KROHNE CARGOMASTER - Manual (Page 36)

CARGOMASTER®5
Operators Manual - 36
Zero adjustments
Tank pressure sensors
To ensure optimal accuracy, it is recommended that the sensors are zero
adjusted immediately before loading, whenever possible.
The following requirements apply:
• To zero adjust any Inert Gas Pressure (IGP) sensors, the tank must be open
to air.
• To zero adjust any bottom or upper sensors, the sensors cannot be
submerged in fluid.
• Temperature elements do not normally need zero adjustment.
• The atmospheric (reference) sensor should NOT be adjusted!
During the optimization, the user will be prompted to confirm that the tank is
really empty or open if:
• The pressure on the top sensor exceeds ± 100mmH2O
• The pressure on the upper, mid or bottom sensor exceeds ± 200mmH2O
CARGOMASTER® has a record of the last 20 adjustments made to the
sensor, and these values will be taken into consideration when optimization is
performed. The resulting value for the sensor may be slightly different from 0.
The zero setting is performed from the Zero Set layer in the ValueTable. The
pressure, offset and gain values are displayed here by default. Enter the value
to adjust to (usually 0) in the corresponding pressure field.
A whole group of sensors may be adjusted by entering the value in the Sum
field for the corresponding column. (The gain values can only be adjusted
from the configuration program)
Temperatures can be adjusted in the range 0-50 degrees Celsius, and only
maximum in ± 5-degree steps. (Adjustments in the range 50C + can only be
performed from the configuration program)
Line sensors
Adjustments on line pressure sensors are performed from the Line Pressure
view (SHIFT+F4). Zero setting may be performed if the displayed value is
within ±0,3 bar (± 3059 mmH2O). If the pressure exceeds ±0.3 Bar the
operator will be asked to confirm that the line is open /depressurized.
Vapor sensors
Adjustments on vapor pressure sensors are performed from the Vapor Pressure
view (CTRL+F4). Zero setting may be performed if the displayed value is
within ± 100 mmH2O. If the pressure exceeds ±100 mmH2o the operator will
be asked to confirm that the line is open /depressurized.