Graco 234129, Инструкция по эксплуатации

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Flow Rate Calculation
104 309738L
Flow Rate Calculation
The pulses per flow reading value is calculated by the
system based on the K-factor and the flow rate entered
during flow calibration.
The time is measured for the number of flow meter
pulses in the flow average variable to occur and the flow
rate is calculated.
Example: pulses per reading = 4 pulses
Flow Rate = 400 cc/min
K-factor = 3500 pulses/liter = 3.5 pulses/cc
This gives a pulse rate of 23.3 pulses/second or 43 milli-
seconds/pulse. A new flow rate is measured approxi-
mately every 171 milli-seconds.
If the time measured with the same parameters (3500
pulses/liter, 4 pulses flow average) is 180 milliseconds,
the flow rate calculation would be 380 cc/minute.
Flow Calibration
In order to control the flow rate of a material, the system must determine the pressure required at the regulator outlet
to achieve a desired flow rate (Fig. 20).The flow calibration procedure provides the pressure required to obtain the
maximum desired flow rate (10 VDC flow command.)
4 pulses
(pulses per reading)
F
IG
. 42
0
200
400
600
800
1000
100%
80%
60%
40%
20%
0%
0
2
4
6
8
10
-10%
The flow calibration procedure
determines this point. This is the
initial pressure/flow peak setting
(100%).
This is the
initial pressure
flow offset setting
(0%)
Flow Command (VDC)
10 VDC = flow rate entered on flow calibration screen for 100% flow command
Pressure (psi)
Default flow comp pivot
point (50%). See Control
Assembly Parts on page