Graco PCF Instructions And Parts page 38

Operation
Verify Flow Meter Calibration
Most sealant and adhesive materials are compressible.
Since the flow meter measures the material under high
pressure, the actual volume of material dispensed may
vary slightly from the measured volume, due to this
compressibility. If the K-factor is not correct, the dis-
played volume will not be accurate.
Follow either of the following methods to calibrate the
flow meter during initial setup and on a routine basis to
check for flow meter wear.
Method 1. Using a gram scale
1. Record the flow meter k-factor shown on the Flow-
meter Settings screen (Fluid Plate - screen 4). See
F . 25 on page 31.
IG
2. Use a 500 cc or larger beaker. Measure the mass of
the empty beaker.
3. Manually dispense material into the beaker. Hold
the beaker so that the stream of material is sub-
merged in the captured material to minimize air
entrapment in the container.
4. Record the volume dispensed on the Home screen
1. See F . 30 on page 39.
IG
5. Calculate the actual volume dispensed:
fluid mass (g)
density (g/cc)
6. Calculate the new flow meter K-factor:
displayed volume (cc) x K-Factor (old)
K-Factor (new) =
measured volume (cc)
7. Enter new K-factor.
8. Repeat the procedure to verify the new K-factor.
Method 2. Without using a gram scale, visual measure-
ment
1. Record the flow meter k-factor shown on the Flow-
meter Settings screen (Fluid Plate - screen 4). See
F . 25 on page 31.
IG
2. Use a 500 cc or larger beaker. Measure the mass of
the empty beaker.
38
=
measure volume (cc)
3. Manually dispense material into the beaker. Hold
the beaker so that the stream of material is sub-
merged in the captured material to minimize air
entrapment in the container.
4. Record the volume dispensed on the Home screen
1. See F . 30 on page 39.
IG
5. Settle the material into the beaker and view the
actual volume dispensed.
6. Calculate the new flow meter K-factor:
displayed volume (cc) x K-Factor (old)
K-Factor (new) =
dispensed volume (cc)
7. Enter new K-factor.
8. Repeat the procedure to verify the new K-factor.
Manually Adjust Kp and Ki
NOTE: It is recommended that these values not be
changed from the factory defaults of 32.00 for Kp
and 128.00 for Ki.
If the system is not controlling the desired pressure
while in pressure control mode, manually change the Kp
and Ki values:
• If the regulator outlet pressure does not closely fol-
low the desired pressure increase Kp with the Ki
value set to zero. Continue to increase the Kp value
by increments of one until the proper pressure con-
trol is achieved.
• Decrease Kp if the regulator outlet pressure oscil-
lates rapidly above and below the commanded pres-
sure. Continue to decrease the Kp value by 10%
increments until the outlet pressure is stable.
• Set Ki value to 2 and continue to increase the Ki
value by 2 until the system oscillates.
• Decrease Ki until oscillation stops.
313377B