Brooks Instrument 5850EM - Manual (Page 49)

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Brooks ® Models 5964, 5850EM
Section 3 Operation Installation and Operation Manual
X-TMF-5964-5850EM-MFC-eng
Part Number: 541B121AHG
November, 2008
Standard Response and Current I/O PC Board Adjustment #2
(specification guaranteed)
Note: Adjustment of the anticipate potentiometer to obtain a flow rate
performance to be within 2% of flow rate commanded in less than three
seconds (six seconds for Current I/O Version) after command change
requires the use of a fast response flowmeter (500 millisecond response to
be within 0.2% of final value or better) in series with the Model 5850EM
and a storage oscilloscope or recorder.
a. Make a step change in command to the controller from zero to 100% of
full scale flow and record the output signal of the fast response flowme-
ter.
b. If this signal shows more than 4% overshoot, adjust the anticipate
potentiometer one-half to one turn counterclockwise. If the signal does
not show overshoot, but is not within 2% full scale of final value after
three seconds, adjust the anticipate potentiometer one-half to one turn
clockwise. Set the command potentiometer for zero percent of flow.
c. Repeat Steps a and b until the fast response flowmeter output signal
meets the specified response requirements.