100 - Manual (Page 8)

WIKA Operating instructions DELTA-plus, DELTA-comb and DELTA-switch 8
Differential pressure
is zero Differential pressure
is measured again
Released
Valve button
pushed
308
15 07/
009 GB/D/F
GB
6.3 Setting the switch point / checking the zero point
The
switch points are set at the factory when the desired values are given. The
adjustment of the switch point is made by setpoint screws accessible from the
front. The assistant scales enable a relatively accurate adjustment of the switch
points over 70 p° and indicate the setpoint that is momentarily adjusted.
For contact re-adjustment the snap-fit window is to be lifted off using a screw
driver at the recess in the circumference. The desired switch point can be set
by turning the contact adjustment screws with a screw driver.
If a more accurate switch point adjustment is desired, a test variable should be
used.
Afterwards press the window back into the case.
To
check zero point see below
7. Options and accessories
7.1 Integrated pressure equalising valve
The
zero point check during the working
process is enabled by pushing the valve
button. The measuring medium flows from
the higher pressure side to the opposite
side and the differential pressure drops to
zero.
st
and sv:
When the valve button is pushed, the differential pressure pointer must move
into the range of the zero point tolerance bar. As a consequence the function
of the instrument is in order. In the case of possible deviations beyond the
tolerance bar a zero point correction can be made via a standard integrated
adjustment pointer. For that purpose the snap-fit window
is to be lifted off using a screw driver at the impression/
recess in the circumference. The zero point is corrected
by turning the slotted screw at the adjustment pointer.
Afterwards the window is to be snap-fitted to the case
again. The differential pressure is indicated again, as soon
as the valve button is released.
6. Commissioning / 7. Options and accessories
Slotted
screw