Yokogawa EJX930A - Manual (Page 18)

<3. Parameter Setting>
3-8
IM 01C25R05-01EN
3.3.4 Units
Refer to the subsection 3.3.3 to call up the display.
Select the unit from displayed list as shown below.
(1) Unit list of differential pressure
mmH2O, mmH2O@68degF, mmHg, Torr, MPa,
kPa , Pa, mbar , bar , gf/cm2, kgf/cm2, inH2O,
inH2O@68degF, inHg, ftH2O, ftH2O@68degF, psi,
atm, hPa
Note that the Yokogawa default setting for the
standard temperature is 4°C (39.2°F). For the units
of mmH
2
O, inH
2
O, and ftH
2
O, the pressure varies
according to the standard temperature definition.
Select the appropriate unit with @68degF when a
standard temperature of 20°C (68°F) is required.
(2) Unit list of static pressure
mmH2O, mmH2O@68degF, mmHg, Torr, MPa,
kPa , Pa, mbar , bar , gf/cm2, kgf/cm2, inH2O,
inH2O@68degF, inHg, ftH2O, ftH2O@68degF, psi,
atm, hPa
(3) Unit list of temperature
degC , degF, Kelvin
3.3.5 Damping Time Constant Setup
Any number from 0.00 to 100.00 can be set for
the amplifier damping time constant of process
variables.
Refer to subsection 3.3.3 to call up the display.
Damping time constant is set as shown in the
following table at the factory when the instrument
is shipped, but in case of the option code /CE is
specified, the damping time constant is set as
specified in the order.
Process variables Factory default value
Differential pressure 2s
Static pressure 1s
External temperature 1s
NOTE
The damping time constant for the amplifier
assembly can be set here. The damping time
constant for the entire transmitter is the sum of
the values for the amplifier assembly and the
capsule assembly.
About the value for the capsule assembly, refer
to the User’s Manual for EJX910/EJX930
(IM 01C25R01-01E) or General Specifications
(GS 01C25R01-01EN, GS 01C25R04-01EN).
3.3.6 Differential Pressure Signal Low Cut
Mode Setup
Low cut mode can be used to stabilize the
differential pressure output signal near the zero
point. The Low cut is applied to the differential
pressure used to flow calculation. The low cut point
can be set from 0 to 20% of output. (Hysteresis for
the cut point: ±10% of the cut point )
Follow the procedure below to change the Low cut
mode and Low cut point.
• Procedure to call up the display
[Root Menu] → Basic setup → Others →
→ Low cut Set from 0 to 20% of output
→ Low cut
mode
Select “On” or “Off”
(%)
50
(%)
50
0
50
(%)
50
(%)
DP
Output
DP
Output
For low cut in Off mode
Input
20 20
0
For low cut in On mode
Input
F0303.ai
Figure 3.2 Low Cut Mode
The low cut point has hysteresis so that the output
around the point is behaved as below figure.
<Example>
Low cut mode: On
Low cut: 20.00%
F0304.ai
Setting range: 0 to 20%
2% 2%
0%
DP Output
Low cut point
Input
Hysteresis
fixed at 10%
of the cut point
20%
3.3.7 Impulse Line Connection Orientation
Setup
This function reverses the impulse line orientation.
This function is used when the high pressure side
impulse line and the low pressure side impulse line
are connected reverse by mistake.
Follow the procedure below to assign the high
pressure impulse line to the L side of the transmitter.