Hanna Instruments HI 9910 - Manual (Page 24)

24
ACID
ALK
e.g. Dosing base liquids
Set point = pH 6.00
Measured value = pH 4.00
To adjust the sample stream to the setpoint, you need to
dose base, therefore select "ALK".
FOR HI 9911 (DUAL-POINT ADJUSTMENT)
a) ACID SETPOINT and DOSAGE
Turn the switches to "SET" and “ACID” (see 7 and 8 - Functional
Diagram) to set the upper limit
set the upper limit set the upper limit set the upper limit set the upper limit and to direct the controller to
lower the pH. The display will show the higher setpoint (e.g. pH
7.00).
Using a small screwdriver, adjust the “ACID SET” trimmers. First
adjust the “COARSE” trimmer and then fine tune with the “FINE”
trimmer (see 3 and 4 - Functional Diagram) until the desired set
value is displayed (e.g. pH 8.00).
a) ALKALINE SETPOINT and DOSAGE
Turn the switches to "SET" and “ALK” (see 7/8 - Functional Diagram)
to set the lower limit
set the lower limit set the lower limit set the lower limit set the lower limit and to direct the controller to increase the
pH. The display will show the lower setpoint (e.g. pH 6.00).
7.00
SET
READ
ACID
ALK
pH
COARSE FINE SLOPE OFFSET
ALKALINE SET
ACID SET
7.00
pH
COARSE FINE SLOPE OFFSET
ALKALINE SET
ACID SET
8.00
SET
READ
ACID
ALK
6.00