Metso neles ND9000P, User Manual

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3.2.4.2 Dynamic Loop Test
Figure 14 shows Dynamic Loop test.
Figure 14. Dynamic Loop test
.
You can control the Dynamic Loop test by entering the fol-
lowing parameters in Dynamic Loop Test view:
ƒ Test Init Time : The time given to valve to reach the
starting point of the test
ƒ Ramp Time : Duration of ramp time. Total test time is
then Init Time + 2* Ramp Time
ƒ Start Position : Starting setpoint for test
ƒ End Position : Ending setpoint for test. Note that the
end setpoint may be smaller than the start setpoint. In
that case, the loop runs downwards in time.
You can start the test by clicking the "Start test" button. The
test can be stopped any time by clicking the "Cancel test"
button.
Once the test has been run, the following test results are
calculated.
ƒ Maximum Dynamic Error Band : The maximum dif-
ference in valve travel for any single setpoint value
during the loop. The value is calculated by the device
from the loop size minus 10% from the start and 10%
from the end.
ƒ Setpoint at max error (%) : The value of the setpoint at
the point at which Maximum Dynamic Error Band is
measured.
3.2.4.3 Valve Analysis Test
Figure 15 shows Valve Analysis test.
Figure 15. Valve Analysis test.
You can control the Valve Analysis test by entering the fol-
lowing parameters in Valve Analysis Test view:
ƒ Test Init Time : The time given to valve to reach the
0% position.
ƒ Ramp Time : Duration of ramp time. Total test time is
then Init Time + 4* Ramp Time + 2*Steady Time .
ƒ Start setpoint : Measurement point of hysteresis, a
position at which the valve stops for static hystereis
measurement.
ƒ Steady Time : Used to store the steady time in the
hysteresis position. This is also the amount of time in
that the test is held in the 100% position before the de-
scending ramp is started.
You can start the test by clicking the "Start test" button. The
test can be stopped any time by clicking the "Cancel test"
button.
Once the test has been run, the following test results are
calculated.
ƒ Static Hysteresis : During the steady time, the last 80
msec valve position is averaged in the opening ramp.
The same average is calculated while closing the
valve. The hysteresis is the difference of these values.
ƒ Sensitivity : A percentage of change in input signal that
is measured when the valve starts moving again after
the steady state of the opening ramp is completed.
ƒ Load for Opening : The pressure difference (in bars)
recorded when the valve starts to move from a closed
position.
ƒ Seat Load : The absolute pressure difference in bars
between the supply pressure (spring to open) or air
pressure (spring to close) and the pressure at which
the valve first closes.
ƒ The stroking range is the pressure required to stroke
the valve assembly from the open to the closed posi-
tion and back.
‰
Stroking range o2c close; The pressure difference (in
bars) recorded when the valve starts to move from po-
sition 1% to closed direction.
‰
Stroking range o2c open; The pressure difference (in
bars) recorded when the valve starts to move from po-