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Consistency Control Chain Evaluation Procedure
Purpose: To identify any equipment or control strategies
that would contribute to poor consistency control.
TEST TO BE PERFORMED
1) Manual Bump Test
 Place system in manual control
Change dilution control valve position by 10 %.
Return valve to original position
Put system back in automatic control
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Note Time to Meter Response =Dead Time.
Note rate of change and time needed to stabilize.
Note time and rate when valve is returned to original position.
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2) Set Point Change (Loop is in Automatic Control)
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Change setpoint by at least 0.2 % consistency
Return to original setpoint |
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Note time to first response = Dead Time
Time of stabilizing period.
Rate of change to stabilize.
Return to original setting.
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3) Control Loop Information
Average Consistency deviation from setpoint ( 2 min. Minimum time frame )
Gain and Reset for each loop
Dilution Water Header Pressure
Dilution Control Valve Type and size
 How was size determined
Injection point and style
4) Sampling Procedures
How often are samples taken
By whom
Test Method
Sample Valve location & Type of valve
How are sample results used
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