WIKA PGT43.100 - Manual (Page 17)

GB
9. Service and maintenance
Slotted
screw
11
97
64 05/
009 GB/D/F/E
WIKA Operating Instructions intelliGAUGE family 17
9. Service and maintenance
Always open isolating devices gently, never abruptly, since this may generate
sudden pressure surges that may damage the gauge. The maximum working
pressure for pressure gauges with transmitters is indicated by the limit marks
on the dial.
With fluctuating pressure loads, lower values apply in accordance with EN 87.
The pressure gauges with transmitters require no maintenance and feature a
long service life if handled and operated properly. As a result of the mechanical
loading, and depending on the service conditions, it may become necessary to
check and readjust the zero point of the transmitter.
Zero point test
Normally the zero point is checked and adjusted in an unpressurised state. The
zero point of differential pressure gauges with transmitters should be checked
and adjusted by opening the pressure compensating valve under static load.
Mechanical zero point (pointer) 1)
If the pointer deviates from the zero point (in the unpres-
surised condition), the zero point may be corrected by
means of the integrated adjustable pointer. To do this,
remove the bayonet ring, including the window and seal,
from the housing. The zero point is altered by turning the
adjusting screw on the adjustable pointer.
After correcting the zero point, fasten the bayonet ring
and the window with its seal and then close the pressure
compensating valve or open the stop valve.
Electrical zero point (4 mA) 1)
If the mechanical zero point is changed by means of the adjustable pointer, the
electrical zero point must be reset to the mechanical zero point.
First depressurise the pressure gauge.
Loosen the complete cable hood on the right-hand side of the pressure gauge
by completely unscrewing the screw  on the top of the cable hood cover 
using an appropriate screwdriver (0.6 x .5 mm).
1) Not model PGT.06